Internet-Draft Matt Mathis John Heffner Pittsburgh Supercomputing Center Rajiv Raghunarayan Cisco Systems TCP Extended Statistics MIB draft-ietf-tsvwg-tcp-mib-extension-08.txt Sun Oct 23 12:48:11 EDT 2005 Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http:// www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire April 23, 2006 Abstract This draft describes extended performance statistics for TCP. They are designed to use TCP's ideal vantage point to diagnose performance problems in both the network and the application. If a network based application is performing poorly, TCP can determine if the bottleneck is in the sender, the receiver or the network itself. If the bottleneck is in the network, TCP can provide specific information about its nature. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . 2 Mathis, et al [Page 1] Internet-Draft Expires April 23, 2006 Oct 23, 2005 2. The Internet-Standard Management Framework . . . . . . . . 4 3. Overview . . . . . . . . . . . . . . . . . . . . . . . . . 4 4. TCP Extended Statistics MIB . . . . . . . . . . . . . . . . 8 5. Normative References . . . . . . . . . . . . . . . . . . . 58 6. Informative References . . . . . . . . . . . . . . . . . . 59 7. Security Considerations . . . . . . . . . . . . . . . . . . 59 8. Contributors . . . . . . . . . . . . . . . . . . . . . . . 60 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . 60 10. Authors' Addresses . . . . . . . . . . . . . . . . . . . . 60 11. Intellectual Property . . . . . . . . . . . . . . . . . . 61 12. Disclaimer of Validity . . . . . . . . . . . . . . . . . . 61 13. Full Copyright Statement . . . . . . . . . . . . . . . . . 62 1. Introduction This draft describes extended performance statistics for TCP. They are designed to use TCP's ideal vantage point to diagnose performance problems in both the network and the application. If a network based application is performing poorly, TCP can determine if the bottleneck is in the sender, the receiver or the network itself. If the bottleneck is in the network, TCP can provide specific information about its nature. The SNMP objects defined in this draft extend TCP MIB, as specified in RFC 4022 [RFC4022]. This document is automatically generated from a database of potential TCP instruments. Beware that the OIDs are still likely to change with future versions. The most current version can be obtained from http://www.web100.org/mib/ . Please use tsvwg@ietf.org to send comments to the entire TSV WG. X. Changes This virtual section will be removed as the draft nears completion. Changes since draft-ietf-tsvwg-tcp-mib-extension-07.txt (20-Feb-2005) Added tcpEStatsStackSpuriousRtoDetected. Renamed AckAfterFR to tcpEStatsStackSpuriousFrDetected and clarified the description. Restructure the tables yet again. The perf, path, and stack tables now each start out with some required objects, followed by optional objects. This permits a much more logical grouping of instruments, lowers the cost for a minimal implementation and encourages incremental deployment. Mathis, et al [Page 2] Internet-Draft Expires April 23, 2006 Oct 23, 2005 Changes since draft-ietf-tsvwg-tcp-mib-extension-06.txt (20-Feb-2005) Added tcpEStatsPerfPipeSize and tcpEStatsPerfMaxPipeSize to detect when TCP is unable to open the window as large as permitted. Added tcpEStatsStackInRecovery to indicate if the connection is currently in recovery (e.g. has outstanding retransmissions), or about to enter recovery. Move tcpEStatsPerfSumRTT, Tcpestatsperfhcsumrtt and tcpEStatsPerfCountRTT to the path table, tcpEStatsPath. Added tcpEStatsPathHCGroup. Move tcpEstatsPathAckAfterFR and tcpEstatsPathSndDupAckEpisodes back to the performance table, tcpEStatsPerf. Move tcpEStatsPerfSampleRTT, tcpEStatsPerfSampleRTT and tcpEStatsPerfSampleRTT to the stack table, tcpEStatsStack. Clarified the descriptions of tcpEStatsPerfDupAckEpisodes, tcpEStatsPerfDupAcksOut and tcpEStatsPerfCongSignals Changes since draft-ietf-tsvwg-tcp-mib-extension-05.txt (17-July-2004) Many changes to object descriptions MIB comments and overview to improve clarity. Completely restructured the per connection tables. Seven table were reduced to five. The main per connection table tcpEStatsPerfTable is now mandatory. Three other new tables are focused on understanding the details of the behavior of the path, internal TCP algorithms and the application. In addition, there is a new tuning table with per-connection writable controls to work around a number of common problems. Note that due to the table restructuring, most of the object names listed below have changed. Restructured the Listen Table (tcpEStatsListenerTable) to better instrument various SYN flood defenses. Removed minimal receiver window objects, and replaced them by the count of the number of transitions to zero window from non-zero window. Replaced tcpEStatsPathIpTos by tcpEStatsPathIpTosOut and added tcpEStatsPathIpTosIn. Mathis, et al [Page 3] Internet-Draft Expires April 23, 2006 Oct 23, 2005 Updated the descriptions of tcpEStatsDataSndNxt, tcpEStatsDataSndMax, tcpEStatsDataThruOctetsAcked, tcpEStatsDataHCThruBytesAcked, tcpEStatsDataThruBytesReceived, tcpEStatsDataHCThruBytesReceived, consistiently use RFC791 variables (SND.NXT, etc) or refer to other TCP-ESTATS-MIB objects. Changed tcpEStatsSynOptsMSSSent and tcpEStatsSynOptsMSSRcvd from Gauge32 to Unsigned32 Updated descriptions of tcpEStatsConnectLocalAddress and tcpEStatsConnectRemAddress to new conventions for InetAddress [RFC4001] Changes since draft-ietf-tsvwg-tcp-mib-extension-04.txt (27-Oct-2003) Updated ID boiler plate to RFC3668, ID-Guidelines and fixed some formatting glitches Added a Table of Contents Updated the description of tcpEStatsConnectionState to indicate that the listen state included only for document parallelism and should not be used. Explained why it is useful for tcpEStatsConnectIdTable and others to remain for 30 seconds after a connection closes (so you retrieve the total statistics for the entire connection). Added comment about not supporting writing DeleteTcb into the TCP State. Explained that SndNxt is not a counter because it is non-monotonic. Clarified StartTime to be row creation Clarified row creation to be at the first SYN unless techniques to defend against SYN floods are in effect, then at connection establishment. Added tcpEStatsControlNotify to control the generation of notifications. Changed sequence numbers from ZeroBasedCounter32 to Counter32. Changes since draft-ietf-tsvwg-tcp-mib-extension-03.txt (2-Mar-2003) Replaced "queued" with "buffered by TCP" Changed all counters in the TCP connection tables to be ZeroBased Mathis, et al [Page 4] Internet-Draft Expires April 23, 2006 Oct 23, 2005 Remove tcpEStatsHCInSegs, tcpEStatsHCOutSegs, which appear in as tcpHCInSegs and tcpHCOutSegs in draft-ietf-ipv6-rfc2012-update-03.txt and later drafts. Added changes section. 2. The Internet-Standard Management Framework For a detailed overview of the documents that describe the current Internet-Standard Management Framework, please refer to section 7 of RFC 3410 [RFC3410]. Managed objects are accessed via a virtual information store, termed the Management Information Base or MIB. MIB objects are generally accessed through the Simple Network Management Protocol (SNMP). Objects in the MIB are defined using the mechanisms defined in the Structure of Management Information (SMI). This memo specifies a MIB module that is compliant to the SMIv2, which is described in STD 58, RFC 2578 [RFC2578], STD 58, RFC 2579 [RFC2579] and STD 58, RFC 2580 [RFC2580]. 3. Overview The TCP-ESTATS-MIB defined in this memo consists of 6 tables, two groups of scalars and two notifications: - The first group of scalars in this MIB contain a statistic of a TCP protocol engine not covered in RFC 4022. The scalar tcpEStatsListenerTableLastChange, provides management stations with an an easier mechanism to validate their listener caches. - The second group of scalars consist of knobs to enable and disable information collection by the tables containing connection-related statistics/information. For example the tcpEStatsControlPath object controls the activation of the tcpEStatsPathTable. The tcpEStatsConnTableLatency object determines how long table rows are retained after connection close, to permit reading final connection completion statistics. Changing any of these controls may affect the correctness of other management applications accessing this MIB. Generally local policy should only permit limited write access to these controls (e.g. only by one management station or only during system configuration). Mathis, et al [Page 5] Internet-Draft Expires April 23, 2006 Oct 23, 2005 - The tcpEStatsListenerTable provides information on the active TCP listeners on a device. It supports objects to monitor and diagnose SYN-flood denial-of-service attacks as described below. - The ZeroBasedCounter32 and ZeroBasedCounter64 objects in the tcpEStatsListenerTable and tcpEStatsListenerTable are initialized to zero when the table row is created. - The tcpEStatsConnectIdTable provides a mapping between the connection indices i.e. source address type, source address, source port, destination address type, destination address and destination port, and the connection index. The connection index is used to index into most of the remaining tables in this MIB module, and is designed to facilitate rapid polling of multiple objects associated with one TCP connection. - The tcpEStatsPerfTable contains objects that are useful for measuring TCP performance and first check problem diagnosis. - The tcpEStatsPathTable contains objects that can be used to infer detailed behavior of the Internet path, such as the extent that there are losses or segment reordering, etc. - The tcpEStatsStackTable contains objects that are most useful for determining how well the TCP control algorithms are coping with this particular path. - The tcpEStatsAppTable provides objects that are useful for determining if the application using TCP is limiting TCP performance. - The tcpEStatsTuneTable provides per connection controls that can be used to work around a number of common problems that plague TCP over some paths. - The two notifications defined in this MIB module are tcpEStatsEstablishNotification, indicating that a new connection has been accepted (or established see below), and tcpEStatsCloseNotification, indicating that an existing connection has recently closed. - The tcpEStatsListenerTable is specifically designed to provides information that is useful for diagnosing SYN-flood Denial-of-Service attacks, where a server is overwhelmed by forged or otherwise malicious connection attempts. There are several different techniques that are used to defend against SYN-flooding but none are standardized, and most Mathis, et al [Page 6] Internet-Draft Expires April 23, 2006 Oct 23, 2005 have never been well described in the literature (ergo there are no normative references). These different techniques all have the same basic characteristics which are instrumentable with a common set of objects even though the techniques differ greatly in the details. All SYN-flood defenses avoid allocating significant resources (memory or CPU) to incoming (passive open) connections until the connections meet some liveness criteria (to defend against forged IP source addresses) and the server has sufficient resources to process the incoming request. Note that allocating resources is an implementation specific event that may not correspond to a observable protocol event (e.g. segments on the wire). There are two general concepts that can be applied to all known SYN-flood defenses. There is generally a well defined event when a connection is allocated full resources, and a "backlog" - a queue of embryonic connections that have been allocated only partial resources. In many implementations incoming TCP connections are allocated resources as a side affect of the POSIX [POSIX] accept() call. For this reason we use the terminology "accepting a connection" to refer to this event: committing sufficient network resources to process the incoming request. Accepting a connection typically entails allocating memory for the protocol control block [RFC793], the per connection table rows described in this MIB and CPU resources, such as process table entries or threads. Note that it is not useful to accept connections before they are ESTABLISHED, because this would create an easy opportunity for Denial-of-Service attacks, using forged source IP addresses. The backlog consists of connections that are in SYN-RCVD or ESTABLISHED states, that have not been accepted. For purposes of this MIB we assume that these connections have been allocated some resources (e.g. an embryonic protocol control block) but not full resources (e.g. do not yet have MIB table rows). Note that some SYN-Flood defenses dispense with explicit SYN-RCVD state by cryptographically encoding the state in the ISS of the SYN-ACK, and then using the sequence number of the first ACK to reconstruct the SYN-RCVD state before transitioning to the ESTABLISHED state. For these implementations there is no explicit representation of the Mathis, et al [Page 7] Internet-Draft Expires April 23, 2006 Oct 23, 2005 SYN-RCVD state and the backlog only consists of connections that are ESTABLISHED and are waiting to be ACCEPTED. Furthermore, most SYN-flood defenses have some mechanism to throttle connections that might otherwise overwhelm this endpoint. They generally use some combination of discarding incoming SYNs and discarding connections already in the backlog. This does not cause all connections from legitimate clients to fail, as long as the clients retransmit the SYN or first ACK as specified in RFC793. Most of the diversity in SYN flood defenses arises in variations in these algorithms to limit load, and therefore they can not conveniently be instrumented with a common standard MIB. The Listen Table instruments all passively opened TCP connections in terms of observable protocol events (e.g. sent and received segments) and resource allocation events (entering the backlog and being accepted). This approach eases generalization to SYN-flood mechanisms that use alternate TCP state transition diagrams and implicit mechanisms to encode some states. 4. TCP Extended Statistics MIB TCP-ESTATS-MIB DEFINITIONS ::= BEGIN IMPORTS MODULE-IDENTITY, Counter32, Integer32, Unsigned32, Gauge32, OBJECT-TYPE, experimental, NOTIFICATION-TYPE FROM SNMPv2-SMI MODULE-COMPLIANCE, OBJECT-GROUP, NOTIFICATION-GROUP FROM SNMPv2-CONF ZeroBasedCounter32 FROM RMON2-MIB -- [RFC2021] ZeroBasedCounter64 FROM HCNUM-TC -- [RFC2856] TEXTUAL-CONVENTION, DateAndTime, TruthValue, TimeStamp FROM SNMPv2-TC InetAddressType, InetAddress, InetPortNumber FROM INET-ADDRESS-MIB -- [RFC4001] tcpListenerEntry FROM TCP-MIB; -- [RFC4022] Mathis, et al [Page 8] Internet-Draft Expires April 23, 2006 Oct 23, 2005 tcpEStatsMIB MODULE-IDENTITY LAST-UPDATED "200510231248Z" -- Oct 23, 2005 ORGANIZATION "IETF TSV Working Group" CONTACT-INFO "Matt Mathis John Heffner Raghu Reddy Web100 Project Pittsburgh Supercomputing Center 4400 Fifth Ave Pittsburgh, PA 15213 Email: mathis@psc.edu, jheffner@psc.edu, rreddy@psc.edu Rajiv Raghunarayan Cisco Systems Inc. San Jose, CA 95134 Phone: 408 853 9612 Email: raraghun@cisco.com Jon Saperia JDS Consulting, Inc. 174 Chapman Street Watertown, MA 02472 Phone: 617-744-1079 Email: saperia@jdscons.com " DESCRIPTION "Documentation of TCP Extended Performance Instrumentation variables from the Web100 project. [Web100] Copyright (C) The Internet Society (2005). This version of this MIB module is a part of RFC xxxx; see the RFC itself for full legal notices." -- RFC Editor: replace xxxx with actual RFC number & remove note REVISION "200510231248Z" -- Oct 23, 2005 DESCRIPTION "Initial version, published as RFC xxxx." -- RFC Editor assigns RFC xxxx ::= { experimental 9999 } -- IANA assigns base OID xxxx tcpEStatsNotifications OBJECT IDENTIFIER ::= { tcpEStatsMIB 0 } tcpEStatsMIBObjects OBJECT IDENTIFIER ::= { tcpEStatsMIB 1 } tcpEStatsConformance OBJECT IDENTIFIER ::= { tcpEStatsMIB 2 } tcpEStats OBJECT IDENTIFIER ::= { tcpEStatsMIBObjects 1 } tcpEStatsControl OBJECT IDENTIFIER ::= { tcpEStatsMIBObjects 2 } tcpEStatsScalar OBJECT IDENTIFIER ::= { tcpEStatsMIBObjects 3 } -- Mathis, et al [Page 9] Internet-Draft Expires April 23, 2006 Oct 23, 2005 -- Textual Conventions -- TcpEStatsOperation ::= TEXTUAL-CONVENTION STATUS current DESCRIPTION "Indicates whether the table or notification controlled by an object with this syntax is enabled or in a disabled state." SYNTAX INTEGER { enabled(1), disabled(2) } -- -- TCP Extended statistics scalars -- tcpEStatsListenerTableLastChange OBJECT-TYPE SYNTAX TimeStamp MAX-ACCESS read-only STATUS current DESCRIPTION "The value of sysUpTime at the time of the last creation or deletion of an entry in the tcpListenerTable. If the number of entries has been unchanged since the last re-initialization of the local network management subsystem, then this object contains a zero value." ::= { tcpEStatsScalar 3 } -- ================================================================ -- -- The tcpEStatsControl Group -- -- The scalar objects in this group are used to control the -- activation and deactivation of the TCP Extended Statistics -- tables and notifications in this module. -- tcpEStatsControlPath OBJECT-TYPE SYNTAX TcpEStatsOperation MAX-ACCESS read-write STATUS current DESCRIPTION "Controls the activation of the TCP Path Statistics table." DEFVAL { disabled } Mathis, et al [Page 10] Internet-Draft Expires April 23, 2006 Oct 23, 2005 ::= { tcpEStatsControl 1 } tcpEStatsControlStack OBJECT-TYPE SYNTAX TcpEStatsOperation MAX-ACCESS read-write STATUS current DESCRIPTION "Controls the activation of the TCP Stack Statistics table." DEFVAL { disabled } ::= { tcpEStatsControl 2 } tcpEStatsControlApp OBJECT-TYPE SYNTAX TcpEStatsOperation MAX-ACCESS read-write STATUS current DESCRIPTION "Controls the activation of the TCP Application Statistics table." DEFVAL { disabled } ::= { tcpEStatsControl 3 } tcpEStatsControlTune OBJECT-TYPE SYNTAX TcpEStatsOperation MAX-ACCESS read-write STATUS current DESCRIPTION "Controls the activation of the TCP Tuning table." DEFVAL { disabled } ::= { tcpEStatsControl 4 } tcpEStatsControlNotify OBJECT-TYPE SYNTAX TcpEStatsOperation MAX-ACCESS read-write STATUS current DESCRIPTION "Controls the generation of all notifications defined in this MIB." DEFVAL { disabled } ::= { tcpEStatsControl 5 } tcpEStatsConnTableLatency OBJECT-TYPE SYNTAX Integer32 (0..30) MAX-ACCESS read-only STATUS current DESCRIPTION "Specifies the number of seconds that the entity will Mathis, et al [Page 11] Internet-Draft Expires April 23, 2006 Oct 23, 2005 retain entries in the TCP connection tables, after the connection first enters the closed state. The entity SHOULD provide a configuration option to enable customization of this value. A value of 0 results in entries being removed from the tables as soon as the connection enters the closed state. The value of this object pertains to the following tables: tcpEStatsConnectIdTable tcpEStatsPerfTable tcpEStatsPathTable tcpEStatsStackTable tcpEStatsAppTable tcpEStatsTuneTable" ::= { tcpEStatsControl 6 } -- ================================================================ -- -- Listener Table -- tcpEStatsListenerTable OBJECT-TYPE SYNTAX SEQUENCE OF TcpEStatsListenerEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "This table contains information about TCP Listeners, in addition to the information maintained by the tcpListenerTable RFC4022." ::= { tcpEStats 10 } tcpEStatsListenerEntry OBJECT-TYPE SYNTAX TcpEStatsListenerEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "Each entry in the table contains information about a specific TCP Listener." AUGMENTS { tcpListenerEntry } ::= { tcpEStatsListenerTable 1 } TcpEStatsListenerEntry ::= SEQUENCE { tcpEStatsListenerStartTime TimeStamp, tcpEStatsListenerSynRcvd ZeroBasedCounter32, tcpEStatsListenerInitial ZeroBasedCounter32, tcpEStatsListenerEstablished ZeroBasedCounter32, tcpEStatsListenerAccepted ZeroBasedCounter32, tcpEStatsListenerExceedBacklog ZeroBasedCounter32, tcpEStatsListenerHCSynRcvd ZeroBasedCounter64, Mathis, et al [Page 12] Internet-Draft Expires April 23, 2006 Oct 23, 2005 tcpEStatsListenerHCInitial ZeroBasedCounter64, tcpEStatsListenerHCEstablished ZeroBasedCounter64, tcpEStatsListenerHCAccepted ZeroBasedCounter64, tcpEStatsListenerHCExceedBacklog ZeroBasedCounter64, tcpEStatsListenerCurrConns Gauge32, tcpEStatsListenerMaxBacklog Integer32, tcpEStatsListenerCurBacklog Gauge32, tcpEStatsListenerCurEstabBacklog Gauge32 } tcpEStatsListenerStartTime OBJECT-TYPE SYNTAX TimeStamp MAX-ACCESS read-only STATUS current DESCRIPTION "The value of sysUpTime at the time this listener was established. If the current state was entered prior to the last re-initialization of the local network management subsystem, then this object contains a zero value." ::= { tcpEStatsListenerEntry 1 } tcpEStatsListenerSynRcvd OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of SYNs which have been received for this listener. The total number of failed connections for all reasons can be estimated to be tcpEStatsListenerSynRcvd minus tcpEStatsListenerAccepted and tcpEStatsListenerCurBacklog." ::= { tcpEStatsListenerEntry 2 } tcpEStatsListenerInitial OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The total number of connections for which the Listener has allocated initial state and placed the connection in the backlog. The may happen in the SYN-RCVD or ESTABLISHED states, depending on the implementation." ::= { tcpEStatsListenerEntry 3 } tcpEStatsListenerEstablished OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only Mathis, et al [Page 13] Internet-Draft Expires April 23, 2006 Oct 23, 2005 STATUS current DESCRIPTION "The number of connections which have been established to this endpoint. E.g. The number of first ACKs which have been received for this listener." ::= { tcpEStatsListenerEntry 4 } tcpEStatsListenerAccepted OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The total number of connections for which the Listener has successfully issued an accept, removing the connection from the backlog." ::= { tcpEStatsListenerEntry 5 } tcpEStatsListenerExceedBacklog OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The total number of connections dropped from the backlog by this listener due to all reasons. This includes all connections that are allocated initial resources but are not accepted for some reason." ::= { tcpEStatsListenerEntry 6 } tcpEStatsListenerHCSynRcvd OBJECT-TYPE SYNTAX ZeroBasedCounter64 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of SYNs which have been received for this listener on systems that can process (or reject) more than 1 million connections per second. See tcpEStatsListenerSynRcvd." ::= { tcpEStatsListenerEntry 7 } tcpEStatsListenerHCInitial OBJECT-TYPE SYNTAX ZeroBasedCounter64 MAX-ACCESS read-only STATUS current DESCRIPTION "The total number of connections for which the Listener has allocated initial state and placed the connection in the backlog on systems that can process (or reject) more than 1 million connections per second. See Mathis, et al [Page 14] Internet-Draft Expires April 23, 2006 Oct 23, 2005 tcpEStatsListenerInitial." ::= { tcpEStatsListenerEntry 8 } tcpEStatsListenerHCEstablished OBJECT-TYPE SYNTAX ZeroBasedCounter64 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of connections which have been established to this endpoint on systems that can process (or reject) more than 1 million connections per second. See tcpEStatsListenerEstablished." ::= { tcpEStatsListenerEntry 9 } tcpEStatsListenerHCAccepted OBJECT-TYPE SYNTAX ZeroBasedCounter64 MAX-ACCESS read-only STATUS current DESCRIPTION "The total number of connections for which the Listener has successfully issued an accept, removing the connection from the backlog on systems that can process (or reject) more than 1 million connections per second. See tcpEStatsListenerAccepted." ::= { tcpEStatsListenerEntry 10 } tcpEStatsListenerHCExceedBacklog OBJECT-TYPE SYNTAX ZeroBasedCounter64 MAX-ACCESS read-only STATUS current DESCRIPTION "The total number of connections dropped from the backlog by this listener due to all reasons on systems that can process (or reject) more than 1 million connections per second. See tcpEStatsListenerHCExceedBacklog." ::= { tcpEStatsListenerEntry 11 } tcpEStatsListenerCurrConns OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The current number of connections in the ESTABLISHED state, which have also been accepted. It excludes connections that have been established but not accepted because they are still subject to being discarded to shed load without explicit action by either endpoint." Mathis, et al [Page 15] Internet-Draft Expires April 23, 2006 Oct 23, 2005 ::= { tcpEStatsListenerEntry 12 } tcpEStatsListenerMaxBacklog OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-only STATUS current DESCRIPTION "The maximum number of connections allowed in backlog at one time." ::= { tcpEStatsListenerEntry 13 } tcpEStatsListenerCurBacklog OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The current number of connections that are in backlog. This counter MUST include connections in ESTABLISHED state, for which the Listener has not yet issued an accept, and MAY include connections in SYN-RECEIVED state." ::= { tcpEStatsListenerEntry 14 } tcpEStatsListenerCurEstabBacklog OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The current number of connections in backlog that are in the ESTABLISHED state, but for which the Listener has not yet issued an accept." ::= { tcpEStatsListenerEntry 15 } -- ================================================================ -- -- TCP Connection ID Table -- -- There is overlap with the RFC 4022 [RFC4022] TCP Connection table -- because there is a semantic difference in the latency of row -- removal in this table. Rows are expected to remain in this -- table longer than in a standard TCP Connection table. Other -- than this latency difference, the semantics of the first six -- objects in this table are the same as the TCP Connection -- table and the DESCRIPTIONS come from RFC 4022. tcpEStatsConnectIdTable OBJECT-TYPE SYNTAX SEQUENCE OF TcpEStatsConnectIdEntry Mathis, et al [Page 16] Internet-Draft Expires April 23, 2006 Oct 23, 2005 MAX-ACCESS not-accessible STATUS current DESCRIPTION "This table maps a connection ID used by other tables in this MIB Module with the information that uniquely identifies each active TCP connection. Entries are retained in this table for the number of seconds indicated by the tcpEStatsConnTableLatency object, after the TCP connection first enters the closed state." ::= { tcpEStats 1 } tcpEStatsConnectIdEntry OBJECT-TYPE SYNTAX TcpEStatsConnectIdEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "Each entry in this table maps a TCP connection 4-tuple to a connection index." INDEX { tcpEStatsConnectLocalAddressType, tcpEStatsConnectLocalAddress, tcpEStatsConnectLocalPort, tcpEStatsConnectRemAddressType, tcpEStatsConnectRemAddress, tcpEStatsConnectRemPort } ::= { tcpEStatsConnectIdTable 1 } TcpEStatsConnectIdEntry ::= SEQUENCE { tcpEStatsConnectLocalAddressType InetAddressType, tcpEStatsConnectLocalAddress InetAddress, tcpEStatsConnectLocalPort InetPortNumber, tcpEStatsConnectRemAddressType InetAddressType, tcpEStatsConnectRemAddress InetAddress, tcpEStatsConnectRemPort InetPortNumber, tcpEStatsConnectIndex Unsigned32 } tcpEStatsConnectLocalAddressType OBJECT-TYPE SYNTAX InetAddressType MAX-ACCESS not-accessible STATUS current DESCRIPTION "The address type of tcpEStatsConnectLocalAddress." ::= { tcpEStatsConnectIdEntry 1 } tcpEStatsConnectLocalAddress OBJECT-TYPE SYNTAX InetAddress MAX-ACCESS not-accessible STATUS current Mathis, et al [Page 17] Internet-Draft Expires April 23, 2006 Oct 23, 2005 DESCRIPTION "The local IP address for this TCP connection. The type of this address is determined by the value of tcpEStatsConnectLocalAddressType. As this object is used in the index for the tcpEStatsConnectIdTable, implementors of this table should be careful not to create entries that would result in OIDs with more than 128 sub-identifiers; else the information cannot be accessed using SNMPv1, SNMPv2c or SNMPv3." ::= { tcpEStatsConnectIdEntry 2 } tcpEStatsConnectLocalPort OBJECT-TYPE SYNTAX InetPortNumber MAX-ACCESS not-accessible STATUS current DESCRIPTION "The local port number for this TCP connection." ::= {tcpEStatsConnectIdEntry 3 } tcpEStatsConnectRemAddressType OBJECT-TYPE SYNTAX InetAddressType MAX-ACCESS not-accessible STATUS current DESCRIPTION "The address type of tcpEStatsConnectRemAddress." ::= { tcpEStatsConnectIdEntry 4 } tcpEStatsConnectRemAddress OBJECT-TYPE SYNTAX InetAddress MAX-ACCESS not-accessible STATUS current DESCRIPTION "The remote IP address for this TCP connection. The type of this address is determined by the value of tcpEStatsConnectRemAddressType. As this object is used in the index for the tcpEStatsConnectIdTable, implementors of this table should be careful not to create entries that would result in OIDs with more than 128 sub-identifiers; else the information cannot be accessed using SNMPv1, SNMPv2c or SNMPv3." ::= { tcpEStatsConnectIdEntry 5 } tcpEStatsConnectRemPort OBJECT-TYPE SYNTAX InetPortNumber MAX-ACCESS not-accessible STATUS current Mathis, et al [Page 18] Internet-Draft Expires April 23, 2006 Oct 23, 2005 DESCRIPTION "The remote port number for this TCP connection." ::= { tcpEStatsConnectIdEntry 6 } tcpEStatsConnectIndex OBJECT-TYPE SYNTAX Unsigned32 MAX-ACCESS read-only STATUS current DESCRIPTION "A unique integer value assigned to each TCP Connection entry. Assignment will begin at 1 and increase to the maximum value and then start again at 1 skipping in use values." ::= { tcpEStatsConnectIdEntry 7 } -- ================================================================ -- -- Basic TCP Performance Statistics -- tcpEStatsPerfTable OBJECT-TYPE SYNTAX SEQUENCE OF TcpEStatsPerfEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "This table contains objects that are useful for measuring TCP performance and first line problem diagnosis. Most objects in this table directly expose some TCP state variable or are easily implemented as simple functions (e.g. Maximum) of TCP state variables." ::= { tcpEStats 2 } tcpEStatsPerfEntry OBJECT-TYPE SYNTAX TcpEStatsPerfEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "Each entry in this table has information about the characteristics of each active and recently closed tcp connection." INDEX { tcpEStatsConnectIndex } ::= { tcpEStatsPerfTable 1 } TcpEStatsPerfEntry ::= SEQUENCE { tcpEStatsPerfSegsOut ZeroBasedCounter32, tcpEStatsPerfDataSegsOut ZeroBasedCounter32, Mathis, et al [Page 19] Internet-Draft Expires April 23, 2006 Oct 23, 2005 tcpEStatsPerfDataOctetsOut ZeroBasedCounter32, tcpEStatsPerfHCDataOctetsOut ZeroBasedCounter64, tcpEStatsPerfSegsRetrans ZeroBasedCounter32, tcpEStatsPerfOctetsRetrans ZeroBasedCounter32, tcpEStatsPerfSegsIn ZeroBasedCounter32, tcpEStatsPerfDataSegsIn ZeroBasedCounter32, tcpEStatsPerfDataOctetsIn ZeroBasedCounter32, tcpEStatsPerfHCDataOctetsIn ZeroBasedCounter64, tcpEStatsPerfElapsedSecs ZeroBasedCounter32, tcpEStatsPerfElapsedMicroSecs ZeroBasedCounter32, tcpEStatsPerfStartTimeStamp DateAndTime, tcpEStatsPerfCurMSS Gauge32, tcpEStatsPerfPipeSize Gauge32, tcpEStatsPerfMaxPipeSize Gauge32, tcpEStatsPerfSmoothedRTT Gauge32, tcpEStatsPerfCurRTO Gauge32, tcpEStatsPerfCongSignals ZeroBasedCounter32, tcpEStatsPerfCurCwnd Gauge32, tcpEStatsPerfCurSsthresh Gauge32, tcpEStatsPerfTimeouts ZeroBasedCounter32, tcpEStatsPerfCurRwinSent Gauge32, tcpEStatsPerfMaxRwinSent Gauge32, tcpEStatsPerfZeroRwinSent Gauge32, tcpEStatsPerfCurRwinRcvd Gauge32, tcpEStatsPerfMaxRwinRcvd Gauge32, tcpEStatsPerfZeroRwinRcvd Gauge32, tcpEStatsPerfSndLimTransRwin ZeroBasedCounter32, tcpEStatsPerfSndLimTransCwnd ZeroBasedCounter32, tcpEStatsPerfSndLimTransSnd ZeroBasedCounter32, tcpEStatsPerfSndLimTimeRwin ZeroBasedCounter32, tcpEStatsPerfSndLimTimeCwnd ZeroBasedCounter32, tcpEStatsPerfSndLimTimeSnd ZeroBasedCounter32 } -- -- The following objects provide statistics on aggregate -- segments and data sent on a connection. These provide a -- direct measure of the Internet capacity consumed by a -- connection. -- tcpEStatsPerfSegsOut OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The total number of segments sent." ::= { tcpEStatsPerfEntry 1 } Mathis, et al [Page 20] Internet-Draft Expires April 23, 2006 Oct 23, 2005 tcpEStatsPerfDataSegsOut OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of segments sent containing a positive length data segment." ::= { tcpEStatsPerfEntry 2 } tcpEStatsPerfDataOctetsOut OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of octets of data contained in transmitted segments, including retransmitted data. Note that this does not include TCP headers." ::= { tcpEStatsPerfEntry 3 } tcpEStatsPerfHCDataOctetsOut OBJECT-TYPE SYNTAX ZeroBasedCounter64 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of octets of data contained in transmitted segments, including retransmitted data, on systems that can transmit more than 10 million bits per second. Note that this does not include TCP headers." ::= { tcpEStatsPerfEntry 4 } tcpEStatsPerfSegsRetrans OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of segments transmitted containing at least some retransmitted data." ::= { tcpEStatsPerfEntry 5 } tcpEStatsPerfOctetsRetrans OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of octets retransmitted." ::= { tcpEStatsPerfEntry 6 } tcpEStatsPerfSegsIn OBJECT-TYPE Mathis, et al [Page 21] Internet-Draft Expires April 23, 2006 Oct 23, 2005 SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The total number of segments received." ::= { tcpEStatsPerfEntry 7 } tcpEStatsPerfDataSegsIn OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of segments received containing a positive length data segment." ::= { tcpEStatsPerfEntry 8 } tcpEStatsPerfDataOctetsIn OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of octets contained in received data segments, including retransmitted data. Note that this does not include TCP headers." ::= { tcpEStatsPerfEntry 9 } tcpEStatsPerfHCDataOctetsIn OBJECT-TYPE SYNTAX ZeroBasedCounter64 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of octets contained in received data segments, including retransmitted data, on systems that can receive more than 10 million bits per second. Note that this does not include TCP headers." ::= { tcpEStatsPerfEntry 10 } tcpEStatsPerfElapsedSecs OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The seconds part of the time elapsed between tcpEStatsPerfStartTimeStamp and the most recent protocol event (segment sent or received)." ::= { tcpEStatsPerfEntry 11 } tcpEStatsPerfElapsedMicroSecs OBJECT-TYPE Mathis, et al [Page 22] Internet-Draft Expires April 23, 2006 Oct 23, 2005 SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The micro-second part of time elapsed between tcpEStatsPerfStartTimeStamp to the most recent protocol event (segment sent or received). This may be updated in what ever time granularity is the system supports." ::= { tcpEStatsPerfEntry 12 } tcpEStatsPerfStartTimeStamp OBJECT-TYPE SYNTAX DateAndTime MAX-ACCESS read-only STATUS current DESCRIPTION "Time at which this row was created and all ZeroBasedCounters in the row were initialized to zero." ::= { tcpEStatsPerfEntry 13 } -- -- The following objects can be used to fit minimal -- performance models to the TCP data rate. -- tcpEStatsPerfCurMSS OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The current maximum segment size (MSS), in octets." ::= { tcpEStatsPerfEntry 14 } tcpEStatsPerfPipeSize OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The TCP senders current estimate of the number of unacknowledged data octets in the network. While not in recovery, this is the same as ``Flight Size'' as defined in RFC2581. While in recovery, this is the same as ``pipe'' as defined in RFC3517. If RFC3517 is not in effect, the data octets in flight can be estimated as SND.NXT minus SND.UNA plus any Mathis, et al [Page 23] Internet-Draft Expires April 23, 2006 Oct 23, 2005 retransmitted data, minus some measure of the data that has left the network. For example, with Reno or NewReno style TCP, the number of duplicate acknowledgement is used to count the number of segments that have left the network. I.e.: PipeSize=SND.NXT-SND.UNA+(retransmits-dupacks)*CurMSS" ::= { tcpEStatsPerfEntry 15 } tcpEStatsPerfMaxPipeSize OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The maximum value of tcpEStatsPerfPipeSize, for this connection." ::= { tcpEStatsPerfEntry 16 } tcpEStatsPerfSmoothedRTT OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The smoothed round trip time, in milliseconds, used in calculation of the RTO. See SRTT in [RFC2988]." ::= { tcpEStatsPerfEntry 17 } tcpEStatsPerfCurRTO OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The current value of the retransmit timer RTO, in milliseconds. See [RFC2988]." ::= { tcpEStatsPerfEntry 18 } tcpEStatsPerfCongSignals OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of multiplicative downward congestion window adjustments due to all forms of congestion signals, including Fast Retransmit, ECN and timeouts. This object summarizes all events that invoke the MD portion of AIMD congestion control, and as such is the best indicator of how cwnd is being affected by congestion. Note that retransmission timeouts multiplicatively reduce the window implicitly by setting ssthresh, and should be Mathis, et al [Page 24] Internet-Draft Expires April 23, 2006 Oct 23, 2005 included in tcpEStatsPerfCongSignals. In order to minimize spurious congestion indications due to out-of-order segments, tcpEStatsPerfCongSignals should be incremented in association with the Fast Retransmit algorithm." ::= { tcpEStatsPerfEntry 19 } tcpEStatsPerfCurCwnd OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The current congestion window, in octets. See [RFC2581]." ::= { tcpEStatsPerfEntry 20 } tcpEStatsPerfCurSsthresh OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The current slow start threshold in octets. See [RFC2581]." ::= { tcpEStatsPerfEntry 21 } tcpEStatsPerfTimeouts OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of times the retransmit timeout has expired when the RTO backoff multiplier is equal to one. See [RFC2988]." ::= { tcpEStatsPerfEntry 22 } -- -- The following objects instrument our receiver window -- updates to the remote sender. These can be used to -- determine if the local receiver is exerting flow control -- back pressure on the remote sender. -- tcpEStatsPerfCurRwinSent OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The most recent window advertisement sent, in octets." ::= { tcpEStatsPerfEntry 23 } tcpEStatsPerfMaxRwinSent OBJECT-TYPE SYNTAX Gauge32 Mathis, et al [Page 25] Internet-Draft Expires April 23, 2006 Oct 23, 2005 MAX-ACCESS read-only STATUS current DESCRIPTION "The maximum window advertisement sent, in octets." ::= { tcpEStatsPerfEntry 24 } tcpEStatsPerfZeroRwinSent OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of acknowledgments sent announcing a zero receive window, when the previously announced window was not zero." ::= { tcpEStatsPerfEntry 25 } -- -- The following objects instrument receiver window updates -- from the far end-system to determine if the remote receiver -- has sufficient buffer space or is exerting flow-control -- back pressure on the local sender. -- tcpEStatsPerfCurRwinRcvd OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The most recent window advertisement received, in octets." ::= { tcpEStatsPerfEntry 26 } tcpEStatsPerfMaxRwinRcvd OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The maximum window advertisement received, in octets." ::= { tcpEStatsPerfEntry 27 } tcpEStatsPerfZeroRwinRcvd OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of acknowledgments received announcing a zero receive window, when the previously announced window was not zero." ::= { tcpEStatsPerfEntry 28 } Mathis, et al [Page 26] Internet-Draft Expires April 23, 2006 Oct 23, 2005 -- -- The following optional objects can be used to quickly -- identify which subsystems are limiting TCP performance. -- There are three parallel pairs of instruments that measure -- the extent to which TCP performance is limited by the -- announced receiver window (indicating a receiver -- bottleneck), the current congestion window or -- retransmission timeout (indicating a path bottleneck) and -- all others events (indicating a sender bottleneck). -- -- These instruments should be updated every time the TCP -- output routine stops sending data. The elapsed time since -- the previous stop is accumulated into the appropriate -- object as determined by the previous stop reason (e.g. stop -- state). The current stop reason determines which timer will -- be updated the next time TCP output stops. -- -- Since there is no explicit stop at the beginning of a -- timeout, it is necessary to retroactively reclassify the -- previous stop as 'Congestion Limited'. -- tcpEStatsPerfSndLimTransRwin OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of transitions into the 'Receiver Limited' state from either the 'Congestion Limited' or 'Sender Limited' states. This state is entered whenever TCP transmission stops because the sender has filled the announced receiver window." ::= { tcpEStatsPerfEntry 31 } tcpEStatsPerfSndLimTransCwnd OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of transitions into the 'Congestion Limited' state from either the 'Receiver Limited' or 'Sender Limited' states. This state is entered whenever TCP transmission stops because the sender has reached some limit defined by congestion control (e.g. cwnd) or other algorithms (retransmission timeouts) designed to control network traffic." ::= { tcpEStatsPerfEntry 32 } Mathis, et al [Page 27] Internet-Draft Expires April 23, 2006 Oct 23, 2005 tcpEStatsPerfSndLimTransSnd OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of transitions into the 'Sender Limited' state from either the 'Receiver Limited' or 'Congestion Limited' states. This state is entered whenever TCP transmission stops due to some sender limit such as running out of application data or other resources and the Karn algorithm. When TCP stops sending data for any reason which can not be classified as Receiver Limited or Congestion Limited it must be treated as Sender Limited." ::= { tcpEStatsPerfEntry 33 } tcpEStatsPerfSndLimTimeRwin OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The cumulative time (in milliseconds) spent in the 'Receiver Limited' state. See tcpEStatsPerfSndLimTransRwin." ::= { tcpEStatsPerfEntry 34 } tcpEStatsPerfSndLimTimeCwnd OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The cumulative time (in milliseconds) spent in the 'Congestion Limited' state. See tcpEStatsPerfSndLimTransCwnd. When there is a retransmission timeout, it should be counted in tcpEStatsPerfSndLimTimeCwnd (and not the cumulative time for some other state.)" ::= { tcpEStatsPerfEntry 35 } tcpEStatsPerfSndLimTimeSnd OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The cumulative time (in milliseconds) spent in the 'Sender Limited' state. See tcpEStatsPerfSndLimTransSnd." ::= { tcpEStatsPerfEntry 36 } -- ================================================================ -- Mathis, et al [Page 28] Internet-Draft Expires April 23, 2006 Oct 23, 2005 -- Statistics for diagnosing path problems -- tcpEStatsPathTable OBJECT-TYPE SYNTAX SEQUENCE OF TcpEStatsPathEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "This table contains objects that can be used to infer detailed behavior of the Internet path, such as the extent that there is reordering, ECN bits and if RTT fluctuations are correlated to losses." ::= { tcpEStats 3 } tcpEStatsPathEntry OBJECT-TYPE SYNTAX TcpEStatsPathEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "Each entry in this table has information about the characteristics of each active and recently closed tcp connection." INDEX { tcpEStatsConnectIndex } ::= { tcpEStatsPathTable 1 } TcpEStatsPathEntry ::= SEQUENCE { tcpEStatsPathRetranThresh Gauge32, tcpEStatsPathNonRecovDAEpisodes Integer32, tcpEStatsPathSumOctetsReordered Integer32, tcpEStatsPathNonRecovDA ZeroBasedCounter32, tcpEStatsPathSampleRTT Gauge32, tcpEStatsPathRTTVar Gauge32, tcpEStatsPathMaxRTT Gauge32, tcpEStatsPathMinRTT Gauge32, tcpEStatsPathSumRTT ZeroBasedCounter32, tcpEStatsPathHCSumRTT ZeroBasedCounter64, tcpEStatsPathCountRTT ZeroBasedCounter32, tcpEStatsPathMaxRTO Gauge32, tcpEStatsPathMinRTO Gauge32, tcpEStatsPathIpTtl Integer32, tcpEStatsPathIpTosIn Integer32, tcpEStatsPathIpTosOut Integer32, tcpEStatsPathPreCongSumCwnd ZeroBasedCounter32, tcpEStatsPathPreCongSumRTT ZeroBasedCounter32, tcpEStatsPathPostCongSumRTT ZeroBasedCounter32, tcpEStatsPathPostCongCountRTT ZeroBasedCounter32, tcpEStatsPathECNsignals ZeroBasedCounter32, Mathis, et al [Page 29] Internet-Draft Expires April 23, 2006 Oct 23, 2005 tcpEStatsPathECERcvd ZeroBasedCounter32, tcpEStatsPathQuenchRcvd ZeroBasedCounter32, tcpEStatsPathDupAckEpisodes ZeroBasedCounter32, tcpEStatsPathDupAcksOut ZeroBasedCounter32, tcpEStatsPathCERcvd ZeroBasedCounter32, tcpEStatsPathECNSent ZeroBasedCounter32, tcpEStatsPathECNNonceRcvd ZeroBasedCounter32 } -- -- The following optional objects can be used to infer segment -- reordering on the path from the local sender to the remote -- receiver. -- tcpEStatsPathRetranThresh OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of duplicate acknowledgments required to trigger Fast Retransmit. Note that although this is constant in traditional Reno TCP implementations, it is adaptive in many newer TCPs." ::= { tcpEStatsPathEntry 1 } tcpEStatsPathNonRecovDAEpisodes OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of duplicate acknowledgment episodes that did not trigger a Fast Retransmit because ACK advanced prior to the number of duplicate acknowledgments reaching RetranThresh. See [RFC2581]. In many implementations this is the number of times the 'dupacks' counter is set to zero when it is non-zero but less than RetranThresh. Note that tcpEStatsPathNonRecovDAEpisodes divided by tcpEStatsPerfDataSegsOut is an estimate of the frequency of data reordering on the forward path." ::= { tcpEStatsPathEntry 2 } tcpEStatsPathSumOctetsReordered OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-only Mathis, et al [Page 30] Internet-Draft Expires April 23, 2006 Oct 23, 2005 STATUS current DESCRIPTION "The sum of the amounts SND.UNA advances on the acknowledgment which ends a dup-ack episode without a retransmission. Note tcpEStatsPathSumOctetsReordered divided by tcpEStatsPathNonRecovDAEpisodes is an estimates of the average reordering distance, in octets." ::= { tcpEStatsPathEntry 3 } tcpEStatsPathNonRecovDA OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "Duplicate acks (or SACKS) that did not trigger a Fast Retransmit because ACK advanced prior to the number of duplicate acknowledgments reaching RetranThresh. In many implementations, this is the sum of the 'dupacks' counter, just before it is set to zero because ACK advanced without a Fast Retransmit. Note that tcpEStatsPathNonRecovDA divided by tcpEStatsPathNonRecovDAEpisodes is an estimate of the average reordering distance in segments." ::= { tcpEStatsPathEntry 4 } -- -- The following optional objects instrument the round trip -- time estimator and the retransmission timeout timer. See -- [RFC2988]. -- tcpEStatsPathSampleRTT OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The most recent raw round trip time measurement, in milliseconds, used in calculation of the RTO." ::= { tcpEStatsPathEntry 21 } tcpEStatsPathRTTVar OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current Mathis, et al [Page 31] Internet-Draft Expires April 23, 2006 Oct 23, 2005 DESCRIPTION "The round trip time variation, in milliseconds, used in calculation of the RTO. See RTTVAR in [RFC2988]." ::= { tcpEStatsPathEntry 22 } tcpEStatsPathMaxRTT OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The maximum sampled round trip time, in milliseconds." ::= { tcpEStatsPathEntry 23 } tcpEStatsPathMinRTT OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The minimum sampled round trip time, in milliseconds." ::= { tcpEStatsPathEntry 24 } tcpEStatsPathSumRTT OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The sum of all sampled round trip times, in milliseconds. Note that the change in tcpEStatsPathSumRTT divided by the change in tcpEStatsPathCountRTT is the mean RTT, uniformly averaged over an enter interval." ::= { tcpEStatsPathEntry 25 } tcpEStatsPathHCSumRTT OBJECT-TYPE SYNTAX ZeroBasedCounter64 MAX-ACCESS read-only STATUS current DESCRIPTION "The sum of all sampled round trip times, in milliseconds, on all systems that implement multiple concurrent RTT measurements. Note that the change in tcpEStatsPathHCSumRTT divided by the change in tcpEStatsPathCountRTT is the mean RTT, uniformly averaged over an enter interval." ::= { tcpEStatsPathEntry 26 } tcpEStatsPathCountRTT OBJECT-TYPE Mathis, et al [Page 32] Internet-Draft Expires April 23, 2006 Oct 23, 2005 SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of round trip time samples included in tcpEStatsPathSumRTT." ::= { tcpEStatsPathEntry 27 } tcpEStatsPathMaxRTO OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The maximum value of the retransmit timer RTO, in milliseconds. See [RFC2988]." ::= { tcpEStatsPathEntry 28 } tcpEStatsPathMinRTO OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The minimum value of the retransmit timer RTO, in milliseconds. See [RFC2988]." ::= { tcpEStatsPathEntry 29 } -- -- The following optional objects provide information about -- how TCP is using the IP layer. -- tcpEStatsPathIpTtl OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-only STATUS current DESCRIPTION "The value of the TTL field carried in the most recently received IP header. This is sometimes useful to detect changing or unstable routes." ::= { tcpEStatsPathEntry 30 } tcpEStatsPathIpTosIn OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-only STATUS current DESCRIPTION "The value of the IPv4 Type Of Service octet, or the IPv6 traffic class octet, carried in the most recently received Mathis, et al [Page 33] Internet-Draft Expires April 23, 2006 Oct 23, 2005 IP header. See [RFC2474] and [RFC3260]. This is useful to diagnose interactions between TCP and any IP layer packet scheduling and delivery policy, which might be in effect to implement QoS." ::= { tcpEStatsPathEntry 31 } tcpEStatsPathIpTosOut OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-only STATUS current DESCRIPTION "The value of the IPv4 Type Of Service octet, or the IPv6 traffic class octet, carried in the most recently transmitted IP header. See [RFC2474] and [RFC3260]. This is useful to diagnose interactions between TCP and any IP layer packet scheduling and delivery policy, which might be in effect to implement QoS." ::= { tcpEStatsPathEntry 32 } -- -- The following optional objects characterize the congestion -- feedback signals by collecting statistics on how the -- congestion events are correlated to losses, changes in RTT -- and other protocol events. -- tcpEStatsPathPreCongSumCwnd OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The sum of the values of the congestion window, in octets, captured each time a congestion signal is received. This MUST be updated each time tcpEStatsPerfCongSignals is incremented, such that the ratio is the average window at congestion." ::= { tcpEStatsPathEntry 33 } tcpEStatsPathPreCongSumRTT OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "Sum of the last sample of the RTT (tcpEStatsPathSampleRTT) prior to received congestion signals. This MUST be updated each time tcpEStatsPerfCongSignals is incremented, such Mathis, et al [Page 34] Internet-Draft Expires April 23, 2006 Oct 23, 2005 that the ratio is the average RTT just prior to congestion." ::= { tcpEStatsPathEntry 34 } tcpEStatsPathPostCongSumRTT OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "Sum of the first RTT sample following a received congestion signal." ::= { tcpEStatsPathEntry 35 } tcpEStatsPathPostCongCountRTT OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of RTT samples included in tcpEStatsPathPostCongSumRTT such that the ratio is average RTT just after congestion." ::= { tcpEStatsPathEntry 36 } -- -- The following optional objects can be used to detect other -- types of non-loss congestion signals such as source quench -- or ECN. -- tcpEStatsPathECNsignals OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of congestion signals delivered via all forms of explicit congestion notification including the ECE bit and failing the ECN nonce check, etc." ::= { tcpEStatsPathEntry 37 } tcpEStatsPathECERcvd OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of congestion signals received via the ECE bit [RFC3168]." ::= { tcpEStatsPathEntry 38 } tcpEStatsPathQuenchRcvd OBJECT-TYPE Mathis, et al [Page 35] Internet-Draft Expires April 23, 2006 Oct 23, 2005 SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of ICMP quench messages that are treated as congestion signals." ::= { tcpEStatsPathEntry 39 } -- -- The following optional objects are receiver side -- instruments of the path from the sender to the receiver. In -- general the receiver has less information about the state -- of the path, because the receiver does not have a robust -- mechanism to infer the sender's actions. -- tcpEStatsPathDupAckEpisodes OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of Duplicate Acks Sent when prior Ack was not duplicate. This is the number of times that a contiguous series of duplicate acknowledgments have been sent. This is an indication of the number of data segments lost or reordered on the path from the remote TCP endpoint to the near TCP endpoint." ::= { tcpEStatsPathEntry 40 } tcpEStatsPathDupAcksOut OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of duplicate ACKs sent. The ratio of tcpEStatsPathDupAcksOut to tcpEStatsPathDupAckEpisodes is an indication of reorder or recovery distance." ::= { tcpEStatsPathEntry 41 } tcpEStatsPathCERcvd OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "Received segments with Congestion Experienced bits. See [RFC3168]." ::= { tcpEStatsPathEntry 42 } Mathis, et al [Page 36] Internet-Draft Expires April 23, 2006 Oct 23, 2005 tcpEStatsPathECNSent OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "Number of times CE bits have set ECN. See [RFC3168]." ::= { tcpEStatsPathEntry 43 } tcpEStatsPathECNNonceRcvd OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "Number of ECN Nonces received. Note that the low bit is the same as the one bit nonce sum." ::= { tcpEStatsPathEntry 44 } -- ================================================================ -- -- Statistics for diagnosing stack algorithms -- tcpEStatsStackTable OBJECT-TYPE SYNTAX SEQUENCE OF TcpEStatsStackEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "This table contains objects that are most useful for determining how well some of the TCP control algorithms are coping with this particular path." ::= { tcpEStats 4 } tcpEStatsStackEntry OBJECT-TYPE SYNTAX TcpEStatsStackEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "Each entry in this table has information about the characteristics of each active and recently closed tcp connection." INDEX { tcpEStatsConnectIndex } ::= { tcpEStatsStackTable 1 } TcpEStatsStackEntry ::= SEQUENCE { tcpEStatsStackState INTEGER, tcpEStatsStackSACK TruthValue, Mathis, et al [Page 37] Internet-Draft Expires April 23, 2006 Oct 23, 2005 tcpEStatsStackTimeStamps TruthValue, tcpEStatsStackECN TruthValue, tcpEStatsStackNagle TruthValue, tcpEStatsStackSndWindScale Integer32, tcpEStatsStackRcvWindScale Integer32, tcpEStatsStackActiveOpen TruthValue, tcpEStatsStackMaxSsCwnd Gauge32, tcpEStatsStackMaxCaCwnd Gauge32, tcpEStatsStackMaxSsthresh Gauge32, tcpEStatsStackMinSsthresh Gauge32, tcpEStatsStackInRecovery INTEGER, tcpEStatsStackDupAcksIn ZeroBasedCounter32, tcpEStatsStackSpuriousFrDetected ZeroBasedCounter32, tcpEStatsStackSpuriousRtoDetected ZeroBasedCounter32, tcpEStatsStackMSSSent Unsigned32, tcpEStatsStackMSSRcvd Unsigned32, tcpEStatsStackWinScaleSent Integer32, tcpEStatsStackWinScaleRcvd Integer32, tcpEStatsStackSACKokSent TruthValue, tcpEStatsStackSACKokRcvd TruthValue, tcpEStatsStackTimeStampSent TruthValue, tcpEStatsStackTimeStampRcvd TruthValue, tcpEStatsStackSoftErrors ZeroBasedCounter32, tcpEStatsStackSoftErrorReason INTEGER, tcpEStatsStackSndInitial Counter32, tcpEStatsStackRecInitial Counter32, tcpEStatsStackSlowStart ZeroBasedCounter32, tcpEStatsStackCongAvoid ZeroBasedCounter32, tcpEStatsStackOtherReductions ZeroBasedCounter32, tcpEStatsStackCongOverCount ZeroBasedCounter32, tcpEStatsStackFastRetran ZeroBasedCounter32, tcpEStatsStackSubsequentTimeouts ZeroBasedCounter32, tcpEStatsStackCurTimeoutCount Gauge32, tcpEStatsStackAbruptTimeouts ZeroBasedCounter32, tcpEStatsStackSACKsRcvd ZeroBasedCounter32, tcpEStatsStackSACKBlocksRcvd ZeroBasedCounter32, tcpEStatsStackSendStall ZeroBasedCounter32, tcpEStatsStackDSACKDups ZeroBasedCounter32, tcpEStatsStackMaxMSS Gauge32, tcpEStatsStackMinMSS Gauge32, tcpEStatsStackCurRetxQueue Gauge32, tcpEStatsStackMaxRetxQueue Gauge32, tcpEStatsStackCurReasmQueue Gauge32, tcpEStatsStackMaxReasmQueue Gauge32 } -- -- The following objects indicate TCP state and if various Mathis, et al [Page 38] Internet-Draft Expires April 23, 2006 Oct 23, 2005 -- optional TCP features or algorithms are enabled. -- tcpEStatsStackState OBJECT-TYPE SYNTAX INTEGER { tcpESStateClosed(1), tcpESStateListen(2), tcpESStateSynSent(3), tcpESStateSynReceived(4), tcpESStateEstablished(5), tcpESStateFinWait1(6), tcpESStateFinWait2(7), tcpESStateCloseWait(8), tcpESStateLastAck(9), tcpESStateClosing(10), tcpESStateTimeWait(11), tcpESStateDeleteTcb(12) } MAX-ACCESS read-only STATUS current DESCRIPTION "An integer value representing the connection state from the TCP State Transition Diagram. See [RFC793]. The value listen(2) is included only for parallelism to the old tcpConnTable, and should not be used because the listen state in managed by the tcpListenerTable. The value DeleteTcb(12) is included only for parallelism to the tcpConnTable mechanism for terminating connections, although this table does not permit writing." ::= { tcpEStatsStackEntry 1 } tcpEStatsStackSACK OBJECT-TYPE SYNTAX TruthValue MAX-ACCESS read-only STATUS current DESCRIPTION "True(1) if SACK has been negotiated on, else false(2). See [RFC2018]." ::= { tcpEStatsStackEntry 2 } tcpEStatsStackTimeStamps OBJECT-TYPE SYNTAX TruthValue MAX-ACCESS read-only STATUS current DESCRIPTION "True(1) if timestamps have been negotiated on, else Mathis, et al [Page 39] Internet-Draft Expires April 23, 2006 Oct 23, 2005 false(2). See [RFC1323]." ::= { tcpEStatsStackEntry 3 } tcpEStatsStackECN OBJECT-TYPE SYNTAX TruthValue MAX-ACCESS read-only STATUS current DESCRIPTION "True(1) if ECN has been negotiated on, else false(2). See [RFC3168]." ::= { tcpEStatsStackEntry 4 } tcpEStatsStackNagle OBJECT-TYPE SYNTAX TruthValue MAX-ACCESS read-only STATUS current DESCRIPTION "True(1) if the Nagle algorithm is being used, else false(2). See [RFC896] and [RFC1122]." ::= { tcpEStatsStackEntry 5 } tcpEStatsStackSndWindScale OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-only STATUS current DESCRIPTION "The value of Snd.Wind.Scale from [RFC1323]. Note that tcpEStatsStackSndWindScale is either zero or the same as tcpEStatsStackWinScaleRcvd." ::= { tcpEStatsStackEntry 6 } tcpEStatsStackRcvWindScale OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-only STATUS current DESCRIPTION "The value of Rcv.Wind.Scale from [RFC1323]. Note that tcpEStatsStackRcvWindScale is either zero or the same as tcpEStatsStackWinScaleSent." ::= { tcpEStatsStackEntry 7 } tcpEStatsStackActiveOpen OBJECT-TYPE SYNTAX TruthValue MAX-ACCESS read-only STATUS current DESCRIPTION "True(1) if the local connection traversed the SYN-SENT state, else false(2). See [RFC793]." Mathis, et al [Page 40] Internet-Draft Expires April 23, 2006 Oct 23, 2005 ::= { tcpEStatsStackEntry 8 } -- -- The following objects instrument the overall operation of -- TCP congestion control and data retransmissions. These -- instruments are sufficient to fit the actual performance to -- an updated macroscopic performance model [RFC2581] [Mat97] -- [Pad98]. -- tcpEStatsStackMaxSsCwnd OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The maximum congestion window used during Slow Start, in octets." ::= { tcpEStatsStackEntry 9 } tcpEStatsStackMaxCaCwnd OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The maximum congestion window used during Congestion Avoidance, in octets." ::= { tcpEStatsStackEntry 10 } tcpEStatsStackMaxSsthresh OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The maximum slow start threshold, excluding the initial value." ::= { tcpEStatsStackEntry 11 } tcpEStatsStackMinSsthresh OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The minimum slow start threshold." ::= { tcpEStatsStackEntry 12 } tcpEStatsStackInRecovery OBJECT-TYPE SYNTAX INTEGER { tcpESDataContiguous(1), Mathis, et al [Page 41] Internet-Draft Expires April 23, 2006 Oct 23, 2005 tcpESDataUnordered(2), tcpESDataRecovery(3) } MAX-ACCESS read-only STATUS current DESCRIPTION "An integer value representing the state of the loss recovery for this connection. tcpESDataContiguous(1) indicates that the remote receiver is reporting contiguous data (no duplicate acknowledgments or SACK options) and that there are no unacknowledged retransmissions. tcpESDataUnordered(2) indicates that the remote receiver is reporting missing or out-of-order data (sending duplicate acknowledgments or SACK options) and that there are no unacknowledged retransmissions (because the missing data has not yet been retransmitted). tcpESDataRecovery(3) indicates that the sender has outstanding retransmitted data which is still in flight (i.e. is still unacknowledged). tcpEStatsStackInRecovery is a required precondition for some algorithms on other instruments. E.g. Some algorithms to estimate path properties may not be valid during recovery." ::= { tcpEStatsStackEntry 13 } tcpEStatsStackDupAcksIn OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of duplicate ACKs received." ::= { tcpEStatsStackEntry 14 } tcpEStatsStackSpuriousFrDetected OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of acknowledgments reporting out-of-order segments after the Fast Retransmit algorithm has already retransmitted the segments. (For example as detected by the Eiffle algorithm, [RFC3522]).'" ::= { tcpEStatsStackEntry 15 } Mathis, et al [Page 42] Internet-Draft Expires April 23, 2006 Oct 23, 2005 tcpEStatsStackSpuriousRtoDetected OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of acknowledgments reporting segments that have already be retransmitted due to a Retransmission Timeout." ::= { tcpEStatsStackEntry 16 } -- -- The following optional objects reflect the options -- requested on the SYN and/or SYN-ACK. These are useful for -- debugging problems with TCP option negotiation. -- tcpEStatsStackMSSSent OBJECT-TYPE SYNTAX Unsigned32 MAX-ACCESS read-only STATUS current DESCRIPTION "The value sent in an MSS option, or zero if none." ::= { tcpEStatsStackEntry 21 } tcpEStatsStackMSSRcvd OBJECT-TYPE SYNTAX Unsigned32 MAX-ACCESS read-only STATUS current DESCRIPTION "The value received in an MSS option, or zero if none." ::= { tcpEStatsStackEntry 22 } tcpEStatsStackWinScaleSent OBJECT-TYPE SYNTAX Integer32 (-1..14) MAX-ACCESS read-only STATUS current DESCRIPTION "The value of the transmitted window scale option if one was sent; otherwise, a value of -1. See [RFC1323]." ::= { tcpEStatsStackEntry 23 } tcpEStatsStackWinScaleRcvd OBJECT-TYPE SYNTAX Integer32 (-1..14) MAX-ACCESS read-only STATUS current DESCRIPTION "The value of the received window scale option if one was received; otherwise, a value of -1. See [RFC1323]." ::= { tcpEStatsStackEntry 24 } Mathis, et al [Page 43] Internet-Draft Expires April 23, 2006 Oct 23, 2005 tcpEStatsStackSACKokSent OBJECT-TYPE SYNTAX TruthValue MAX-ACCESS read-only STATUS current DESCRIPTION "True(1) if SACKok option was sent, else false(2). See [RFC2018]." ::= { tcpEStatsStackEntry 25 } tcpEStatsStackSACKokRcvd OBJECT-TYPE SYNTAX TruthValue MAX-ACCESS read-only STATUS current DESCRIPTION "True(1) if SACKok option was received, else false(2). See [RFC2018]." ::= { tcpEStatsStackEntry 26 } tcpEStatsStackTimeStampSent OBJECT-TYPE SYNTAX TruthValue MAX-ACCESS read-only STATUS current DESCRIPTION "True(1) if Timestamp option was sent, else false(2). See [RFC1323]." ::= { tcpEStatsStackEntry 27 } tcpEStatsStackTimeStampRcvd OBJECT-TYPE SYNTAX TruthValue MAX-ACCESS read-only STATUS current DESCRIPTION "True(1) if Timestamp option was received, else false(2). See [RFC1323]." ::= { tcpEStatsStackEntry 28 } -- -- The following optional objects instrument unusual protocol -- events that probably indicate implementation problems in -- the protocol or path. -- tcpEStatsStackSoftErrors OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of segments that fail various consistency tests Mathis, et al [Page 44] Internet-Draft Expires April 23, 2006 Oct 23, 2005 during TCP input processing. Soft errors might cause the segment to be discard but some do not. Some of these soft errors cause the generation of a TCP acknowledgment, others are silently discarded." ::= { tcpEStatsStackEntry 29 } tcpEStatsStackSoftErrorReason OBJECT-TYPE SYNTAX INTEGER { belowDataWindow(1), aboveDataWindow(2), belowAckWindow(3), aboveAckWindow(4), belowTSWindow(5), aboveTSWindow(6), dataCheckSum(7), otherSoftError(8) } MAX-ACCESS read-only STATUS current DESCRIPTION "This object identities which consistency test most recently failed during tcp input processing. This object should be set every time tcpEStatsStackSoftErrors is incremented. The codes are as follows: belowDataWindow - All data in the segment is below SND.UNA. (Normal for keep-alives and possibly zero window probes). aboveDataWindow - Some data in the segment is above SND.WND. (Indicates an implementation bug or serious fraud). belowAckWindow - ACK below SND.UNA. (Indicates that the return path is reordering ACKs) aboveAckWindow - An ACK for data that we have not sent. (Indicates an implementation bug or serious fraud). belowTSWindow - TSecr on the segment is older than the current TS.Recent [RFC1323] (Normal for the rare case where PAWS detects data reordered by the network.) aboveTSWindow - TSecr on the segment is newer than the current TS.Recent [RFC1323]. (Indicates an implementation bug or serious fraud). dataCheckSum - Incorrect checksum. Note that this value is intrinsically fragile, because the header fields used to Mathis, et al [Page 45] Internet-Draft Expires April 23, 2006 Oct 23, 2005 identify the connection may have been corrupted. otherSoftError - All other soft errors. Implementors are permitted to assign additional codes greater than 8 such that all SoftErrors in their implementation have unique codes. Management stations are to accumulate all unassigned codes as 'otherSoftErrors'" ::= { tcpEStatsStackEntry 30 } -- -- The following optional initial value objects are useful for -- conformance testing instruments on application progress and -- consumed network resources. -- tcpEStatsStackSndInitial OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "Initial send sequence number. Note that by definition tcpEStatsStackSndInitial never changes for a given connection. See [RFC793]." ::= { tcpEStatsStackEntry 31 } tcpEStatsStackRecInitial OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "Initial receive sequence number. Note that by definition tcpEStatsStackRecInitial never changes for a given connection. See [RFC793]." ::= { tcpEStatsStackEntry 32 } -- -- The following optional objects expose the detailed -- operation of the congestion control algorithms. -- tcpEStatsStackSlowStart OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of times the congestion window has been increased by the Slow Start algorithm. See [RFC2581]." Mathis, et al [Page 46] Internet-Draft Expires April 23, 2006 Oct 23, 2005 ::= { tcpEStatsStackEntry 33 } tcpEStatsStackCongAvoid OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of times the congestion window has been increased by the Congestion Avoidance algorithm. See [RFC2581]." ::= { tcpEStatsStackEntry 34 } tcpEStatsStackOtherReductions OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of congestion window reductions made as a result of anything other than AIMD congestion control algorithms. Examples of non-multiplicative window reductions include experimental algorithms such as Vegas [Bra94], and Congestion Window Validation [RFC2861]. All window reductions MUST be counted as either tcpEStatsPerfCongSignals or tcpEStatsStackOtherReductions." ::= { tcpEStatsStackEntry 35 } tcpEStatsStackCongOverCount OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of congestion events which were 'backed out' of the congestion control state machine such that the congestion window was restored to a prior value. This can happen due to the Eiffle algorithm [RFC3522] or other algorithms which can be used to detect and cancel spurious invocations of the Fast Retransmit Algorithm. Although it may be feasible to undo the effects of spurious invocation of the Fast Retransmit congestion events can not easily be backed out of tcpEStatsPerfCongSignals and tcpEStatsPathPreCongSumCwnd, etc." ::= { tcpEStatsStackEntry 36 } tcpEStatsStackFastRetran OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only Mathis, et al [Page 47] Internet-Draft Expires April 23, 2006 Oct 23, 2005 STATUS current DESCRIPTION "The number of invocations of the Fast Retransmit algorithm. See [RFC2581]." ::= { tcpEStatsStackEntry 37 } tcpEStatsStackSubsequentTimeouts OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of times the retransmit timeout has expired after the RTO has been doubled. See 5.5 of [RFC2988]." ::= { tcpEStatsStackEntry 38 } tcpEStatsStackCurTimeoutCount OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The current number of times the retransmit timeout has expired without receiving an acknowledgment for new data. tcpEStatsStackCurTimeoutCount is reset to zero when new data is acknowledged and incremented for each invocation of section 5.5 in [RFC2988]." ::= { tcpEStatsStackEntry 39 } tcpEStatsStackAbruptTimeouts OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of timeouts that occurred without any immediately preceding duplicate acknowledgments or other indications of congestion. Abrupt Timeouts indicate that the path lost an entire window of data or acknowledgments. Timeouts that are preceded by duplicate acknowledgments or other congestion signals (e.g. ECN) are not counted as abrupt, and might have been avoided by a more sophisticated Fast Retransmit algorithm." ::= { tcpEStatsStackEntry 40 } tcpEStatsStackSACKsRcvd OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION Mathis, et al [Page 48] Internet-Draft Expires April 23, 2006 Oct 23, 2005 "The number of SACK options received. See [RFC2018]." ::= { tcpEStatsStackEntry 41 } tcpEStatsStackSACKBlocksRcvd OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of SACK blocks received (within SACK options)." ::= { tcpEStatsStackEntry 42 } tcpEStatsStackSendStall OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of interface stalls or other sender local resource limitations that are treated as congestion signals." ::= { tcpEStatsStackEntry 43 } tcpEStatsStackDSACKDups OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of duplicate segments reported to the local host by D-SACK blocks. See [RFC2883]." ::= { tcpEStatsStackEntry 44 } -- -- The following optional objects instrument path MTU -- discovery. -- tcpEStatsStackMaxMSS OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The maximum MSS, in octets. See [RFC1191]." ::= { tcpEStatsStackEntry 45 } tcpEStatsStackMinMSS OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION Mathis, et al [Page 49] Internet-Draft Expires April 23, 2006 Oct 23, 2005 "The minimum MSS, in octets. See [RFC1191]." ::= { tcpEStatsStackEntry 46 } -- -- The following optional objects instrument the senders -- buffer usage, including any buffering in the application -- interface to TCP and the retransmit queue. All 'buffer -- memory' instruments are assumed to include OS data -- structure overhead. -- tcpEStatsStackCurRetxQueue OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The current number of octets of data occupying the retransmit queue." ::= { tcpEStatsStackEntry 47 } tcpEStatsStackMaxRetxQueue OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The maximum number of octets of data occupying the retransmit queue." ::= { tcpEStatsStackEntry 48 } tcpEStatsStackCurReasmQueue OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The current number of octets of sequence space spanned by the reassembly queue. This is generally the difference between rcv.nxt and the sequence number of the right most edge of the reassembly queue." ::= { tcpEStatsStackEntry 49 } tcpEStatsStackMaxReasmQueue OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The maximum value of tcpEStatsStackCurReasmQueue" ::= { tcpEStatsStackEntry 50 } Mathis, et al [Page 50] Internet-Draft Expires April 23, 2006 Oct 23, 2005 -- ================================================================ -- -- Statistics for diagnosing interactions between -- applications and TCP. -- tcpEStatsAppTable OBJECT-TYPE SYNTAX SEQUENCE OF TcpEStatsAppEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "This table contains objects that are useful for determining if the application using TCP is limiting TCP performance" ::= { tcpEStats 5 } tcpEStatsAppEntry OBJECT-TYPE SYNTAX TcpEStatsAppEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "Each entry in this table has information about the characteristics of each active and recently closed tcp connection." INDEX { tcpEStatsConnectIndex } ::= { tcpEStatsAppTable 1 } TcpEStatsAppEntry ::= SEQUENCE { tcpEStatsAppSndUna Counter32, tcpEStatsAppSndNxt Integer32, tcpEStatsAppSndMax Counter32, tcpEStatsAppThruOctetsAcked ZeroBasedCounter32, tcpEStatsAppHCThruOctetsAcked ZeroBasedCounter64, tcpEStatsAppRcvNxt Counter32, tcpEStatsAppThruOctetsReceived ZeroBasedCounter32, tcpEStatsAppHCThruOctetsReceived ZeroBasedCounter64, tcpEStatsAppCurAppWQueue Gauge32, tcpEStatsAppMaxAppWQueue Gauge32, tcpEStatsAppCurAppRQueue Gauge32, tcpEStatsAppMaxAppRQueue Gauge32 } -- -- The following objects provide throughput statistics for the -- connection including sequence numbers and elapsed -- application data. These permit direct observation of the -- applications progress, in terms of elapsed data delivery Mathis, et al [Page 51] Internet-Draft Expires April 23, 2006 Oct 23, 2005 -- and elapsed time. See [RFC793]. -- tcpEStatsAppSndUna OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The value of SND.UNA, the oldest unacknowledged sequence number." ::= { tcpEStatsAppEntry 1 } tcpEStatsAppSndNxt OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-only STATUS current DESCRIPTION "The value of SND.NXT, the next sequence number to be sent. Note that tcpEStatsAppSndNxt is not a monotonic (and thus not a counter) because TCP sometimes retransmits lost data by pulling tcpEStatsAppSndNxt back to the missing data." ::= { tcpEStatsAppEntry 2 } tcpEStatsAppSndMax OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The farthest forward (right most or largest) SND.NXT value. Note that this will be equal to tcpEStatsAppSndNxt except when tcpEStatsAppSndNxt is pulled back during recovery." ::= { tcpEStatsAppEntry 3 } tcpEStatsAppThruOctetsAcked OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of octets for which cumulative acknowledgments have been received. Note that this will be the sum of changes to tcpEStatsAppSndUna." ::= { tcpEStatsAppEntry 4 } tcpEStatsAppHCThruOctetsAcked OBJECT-TYPE SYNTAX ZeroBasedCounter64 MAX-ACCESS read-only STATUS current DESCRIPTION Mathis, et al [Page 52] Internet-Draft Expires April 23, 2006 Oct 23, 2005 "The number of octets for which cumulative acknowledgments have been received, on systems that can receive more than 10 million bits per second. Note that this will be the sum of changes in tcpEStatsAppSndUna." ::= { tcpEStatsAppEntry 5 } tcpEStatsAppRcvNxt OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The value of RCV.NXT from [RFC793]. The next sequence number expected on an incoming segment, and the left or lower edge of the receive window." ::= { tcpEStatsAppEntry 6 } tcpEStatsAppThruOctetsReceived OBJECT-TYPE SYNTAX ZeroBasedCounter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of octets for which cumulative acknowledgments have been sent. Note that this will be the sum of changes to tcpEStatsAppRcvNxt." ::= { tcpEStatsAppEntry 7 } tcpEStatsAppHCThruOctetsReceived OBJECT-TYPE SYNTAX ZeroBasedCounter64 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of octets for which cumulative acknowledgments have been sent, on systems that can transmit more than 10 million bits per second. Note that this will be the sum of changes in tcpEStatsAppRcvNxt." ::= { tcpEStatsAppEntry 8 } tcpEStatsAppCurAppWQueue OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The current number of octets of application data buffered by TCP, pending first transmission, i.e. to the left of SND.NXT or SndMax. This data will generally be transmitted (and SND.NXT advanced to the left) as soon as there is available congestion window (cwnd) or receiver window (rwin). This is the amount of data readily available for Mathis, et al [Page 53] Internet-Draft Expires April 23, 2006 Oct 23, 2005 transmission, without scheduling the application. TCP performance may suffer if there is insufficient queued write data." ::= { tcpEStatsAppEntry 21 } tcpEStatsAppMaxAppWQueue OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The maximum number of octets of application data buffered by TCP, pending first transmission. This is the maximum value of tcpEStatsAppCurAppWQueue. This pair of objects can be used to determine if insufficient queued data is steady state (suggesting insufficient queue space) or transient (suggesting insufficient application performance or excessive CPU load or scheduler latency)." ::= { tcpEStatsAppEntry 22 } tcpEStatsAppCurAppRQueue OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The current number of octets of application data that has been acknowledged by TCP but not yet delivered to the application." ::= { tcpEStatsAppEntry 23 } tcpEStatsAppMaxAppRQueue OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The maximum number of octets of application data that has been acknowledged by TCP but not yet delivered to the application." ::= { tcpEStatsAppEntry 24 } -- ================================================================ -- -- Controls for Tuning TCP -- tcpEStatsTuneTable OBJECT-TYPE SYNTAX SEQUENCE OF TcpEStatsTuneEntry MAX-ACCESS not-accessible STATUS current Mathis, et al [Page 54] Internet-Draft Expires April 23, 2006 Oct 23, 2005 DESCRIPTION "This table contains per connection controls that can be used to work around a number of common problems that plague TCP over some paths. All can be characterized as limiting the growth of the congestion window so as to prevent TCP from overwhelming some component in the path." ::= { tcpEStats 6 } tcpEStatsTuneEntry OBJECT-TYPE SYNTAX TcpEStatsTuneEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "Each entry in this table is a control that can be used to place limits on each active tcp connection." INDEX { tcpEStatsConnectIndex } ::= { tcpEStatsTuneTable 1 } TcpEStatsTuneEntry ::= SEQUENCE { tcpEStatsTuneLimCwnd Gauge32, tcpEStatsTuneLimSsthresh Gauge32, tcpEStatsTuneLimRwin Gauge32 } tcpEStatsTuneLimCwnd OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-write STATUS current DESCRIPTION "A control to set the maximum congestion window which may be used, in octets." ::= { tcpEStatsTuneEntry 1 } tcpEStatsTuneLimSsthresh OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-write STATUS current DESCRIPTION "A control to limit the maximum queue space (in octets) that this TCP connection is likely to occupy during slowstart. It can be implemented with the algorithm described in RFC3742 by setting the max_ssthresh parameter to twice tcpEStatsTuneLimSsthresh. This algorithm can be used to overcome some TCP performance problems over network paths that do not have sufficient Mathis, et al [Page 55] Internet-Draft Expires April 23, 2006 Oct 23, 2005 buffering to withstand the bursts normally present during slowstart." ::= { tcpEStatsTuneEntry 2 } tcpEStatsTuneLimRwin OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-write STATUS current DESCRIPTION "A control to set the maximum window advertisement which may be sent, in octets." ::= { tcpEStatsTuneEntry 3 } -- ================================================================ -- -- TCP Extended Statistics Notifications Group -- tcpEStatsEstablishNotification NOTIFICATION-TYPE OBJECTS { tcpEStatsConnectIndex } STATUS current DESCRIPTION "The indicated connection has been accepted (or alternatively entered the established state)." ::= { tcpEStatsNotifications 1 } tcpEStatsCloseNotification NOTIFICATION-TYPE OBJECTS { tcpEStatsConnectIndex } STATUS current DESCRIPTION "The indicated connection has left the established state" ::= { tcpEStatsNotifications 2 } -- ================================================================ -- -- Conformance Definitions -- tcpEStatsCompliances OBJECT IDENTIFIER ::= { tcpEStatsConformance 1 } tcpEStatsGroups OBJECT IDENTIFIER ::= { tcpEStatsConformance 2 } Mathis, et al [Page 56] Internet-Draft Expires April 23, 2006 Oct 23, 2005 -- -- Compliance Statements -- tcpEStatsCompliance MODULE-COMPLIANCE STATUS current DESCRIPTION "Compliance statement for all systems that implement TCP extended statistics." MODULE -- this module MANDATORY-GROUPS { tcpEStatsListenerGroup, tcpEStatsConnectIdGroup, tcpEStatsPerfGroup, tcpEStatsPathGroup, tcpEStatsStackGroup, tcpEStatsAppGroup } GROUP tcpEStatsListenerHCGroup DESCRIPTION "This group is mandatory for all systems that can wrap the values of the 32-bit counters in tcpEStatsListenerGroup in less than one hour." GROUP tcpEStatsPerfOptionalGroup DESCRIPTION "This group is optional for all systems." GROUP tcpEStatsPerfHCGroup DESCRIPTION "This group is mandatory for systems that can wrap the values of the 32-bit counters in tcpEStatsPerfGroup in less than one hour. Note that any system that can attain 10 Mb/s can potentially wrap 32-Bit Octet counters in under one hour." GROUP tcpEStatsPathOptionalGroup DESCRIPTION "This group is optional for all systems." GROUP tcpEStatsPathHCGroup DESCRIPTION "This group is mandatory for systems that can wrap the values of the 32-bit counters in tcpEStatsPathGroup in less than one hour. Mathis, et al [Page 57] Internet-Draft Expires April 23, 2006 Oct 23, 2005 Note that any system that can attain 10 Mb/s can potentially wrap 32-Bit Octet counters in under one hour." GROUP tcpEStatsStackOptionalGroup DESCRIPTION "This group is optional for all systems." GROUP tcpEStatsAppHCGroup DESCRIPTION "This group is mandatory for systems that can wrap the values of the 32-bit counters in tcpEStatsStackGroup in less than one hour. Note that any system that can attain 10 Mb/s can potentially wrap 32-Bit Octet counters in under one hour." GROUP tcpEStatsAppOptionalGroup DESCRIPTION "This group is optional for all systems." GROUP tcpEStatsTuneOptionalGroup DESCRIPTION "This group is optional for all systems." GROUP tcpEStatsNotificationsGroup DESCRIPTION "This group is optional for all systems." GROUP tcpEStatsNotificationsCtlGroup DESCRIPTION "This group is mandatory for systems that include the tcpEStatsNotificationGroup." OBJECT tcpEStatsControlNotify MIN-ACCESS read-only DESCRIPTION "Write access is not required." ::= { tcpEStatsCompliances 1 } -- ================================================================ -- -- Units of Conformance -- tcpEStatsListenerGroup OBJECT-GROUP OBJECTS { Mathis, et al [Page 58] Internet-Draft Expires April 23, 2006 Oct 23, 2005 tcpEStatsListenerTableLastChange, tcpEStatsListenerStartTime, tcpEStatsListenerSynRcvd, tcpEStatsListenerInitial, tcpEStatsListenerEstablished, tcpEStatsListenerAccepted, tcpEStatsListenerExceedBacklog, tcpEStatsListenerCurrConns, tcpEStatsListenerMaxBacklog, tcpEStatsListenerCurBacklog, tcpEStatsListenerCurEstabBacklog } STATUS current DESCRIPTION "The tcpEStatsListener group includes objects that provide valuable statistics and debugging information for TCP Listeners." ::= { tcpEStatsGroups 1 } tcpEStatsListenerHCGroup OBJECT-GROUP OBJECTS { tcpEStatsListenerHCSynRcvd, tcpEStatsListenerHCInitial, tcpEStatsListenerHCEstablished, tcpEStatsListenerHCAccepted, tcpEStatsListenerHCExceedBacklog } STATUS current DESCRIPTION "The tcpEStatsListenerHC group includes 64 bit counters in tcpEStatsListenerTable." ::= { tcpEStatsGroups 2 } tcpEStatsConnectIdGroup OBJECT-GROUP OBJECTS { tcpEStatsConnTableLatency, tcpEStatsConnectIndex } STATUS current DESCRIPTION "The tcpEStatsConnectId group includes objects that identify TCP connections and control how long TCP connection entries are retained in the tables." ::= { tcpEStatsGroups 3 } tcpEStatsPerfGroup OBJECT-GROUP OBJECTS { tcpEStatsPerfSegsOut, tcpEStatsPerfDataSegsOut, Mathis, et al [Page 59] Internet-Draft Expires April 23, 2006 Oct 23, 2005 tcpEStatsPerfDataOctetsOut, tcpEStatsPerfSegsRetrans, tcpEStatsPerfOctetsRetrans, tcpEStatsPerfSegsIn, tcpEStatsPerfDataSegsIn, tcpEStatsPerfDataOctetsIn, tcpEStatsPerfElapsedSecs, tcpEStatsPerfElapsedMicroSecs, tcpEStatsPerfStartTimeStamp, tcpEStatsPerfCurMSS, tcpEStatsPerfPipeSize, tcpEStatsPerfMaxPipeSize, tcpEStatsPerfSmoothedRTT, tcpEStatsPerfCurRTO, tcpEStatsPerfCongSignals, tcpEStatsPerfCurCwnd, tcpEStatsPerfCurSsthresh, tcpEStatsPerfTimeouts, tcpEStatsPerfCurRwinSent, tcpEStatsPerfMaxRwinSent, tcpEStatsPerfZeroRwinSent, tcpEStatsPerfCurRwinRcvd, tcpEStatsPerfMaxRwinRcvd, tcpEStatsPerfZeroRwinRcvd } STATUS current DESCRIPTION "The tcpEStatsPerf group includes those objects that provide basic performance data for a TCP connection." ::= { tcpEStatsGroups 4 } tcpEStatsPerfOptionalGroup OBJECT-GROUP OBJECTS { tcpEStatsPerfSndLimTransRwin, tcpEStatsPerfSndLimTransCwnd, tcpEStatsPerfSndLimTransSnd, tcpEStatsPerfSndLimTimeRwin, tcpEStatsPerfSndLimTimeCwnd, tcpEStatsPerfSndLimTimeSnd } STATUS current DESCRIPTION "The tcpEStatsPerf group includes those objects that provide basic performance data for a TCP connection." ::= { tcpEStatsGroups 5 } tcpEStatsPerfHCGroup OBJECT-GROUP OBJECTS { tcpEStatsPerfHCDataOctetsOut, tcpEStatsPerfHCDataOctetsIn } STATUS current DESCRIPTION "The tcpEStatsPerfHC group includes 64 bit Mathis, et al [Page 60] Internet-Draft Expires April 23, 2006 Oct 23, 2005 counters in the tcpEStatsPerfTable." ::= { tcpEStatsGroups 6 } tcpEStatsPathGroup OBJECT-GROUP OBJECTS { tcpEStatsControlPath, tcpEStatsPathRetranThresh, tcpEStatsPathNonRecovDAEpisodes, tcpEStatsPathSumOctetsReordered, tcpEStatsPathNonRecovDA } STATUS current DESCRIPTION "The tcpEStatsPath group includes objects that control the creation of the tcpEStatsPathTable, and provide information about the path for each TCP connection." ::= { tcpEStatsGroups 7 } tcpEStatsPathOptionalGroup OBJECT-GROUP OBJECTS { tcpEStatsPathSampleRTT, tcpEStatsPathRTTVar, tcpEStatsPathMaxRTT, tcpEStatsPathMinRTT, tcpEStatsPathSumRTT, tcpEStatsPathCountRTT, tcpEStatsPathMaxRTO, tcpEStatsPathMinRTO, tcpEStatsPathIpTtl, tcpEStatsPathIpTosIn, tcpEStatsPathIpTosOut, tcpEStatsPathPreCongSumCwnd, tcpEStatsPathPreCongSumRTT, tcpEStatsPathPostCongSumRTT, tcpEStatsPathPostCongCountRTT, tcpEStatsPathECNsignals, tcpEStatsPathECERcvd, tcpEStatsPathQuenchRcvd, tcpEStatsPathDupAckEpisodes, tcpEStatsPathDupAcksOut, tcpEStatsPathCERcvd, tcpEStatsPathECNSent, tcpEStatsPathECNNonceRcvd } STATUS current DESCRIPTION "The tcpEStatsPath group includes objects that provide additional information about the path for each TCP connection." ::= { tcpEStatsGroups 8 } tcpEStatsPathHCGroup OBJECT-GROUP OBJECTS { tcpEStatsPathHCSumRTT Mathis, et al [Page 61] Internet-Draft Expires April 23, 2006 Oct 23, 2005 } STATUS current DESCRIPTION "The tcpEStatsPathHC group includes 64 bit counters in the tcpEStatsPathTable." ::= { tcpEStatsGroups 9 } tcpEStatsStackGroup OBJECT-GROUP OBJECTS { tcpEStatsControlStack, tcpEStatsStackState, tcpEStatsStackSACK, tcpEStatsStackTimeStamps, tcpEStatsStackECN, tcpEStatsStackNagle, tcpEStatsStackSndWindScale, tcpEStatsStackRcvWindScale, tcpEStatsStackActiveOpen, tcpEStatsStackMaxSsCwnd, tcpEStatsStackMaxCaCwnd, tcpEStatsStackMaxSsthresh, tcpEStatsStackMinSsthresh, tcpEStatsStackInRecovery, tcpEStatsStackDupAcksIn, tcpEStatsStackSpuriousFrDetected, tcpEStatsStackSpuriousRtoDetected } STATUS current DESCRIPTION "The tcpEStatsConnState group includes objects that control the creation of the tcpEStatsStackTable, and provide information about the operation of algorithms used within TCP." ::= { tcpEStatsGroups 10 } tcpEStatsStackOptionalGroup OBJECT-GROUP OBJECTS { tcpEStatsStackMSSSent, tcpEStatsStackMSSRcvd, tcpEStatsStackWinScaleSent, tcpEStatsStackWinScaleRcvd, tcpEStatsStackSACKokSent, tcpEStatsStackSACKokRcvd, tcpEStatsStackTimeStampSent, tcpEStatsStackTimeStampRcvd, tcpEStatsStackSoftErrors, tcpEStatsStackSoftErrorReason, tcpEStatsStackSndInitial, tcpEStatsStackRecInitial, tcpEStatsStackSlowStart, tcpEStatsStackCongAvoid, tcpEStatsStackOtherReductions, tcpEStatsStackCongOverCount, tcpEStatsStackFastRetran, tcpEStatsStackSubsequentTimeouts, Mathis, et al [Page 62] Internet-Draft Expires April 23, 2006 Oct 23, 2005 tcpEStatsStackCurTimeoutCount, tcpEStatsStackAbruptTimeouts, tcpEStatsStackSACKsRcvd, tcpEStatsStackSACKBlocksRcvd, tcpEStatsStackSendStall, tcpEStatsStackDSACKDups, tcpEStatsStackMaxMSS, tcpEStatsStackMinMSS, tcpEStatsStackCurRetxQueue, tcpEStatsStackMaxRetxQueue, tcpEStatsStackCurReasmQueue, tcpEStatsStackMaxReasmQueue } STATUS current DESCRIPTION "The tcpEStatsConnState group includes objects that provide additional information about the operation of algorithms used within TCP." ::= { tcpEStatsGroups 11 } tcpEStatsAppGroup OBJECT-GROUP OBJECTS { tcpEStatsControlApp, tcpEStatsAppSndUna, tcpEStatsAppSndNxt, tcpEStatsAppSndMax, tcpEStatsAppThruOctetsAcked, tcpEStatsAppRcvNxt, tcpEStatsAppThruOctetsReceived } STATUS current DESCRIPTION "The tcpEStatsConnState group includes objects that control the creation of the tcpEStatsAppTable, and provide information about the operation of algorithms used within TCP." ::= { tcpEStatsGroups 12 } tcpEStatsAppHCGroup OBJECT-GROUP OBJECTS { tcpEStatsAppHCThruOctetsAcked, tcpEStatsAppHCThruOctetsReceived } STATUS current DESCRIPTION "The tcpEStatsStackHC group includes 64 bit counters in the tcpEStatsStackTable." ::= { tcpEStatsGroups 13 } tcpEStatsAppOptionalGroup OBJECT-GROUP OBJECTS { tcpEStatsAppCurAppWQueue, Mathis, et al [Page 63] Internet-Draft Expires April 23, 2006 Oct 23, 2005 tcpEStatsAppMaxAppWQueue, tcpEStatsAppCurAppRQueue, tcpEStatsAppMaxAppRQueue } STATUS current DESCRIPTION "The tcpEStatsConnState group includes objects that provide additional information about how applications are interacting with each TCP connection." ::= { tcpEStatsGroups 14 } tcpEStatsTuneOptionalGroup OBJECT-GROUP OBJECTS { tcpEStatsControlTune, tcpEStatsTuneLimCwnd, tcpEStatsTuneLimSsthresh, tcpEStatsTuneLimRwin } STATUS current DESCRIPTION "The tcpEStatsConnState group includes objects that control the creation of the tcpEStatsConnectionTable, which can be used to set tuning parameters for each TCP connection." ::= { tcpEStatsGroups 15 } tcpEStatsNotificationsGroup NOTIFICATION-GROUP NOTIFICATIONS { tcpEStatsEstablishNotification, tcpEStatsCloseNotification } STATUS current DESCRIPTION "Notifications sent by a TCP extended statistics agent." ::= { tcpEStatsGroups 16 } tcpEStatsNotificationsCtlGroup OBJECT-GROUP OBJECTS { tcpEStatsControlNotify } STATUS current DESCRIPTION "The tcpEStatsNotificationsCtl group includes the object that controls the creation of the events in the tcpEStatsNotificationsGroup." ::= { tcpEStatsGroups 17 } END Mathis, et al [Page 64] Internet-Draft Expires April 23, 2006 Oct 23, 2005 5. Normative References [RFC2574] U. Blumenthal, B. Wijnen, "User-based Security Model (USM) for version 3 of the Simple Network Management Protocol (SNMPv3)", RFC2574, April 1999. [RFC2575] Wijnen, B., Presuhn, R., and K. McCloghrie, "View-based Access Control Model (VACM) for the Simple Network Management Protocol (SNMP)", RFC 2575, April 1999. [RFC2578] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M., and S. Waldbusser, "Structure of Management Information Version 2 (SMIv2)", STD 58, RFC 2578, April 1999. [RFC2579] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M., and S. Waldbusser, "Textual Conventions for SMIv2", STD 58, RFC 2579, April 1999. [RFC2580] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M., and S. Waldbusser, "Conformance Statements for SMIv2", STD 58, RFC 2580, April 1999. [RFC4022] Raghunarayan, R., "Management Information Base for the Trans- mission Control Protocol (TCP)", RFC 4022, March 2005. 6. Informative References [Mat97] M. Mathis, J. Semke, J. Mahdavi, T. Ott, "The Macroscopic Behav- ior of the TCP Congestion Avoidance Algorithm", Computer Communica- tion Review, volume 27, number3, July 1997. [Bra94] Brakmo, L., O'Malley, S., "TCP Vegas, New Techniques for Conges- tion Detection and Avoidance," SIGCOMM'94, London, pp 24-35, Octo- ber 1994. [POSIX] Portable Operating System Interface, IEEE Std 1003.1 Mathis, et al [Page 65] Internet-Draft Expires April 23, 2006 Oct 23, 2005 [Pad98] Padhye, J., Firoiu, V., Towsley, D., Kurose, J., "Modeling TCP Throughput: A Simple Model and its Empirical Validation", SIG- COMM'98 [Web100] Mathis, M., J. Heffner, R. Reddy, "Web100: Extended TCP Instru- mentation for Research, Education and Diagnosis", ACM Computer Com- munications Review, Vol 33, Num 3, July 2003. [RFC793] J. Postel Ed., "Transmission Control Protocol", Sep 1981. [RFC896] J. Nagle, "Congestion control in IP/TCP internetworks", Jan-06-1984. [RFC1122] R. Braden, Ed, "Requirements for Internet Hosts - Communica- tion Layers", October 1989. [RFC1191] J.C. Mogul, S.E. Deering, "Path MTU discovery", Nov-01-1990. [RFC1323] V. Jacobson, R. Braden, D. Borman, "TCP Extensions for High Performance", May 1992. [RFC2018] M. Mathis, J. Mahdavi, S. Floyd, A. Romanow, "TCP Selective Acknowledgment Options", October 1996. [RFC2021] S. Waldbusser, "Remote Network Monitoring Management Informa- tion Base Version 2 using SMIv2", January 1997. [RFC2474] K. Nichols, S. Blake, F. Baker, D. Black, "Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Head- ers", December 1998. [RFC2856] A. Bierman, K. McCloghrie, R. Presuhn, "Textual Conventions for Additional High Capacity Data Types", June 2000. [RFC2861] M. Handley, J. Padhye, S. Floyd, "TCP Congestion Window Vali- dation", June 2000. Mathis, et al [Page 66] Internet-Draft Expires April 23, 2006 Oct 23, 2005 [RFC2883] S. Floyd, J. Mahdavi, M. Mathis, M. Podolsky, "An Extension to the Selective Acknowledgment (SACK) Option for TCP", July 2000. [RFC3168] K. Ramakrishnan, S. Floyd, D. Black, "The Addition of Explicit Congestion Notification (ECN) to IP", September 2001. [RFC3260] D. Grossman, "New Terminology and Clarifications for Diff- serv", April 2002. [RFC3410] Case, J., Mundy, R., Partain, D. and B. Stewart, "Introduction and Applicability Statements for Internet-Standard Management Framework", RFC 3410, December 2002. [RFC3522] R. Ludwig, M. Meyer, "The Eifel Detection Algorithm for TCP", April 2003. [RFC2581] M. Allman, V. Paxson, W. Stevens, "TCP Congestion Control", April 1999. [RFC2988] V. Paxson, M. Allman, "Computing TCP's Retransmission Timer", November 2000. [RFC3291] M. Daniele, B. Haberman, S. Routhier, J. Schoenwaelder, "Tex- tual Conventions for Internet Network Addresses", May 2002. [RFC4001] Daniele, M., Haberman, B., Routhier, S., and J. Schoenwaelder, "Textual Conventions for Internet Network Addresses", RFC 3291, May 2002. 7. Security Considerations There are a number of management objects defined in this MIB that have a MAX-ACCESS clause of read-write and/or read-create. Such objects may be considered sensitive or vulnerable in some network environments. The support for SET operations in a non-secure environment without proper protection can have a negative effect on Mathis, et al [Page 67] Internet-Draft Expires April 23, 2006 Oct 23, 2005 network operations. There are a number of managed objects in this MIB that may contain sensitive information. These are: tcpEStatsConnectRemAddress tcpEStatsAppSndUna tcpEStatsAppSndNxt tcpEStatsAppSndMax tcpEStatsStackSndInitial tcpEStatsAppRcvNxt tcpEStatsStackRecInitial It is thus important to control even GET access to these objects and possibly to even encrypt the values of these objects when sending them over the network via SNMP. Not all versions of SNMP provide features for such a secure environment. SNMPv1 by itself is not a secure environment. Even if the network itself is secure (for example by using IPSec) there is no control as to who on the secure network is allowed to access and GET/SET (read/change/create/delete) the objects in this MIB. It is recommended that implementers consider using the security features as provided by the SNMPv3 framework. Specifically, the use of the User-based Security Model RFC 2574 [RFC2574] and the View- based Access Control Model RFC 2575 [RFC2575] is recommended. It is then a customer/user responsibility to ensure that the SNMP entity giving access to an instance of this MIB, is properly configured to only give access to the objects to those principals (users) that have legitimate rights to indeed GET or SET (change/create/delete) them. 8. Contributors The following people contributed text that was incorporated into this document: Jon Saperia converted Web100 internal documentation into a true MIB. Jon can be reached at JDS Consulting, Inc, 617-744-1079. Some of the objects in this document were moved from an early draft of the TCP-MIB, by Bill Fenner et al. Some of the object descriptions are based on an earlier unpublished document by Jeff Semke. Mathis, et al [Page 68] Internet-Draft Expires April 23, 2006 Oct 23, 2005 9. Acknowledgments This document is a product of the Web100 project (www.web100.org), a joint effort of the Pittsburgh Supercomputing Center (www.psc.edu), National Center for Atmospheric Research (www.ncar.ucar.edu) and National Center for Supercomputer Applications (www.ncsa.edu). It would not have been possible without all of the hard work by the the entire Web100 team, especially Peter O'Neal who read and reread the entire document several times; Janet Brown and Marla Meehl, who patiently managed the unmanageable. The Web100 project would not have been successful without all of the early adopters who suffered our bugs to provide many good suggestions and insights into their needs for TCP instrumentation. Web100 was supported by the National Science Foundation under Grant No. 0083285 and a research grant from Cisco Systems. We would also like to thank all of the people who built experimental implementations of this MIB from early versions of the Internet Draft and provided us with constructive feedback: Glenn Turner at AARnet, Kristine Adamson at IBM and Xinyan Zan at Microsoft. 10. Authors' Addresses Matt Mathis John Heffner Pittsburgh Supercomputing Center 4400 Fifth Ave Pittsburgh, PA 15216 Phone: 412-268-4960 Email: mathis@web100.org, rreddy@psc.edu, jheffner@psc.edu Rajiv Raghunarayan Cisco Systems Inc. San Jose, CA 95134 Phone: 408 853 9612 Email: raraghun@cisco.com 11. Intellectual Property The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it Mathis, et al [Page 69] Internet-Draft Expires April 23, 2006 Oct 23, 2005 represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. 12. Disclaimer of Validity This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 13. Copyright Statement Copyright (C) The Internet Society (2005). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. Mathis, et al [Page 70]