Network Working Group G. Mirsky Internet-Draft X. Min Updates: 8762 (if approved) ZTE Corp. Intended status: Standards Track H. Nydell Expires: December 24, 2020 Accedian Networks R. Foote Nokia A. Masputra Apple Inc. E. Ruffini OutSys June 22, 2020 Simple Two-way Active Measurement Protocol Optional Extensions draft-ietf-ippm-stamp-option-tlv-06 Abstract This document describes optional extensions to Simple Two-way Active Measurement Protocol (STAMP) which enable measurement performance metrics in addition to ones supported by the STAMP base specification. The document also defines a STAMP Test Session Identifier and thus updates RFC 8762. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. 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." This Internet-Draft will expire on December 24, 2020. Copyright Notice Copyright (c) 2020 IETF Trust and the persons identified as the document authors. All rights reserved. Mirsky, et al. Expires December 24, 2020 [Page 1] Internet-Draft STAMP Extensions June 2020 This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Conventions Used in This Document . . . . . . . . . . . . . . 3 2.1. Acronyms . . . . . . . . . . . . . . . . . . . . . . . . 3 2.2. Requirements Language . . . . . . . . . . . . . . . . . . 3 3. STAMP Test Session Identifier . . . . . . . . . . . . . . . . 4 4. TLV Extensions to STAMP . . . . . . . . . . . . . . . . . . . 8 4.1. Extra Padding TLV . . . . . . . . . . . . . . . . . . . . 9 4.2. Location TLV . . . . . . . . . . . . . . . . . . . . . . 10 4.3. Timestamp Information TLV . . . . . . . . . . . . . . . . 11 4.4. Class of Service TLV . . . . . . . . . . . . . . . . . . 12 4.5. Direct Measurement TLV . . . . . . . . . . . . . . . . . 14 4.6. Access Report TLV . . . . . . . . . . . . . . . . . . . . 15 4.7. Follow-up Telemetry TLV . . . . . . . . . . . . . . . . . 16 4.8. HMAC TLV . . . . . . . . . . . . . . . . . . . . . . . . 18 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19 5.1. STAMP TLV Registry . . . . . . . . . . . . . . . . . . . 19 5.2. Synchronization Source Sub-registry . . . . . . . . . . . 20 5.3. Timestamping Method Sub-registry . . . . . . . . . . . . 20 5.4. Return Code Sub-registry . . . . . . . . . . . . . . . . 21 6. Security Considerations . . . . . . . . . . . . . . . . . . . 22 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 22 8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 22 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 22 9.1. Normative References . . . . . . . . . . . . . . . . . . 22 9.2. Informative References . . . . . . . . . . . . . . . . . 23 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 24 1. Introduction Simple Two-way Active Measurement Protocol (STAMP) [RFC8762] supports the use of optional extensions that use Type-Length-Value (TLV) encoding. Such extensions enhance the STAMP base functions, such as measurement of one-way and round-trip delay, latency, packet loss, and the ability to detect packet duplication and out-of- order delivery of the test packets. This specification defines optional STAMP extensions, their formats, and the theory of operation. Also, Mirsky, et al. Expires December 24, 2020 [Page 2] Internet-Draft STAMP Extensions June 2020 a STAMP Test Session Identifier is defined as an update of the base STAMP specification [RFC8762]. 2. Conventions Used in This Document 2.1. Acronyms STAMP Simple Two-way Active Measurement Protocol DSCP Differentiated Services Code Point ECN Explicit Congestion Notification NTP Network Time Protocol PTP Precision Time Protocol HMAC Hashed Message Authentication Code TLV Type-Length-Value BITS Building Integrated Timing Supply SSU Synchronization Supply Unit GPS Global Positioning System GLONASS Global Orbiting Navigation Satellite System LORAN-C Long Range Navigation System Version C MBZ Must Be Zero CoS Class of Service PMF Performance Measurement Function SSID STAMP Session Identifier 2.2. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. Mirsky, et al. Expires December 24, 2020 [Page 3] Internet-Draft STAMP Extensions June 2020 3. STAMP Test Session Identifier STAMP Session-Sender transmits test packets to STAMP Session- Reflector. STAMP Session-Reflector receives Session-Sender's packet and acts according to the configuration and optional control information communicated in the Session-Sender's test packet. STAMP defines two different test packet formats, one for packets transmitted by the STAMP-Session-Sender and one for packets transmitted by the STAMP-Session-Reflector. STAMP supports two modes: unauthenticated and authenticated. Unauthenticated STAMP test packets are compatible on the wire with unauthenticated TWAMP-Test [RFC5357] packet formats. By default, STAMP uses symmetrical packets, i.e., the size of the packet transmitted by Session-Reflector equals the size of the packet received by the Session-Reflector. A STAMP Session is identified using 4-tuple (source and destination IP addresses, source and destination UDP port numbers). A STAMP Session-Sender MAY generate a locally unique STAMP Session Identifier (SSID). SSID is two octets long non-zero unsigned integer. A Session-Sender MAY use SSID to identify a STAMP test session. If SSID is used, it MUST be present in each test packet of the given test session. In the unauthenticated mode, SSID is located, as displayed in Figure 1. Mirsky, et al. Expires December 24, 2020 [Page 4] Internet-Draft STAMP Extensions June 2020 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sequence Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Timestamp | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Error Estimate | SSID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | | | | MBZ (28 octets) | | | | | | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ Value ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1: An example of an extended STAMP Session-Sender test packet format in unauthenticated mode An implementation of STAMP Session-Reflector that supports this specification SHOULD identify a STAMP Session using the SSID in combination with elements of the usual 4-tuple for the session. Before a test session commences, a Session-Reflector MUST be provisioned with all the elements that identify the STAMP Session. A STAMP Session-Reflector MUST discard the non-matching STAMP test packet(s). The means of provisioning the STAMP Session identification is outside the scope of this specification. A conforming implementation of STAMP Session-Reflector MUST copy the SSID value from the received test packet and put it into the reflected packet, as displayed in Figure 2. Mirsky, et al. Expires December 24, 2020 [Page 5] Internet-Draft STAMP Extensions June 2020 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sequence Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Timestamp | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Error Estimate | SSID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Receive Timestamp | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Session-Sender Sequence Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Session-Sender Timestamp | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Session-Sender Error Estimate | MBZ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Ses-Sender TTL | MBZ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ Value ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2: An example of an extended STAMP Session-Reflector test packet format in unauthenticated mode A STAMP Session-Reflector that does not support this specification, will return the zeroed SSID field in the reflected STAMP test packet. The Session-Sender MAY stop the session if it receives a zeroed SSID field. An implementation of a Session-Sender MUST support control of its behavior in such a scenario. If the test session is not stopped, the Session-Sender, can, for example, send a base STAMP packet [RFC8762]. In the authenticated mode, location of SSID field is shown in Figure 3 and Figure 4. Mirsky, et al. Expires December 24, 2020 [Page 6] Internet-Draft STAMP Extensions June 2020 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sequence Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | | MBZ (12 octets) | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Timestamp | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Error Estimate | SSID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ ~ | MBZ (68 octets) | ~ ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | | HMAC (16 octets) | | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 3: Base STAMP Session-Sender test packet format in authenticated mode 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sequence Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MBZ (12 octets) | | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Timestamp | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Error Estimate | SSID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MBZ (4 octets) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Receive Timestamp | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MBZ (8 octets) | | | Mirsky, et al. Expires December 24, 2020 [Page 7] Internet-Draft STAMP Extensions June 2020 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Session-Sender Sequence Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MBZ (12 octets) | | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Session-Sender Timestamp | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Session-Sender Error Estimate | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | MBZ (6 octets) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Ses-Sender TTL | | +-+-+-+-+-+-+-+-+ + | | | MBZ (15 octets) | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | HMAC (16 octets) | | | | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 4: Base STAMP Session-Reflector test packet format in authenticated mode 4. TLV Extensions to STAMP Type-Length-Value (TLV) encoding scheme provides a flexible extension mechanism for optional informational elements. TLV is an optional field in the STAMP test packet. Multiple TLVs MAY be placed in the STAMP test packet. A TLV MAY be enclosed in a TLV. TLVs have the two octets long Type field, two octets long Length field that is equal to the length of the Value field in octets. If a Type value for TLV or sub-TLV is in the range for Vendor Private Use, the Length MUST be at least 4, and the first four octets MUST be that vendor's the Structure of Management Information (SMI) Private Enterprise Codes, as recorded in IANA's SMI Private Enterprise Codes sub- registry, in network octet order. The rest of the Value field is private to the vendor. The following sections describe the use of TLVs for STAMP that extend STAMP capability beyond its base specification. Mirsky, et al. Expires December 24, 2020 [Page 8] Internet-Draft STAMP Extensions June 2020 A STAMP node, whether Session-Sender or Session-Reflector, receiving a test packet MUST determine whether the packet is a base STAMP packet or includes one or more TLVs. The node MUST compare the value in the Length field of the UDP header and the length of the base STAMP test packet in the mode, unauthenticated or authenticated based on the configuration of the particular STAMP test session. If the difference between the two values is larger than the length of UDP header, then the test packet includes one or more STAMP TLVs that immediately follow the base STAMP test packet. A system that has received a STAMP test packet with extension TLVs MUST validate each TLV: if an implementation does not recognize the value in the Type field it MUST include the Extra Padding TLV into the reflected STAMP packet. The Length field MUST be set equal to the value of the Length field of that TLV. The size of the Value field MUST equal the value of the Length field. Then proceed to process the next TLV if any present; fixed-size TLVs are verified that the Length field value equals the value defined for the particular type. If the values are not equal, the processing of extension TLVs MUST be stopped. Also, if the system is the Session-Reflector, it MUST send the ICMP Parameter Problem message with Code set to 0 and the Pointer referring to the Length field of the TLV. Detected error events MUST be logged. Note that transmission of ICMP Error messages and logging SHOULD be throttled. 4.1. Extra Padding TLV 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extra Padding Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ Extra Padding ~ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 5: Extra Padding TLV where fields are defined as the following: o Extra Padding Type - TBA1 allocated by IANA Section 5.1 Mirsky, et al. Expires December 24, 2020 [Page 9] Internet-Draft STAMP Extensions June 2020 o Length - two octets long field equals length on the Extra Padding field in octets. o Extra Padding - a pseudo-random sequence of numbers. The field MAY be filled with all zeros. The Extra Padding TLV is similar to the Packet Padding field in TWAMP-Test packet [RFC5357]. The use of the Extra Padding TLV is RECOMMENDED to perform STAMP test using test packets of larger size than the base STAMP packet [RFC8762]. The length of the base STAMP is 44 octets in the unauthenticated mode or 112 octets in the authenticated mode. The Extra Padding TLV MAY be present more than one time in an extended STAMP test packet. 4.2. Location TLV STAMP Session-Sender MAY include the Location TLV to request information from the Session-Reflector. The Session-Sender SHOULD NOT fill any information fields except for Type and Length. The Session-Reflector MUST validate the Length value against the address family of the transport encapsulating the STAMP test packet. If the Length field's value is invalid, the Session-Reflector MUST zero all fields and MUST NOT return any information to the Session-Sender. The Session-Reflector MUST ignore all other fields of the received Location TLV. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Location Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Source MAC | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ Destination IP Address ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ Source IP Address ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Destination Port | Source Port | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 6: Session-Reflector Location TLV where fields are defined as the following: o Location Type - TBA2 allocated by IANA Section 5.1 Mirsky, et al. Expires December 24, 2020 [Page 10] Internet-Draft STAMP Extensions June 2020 o Length - two octets long field equals the length of the Value field in octets. The Length field value MUST equal 20 octets for the IPv4 address family. For the IPv6 address family, the value of the Length field MUST equal 44 octets. All other values are invalid. o Source MAC - 6 octets 48 bits long field. The Session-Reflector MUST copy Source MAC of received STAMP packet into this field. o Reserved - two octets long field. MUST be zeroed on transmission and ignored on reception. o Destination IP Address - IPv4 or IPv6 destination address of the packet received by the STAMP Session-Reflector. o Source IP Address - IPv4 or IPv6 source address of the packet received by the STAMP Session-Reflector. o Destination Port - two octets long UDP destination port number of the received STAMP packet. o Source Port - two octets long UDP source port number of the received STAMP packet. The Location TLV MAY be used to determine the last-hop IP addresses, ports, and last-hop MAC address for STAMP packets. The MAC address can indicate a path switch on the last hop The IP addresses and UDP port will indicate if there is a NAT router on the path, and allows the Session-Sender to identify the IP address of the Session- Reflector behind the NAT, detect changes in the NAT mapping that could cause sending the STAMP packets to the wrong Session-Reflector. 4.3. Timestamp Information TLV STAMP Session-Sender MAY include the Timestamp Information TLV to request information from the Session-Reflector. The Session-Sender SHOULD NOT fill any information fields except for Type and Length. The Session-Reflector MUST validate the Length value of the STAMP test packet. If the value of the Length field is invalid, the Session-Reflector MUST zero all fields and MUST NOT return any information to the Session-Sender. Mirsky, et al. Expires December 24, 2020 [Page 11] Internet-Draft STAMP Extensions June 2020 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Timestamp Information Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sync. Src In | Timestamp In | Sync. Src Out | Timestamp Out | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 7: Timestamp Information TLV where fields are defined as the following: o Timestamp Information Type - TBA3 allocated by IANA Section 5.1 o Length - two octets long field, set equal to the value 4. o Sync Src In - one octet long field that characterizes the source of clock synchronization at the ingress of Session-Reflector. There are several methods to synchronize the clock, e.g., Network Time Protocol (NTP) [RFC5905]. The value is one of those listed in Table 4. o Timestamp In - one octet long field that characterizes the method by which the ingress of Session-Reflector obtained the timestamp T2. A timestamp may be obtained with hardware assistance, via software API from a local wall clock, or from a remote clock (the latter is referred to as "control plane"). The value is one of those listed in Table 6. o Sync Src Out - one octet long field that characterizes the source of clock synchronization at the egress of Session-Reflector. The value is one of those listed in Table 4. o Timestamp Out - one octet long field that characterizes the method by which the egress of Session-Reflector obtained the timestamp T3. The value is one of those listed in Table 6. 4.4. Class of Service TLV The STAMP Session-Sender MAY include Class of Service (CoS) TLV in the STAMP test packet. The format of the CoS TLV is presented in Figure 8. Mirsky, et al. Expires December 24, 2020 [Page 12] Internet-Draft STAMP Extensions June 2020 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Class of Service Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | DSCP1 | DSCP2 |ECN| Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 8: Class of Service TLV where fields are defined as the following: o Class of Service Type - TBA4 allocated by IANA Section 5.1 o Length - two octets long field, set equal to the value 4. o DSCP1 - The Differentiated Services Code Point (DSCP) intended by the Session-Sender to be used as the DSCP value of the reflected by the Session-Reflector test packet. o DSCP2 - The received value in the DSCP field at the Session- Reflector in the forward direction. o ECN - The received value in the ECN field at the Session-Reflector in the forward direction. o Reserved - 18 bits long field, must be zeroed in transmission and ignored on receipt. A STAMP Session-Reflector that received the test packet with the CoS TLV MUST include the CoS TLV in the reflected test packet. Also, the Session-Reflector MUST copy the value of the DSCP and ECN fields of the IP header of the received STAMP test packet into the DSCP2 field in the reflected test packet. Finally, the Session-Reflector MUST set the DSCP field's value in the IP header of the reflected test packet equal to the value of the DSCP1 field of the received test packet. Upon receiving the reflected packet, the Session-Sender will save the DSCP and ECN values for analysis of the CoS in the reverse direction. Re-mapping of CoS can be used to provide multiple services (e,g., 2G, 3G, LTE in mobile backhaul networks) over the same network. But if it is misconfigured, then it is often difficult to diagnose the root cause of excessive packet drops of higher-level service while packet drops for lower service packets are at a normal level. Using CoS TLV in STAMP testing helps to troubleshoot the existing problem and also verify whether DiffServ policies are processing CoS as required by the configuration. Mirsky, et al. Expires December 24, 2020 [Page 13] Internet-Draft STAMP Extensions June 2020 4.5. Direct Measurement TLV The Direct Measurement TLV enables collection of "in profile" packets that had been transmitted and received by the Session-Sender and Session-Reflector respectfully. The definition of "in-profile packet" is outside the scope of this document and is left to the test operators to determine. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Direct Measurement Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Session-Sender Tx counter (S_TxC) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Session-Reflector Rx counter (R_RxC) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Session-Reflector Tx counter (R_TxC) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 9: Direct Measurement TLV where fields are defined as the following: o Direct Measurement Type - TBA5 allocated by IANA Section 5.1 o Length - two octets long field equals length on the Value field in octets. Length field value MUST equal 12 octets. o Session-Sender Tx counter (S_TxC) is four octets long field. o Session-Reflector Rx counter (R_RxC) is four octets long field. MUST be zeroed by the Session-Sender and filled by the Session- Reflector. o Session-Reflector Tx counter (R_TxC) is four octets long field. MUST be zeroed by the Session-Sender and filled by the Session- Reflector. A Session-Sender MAY include the Direct Measurement TLV in a STAMP test packet. The Session-Sender MUST zero R_RxC and R_TxC fields before the transmission of the STAMP test packet. If the received STAMP test packet includes the Direct Measurement TLV, the Session- Reflector MUST include it in the reflected test packet. The Session- Reflector MUST copy the value from the S_TxC field of the received test packet into the same field of the reflected packet before its transmission. Mirsky, et al. Expires December 24, 2020 [Page 14] Internet-Draft STAMP Extensions June 2020 4.6. Access Report TLV A STAMP Session-Sender MAY include Access Report TLV (Figure 10) to indicate changes to the access network status to the Session- Reflector. The definition of an access network is outside the scope of this document. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Access Report Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ID | Resv | Return Code | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 10: Access Report TLV where fields are defined as follows: o Access Report Type - TBA6 allocated by IANA Section 5.1. o Length - two octets long field, set equal to the value 4. o ID (Access ID) - four bits long field that identifies the access network, e.g., 3GPP (Radio Access Technologies specified by 3GPP) or Non-3GPP (accesses that are not specified by 3GPP) [TS23501]. The value is one of those listed below: * 1 - 3GPP Network * 2 - Non-3GPP Network All other values are invalid and the TLV that contains it MUST be discarded. o Resv - four bits long field, must be zeroed on transmission and ignored on receipt. o Return Code - one octet long field that identifies the report signal, e.g., available, unavailable. The value is passed, supplied to the STAMP end-point through some mechanism that is outside the scope of this document. The value is one of those listed in Section 5.4. o Reserved - two octets long field, must be zeroed on transmission and ignored on receipt. Mirsky, et al. Expires December 24, 2020 [Page 15] Internet-Draft STAMP Extensions June 2020 The STAMP Session-Sender that includes the Access Report TLV sets the value of the Access ID field according to the type of access network it reports on. Also, the Session-Sender sets the value of the Return Code field to reflect the operational state of the access network. The mechanism to determine the state of the access network is outside the scope of this specification. A STAMP Session-Reflector that received the test packet with the Access Report TLV MUST include the Access Report TLV in the reflected test packet. The Session- Reflector MUST set the value of the Access ID and Return Code fields equal to the values of the corresponding fields from the test packet it has received. The Session-Sender MUST also arm a retransmission timer after sending a test packet that includes the Access Report TLV. This timer MUST be disarmed upon the reception of the reflected STAMP test packet that includes Access Report TLV. In the event the timer expires before such a packet is received, the Session-Sender MUST retransmit the STAMP test packet that contains the Access Report TLV. This retransmission SHOULD be repeated up to four times before the procedure is aborted. Setting the value for the retransmission timer is based on local policies, network environment. The default value of the retransmission timer for Access Report TLV SHOULD be three seconds. An implementation MUST provide control of the retransmission timer value and the number of retransmissions. The Access Report TLV is used by the Performance Measurement Function (PMF) components of the Access Steering, Switching and Splitting feature for 5G networks [TS23501]. The PMF component in the User Equipment acts as the STAMP Session-Sender, and the PMF component in the User Plane Function acts as the STAMP Session-Reflector. 4.7. Follow-up Telemetry TLV A Session-Reflector might be able to put in the Timestamp field only an "SW Local" (see Table 6) timestamp. But the hosting system might provide the timestamp closer to the start of the actual packet transmission even though when it is not possible to deliver the information to the Session-Sender in the packet itself. This timestamp might nevertheless be important for the Session-Sender, as it improves the accuracy of measuring network delay by minimizing the impact of egress queuing delays on the measurement. A STAMP Session-Sender MAY include the Follow-up Telemetry TLV to request information from the Session-Reflector. The Session-Sender MUST set the Follow-up Telemetry Type and Length fields to their appropriate values. Sequence Number and Timestamp fields MUST be zeroed on transmission by the Session-Sender and ignored by the Session-Reflector upon receipt of the STAMP test packet that includes Mirsky, et al. Expires December 24, 2020 [Page 16] Internet-Draft STAMP Extensions June 2020 the Follow-up Telemetry TLV. The Session-Reflector MUST validate the Length value of the STAMP test packet. If the value of the Length field is invalid, the Session-Reflector MUST zero Sequence Number and Timestamp fields. If the Session-Reflector is in stateless mode (defined in Section 4.2 [RFC8762]), it MUST zero Sequence Number and Timestamp fields. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Follow-up Telemetry Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sequence Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Follow-up Timestamp | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Timestamp M | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 11: Follow-up Telemetry TLV where fields are defined as follows: o Follow-up Telemetry Type - TBA7 allocated by IANA Section 5.1. o Length - two octets long field, set equal to the value 16 octets. o Sequence Number - four octets long field indicating the sequence number of the last packet reflected in the same STAMP-test session. Since the Session-Reflector runs in the stateful mode (defined in Section 4.2 [RFC8762]), it is the Session-Reflector's Sequence Number of the previous reflected packet. o Follow-up Timestamp - eight octets long field, with the format indicated by the Z flag of the Error Estimate field of the packet transmitted by a Session-Reflector, as described in Section 4.1 [RFC8762]. It carries the timestamp when the reflected packet with the specified sequence number was sent. o Timestamp M(ode) - one octet long field that characterizes the method by which the entity that transmits a reflected STAMP packet obtained the Follow-up Timestamp. The value is one of those listed in Table 6. o Reserved - the three octets-long field. Its value MUST be zeroed on transmission and ignored on receipt. Mirsky, et al. Expires December 24, 2020 [Page 17] Internet-Draft STAMP Extensions June 2020 4.8. HMAC TLV The STAMP authenticated mode protects the integrity of data collected in the STAMP base packet. STAMP extensions are designed to provide valuable information about the condition of a network, and protecting the integrity of that data is also essential. The keyed Hashed Message Authentication Code (HMAC) TLV MUST be included in a STAMP test packet in the authenticated mode, excluding when the only TLV present is Extra Padding TLV. The HMAC TLV MUST follow all TLVs included in a STAMP test packet, except for the Extra Padding TLV. The HMAC TLV MAY be used to protect the integrity of STAMP extensions in STAMP unauthenticated mode. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | HMAC Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | | HMAC | | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 12: HMAC TLV where fields are defined as follows: o HMAC Type - is two octets long field, value TBA8 allocated by IANA Section 5.1. o Length - two octets long field, set equal to the value 16 octets. o HMAC - is 16 octets long field that carries HMAC digest of the text of all preceding TLVs. As defined in [RFC8762], STAMP uses HMAC-SHA-256 truncated to 128 bits ([RFC4868]). All considerations regarding using the key and key distribution and management listed in Section 4.4 of [RFC8762] are fully applicable to the use of the HMAC TLV. HMAC is calculated as defined in [RFC2104] over text as the concatenation of all preceding TLVs. The digest then MUST be truncated to 128 bits and written into the HMAC field. In the authenticated mode, HMAC MUST be verified before using any data in the included STAMP TLVs. If HMAC verification by the Session-Reflector fails, then an ICMP Parameter Problem message MUST be generated (with consideration of limiting the rate of error messages). The Code value MUST be set to 0 and the Pointer identifying HMAC Type. Also, both Session-Sender and Mirsky, et al. Expires December 24, 2020 [Page 18] Internet-Draft STAMP Extensions June 2020 Session-Reflector SHOULD log the notification that HMAC verification of STAMP TLVs failed. The packet that failed HMAC verification MUST be dropped. 5. IANA Considerations 5.1. STAMP TLV Registry IANA is requested to create the STAMP TLV Type registry. All code points in the range 1 through 32759 in this registry shall be allocated according to the "IETF Review" procedure as specified in [RFC8126]. Code points in the range 32760 through 65279 in this registry shall be allocated according to the "First Come First Served" procedure as specified in [RFC8126]. Remaining code points are allocated according to Table 1: +---------------+---------------------------------+---------------+ | Value | Description | Reference | +---------------+---------------------------------+---------------+ | 0 | Reserved | This document | | 1- 65279 | STAMP extension TLV, unassigned | IETF Review | | 65280 - 65519 | Experimental | This document | | 65520 - 65534 | Private Use | This document | | 65535 | Reserved | This document | +---------------+---------------------------------+---------------+ Table 1: STAMP TLV Type Registry This document defines the following new values in the STAMP Extension TLV range of the STAMP TLV Type registry: +-------+-----------------------+---------------+ | Value | Description | Reference | +-------+-----------------------+---------------+ | TBA1 | Extra Padding | This document | | TBA2 | Location | This document | | TBA3 | Timestamp Information | This document | | TBA4 | Class of Service | This document | | TBA5 | Direct Measurement | This document | | TBA6 | Access Report | This document | | TBA7 | Follow-up Telemetry | This document | | TBA8 | HMAC | This document | +-------+-----------------------+---------------+ Table 2: STAMP Types Mirsky, et al. Expires December 24, 2020 [Page 19] Internet-Draft STAMP Extensions June 2020 5.2. Synchronization Source Sub-registry IANA is requested to create Synchronization Source sub-registry as part of the STAMP TLV Type registry. All code points in the range 1 through 127 in this registry shall be allocated according to the "IETF Review" procedure as specified in [RFC8126]. Code points in the range 128 through 239 in this registry shall be allocated according to the "First Come First Served" procedure as specified in [RFC8126]. Remaining code points are allocated according to Table 1: +-----------+--------------+-------------------------+ | Value | Description | Reference | +-----------+--------------+-------------------------+ | 0 | Reserved | This document | | 1- 127 | Unassigned | IETF Review | | 128 - 239 | Unassigned | First Come First Served | | 240 - 249 | Experimental | This document | | 250 - 254 | Private Use | This document | | 255 | Reserved | This document | +-----------+--------------+-------------------------+ Table 3: Synchronization Source Sub-registry This document defines the following new values in the Synchronization Source sub-registry: +-------+---------------------+---------------+ | Value | Description | Reference | +-------+---------------------+---------------+ | 1 | NTP | This document | | 2 | PTP | This document | | 3 | SSU/BITS | This document | | 4 | GPS/GLONASS/LORAN-C | This document | | 5 | Local free-running | This document | +-------+---------------------+---------------+ Table 4: Synchronization Sources 5.3. Timestamping Method Sub-registry IANA is requested to create Timestamping Method sub-registry as part of the STAMP TLV Type registry. All code points in the range 1 through 127 in this registry shall be allocated according to the "IETF Review" procedure as specified in [RFC8126]. Code points in the range 128 through 239 in this registry shall be allocated according to the "First Come First Served" procedure as specified in [RFC8126]. Remaining code points are allocated according to Table 1: Mirsky, et al. Expires December 24, 2020 [Page 20] Internet-Draft STAMP Extensions June 2020 +-----------+--------------+-------------------------+ | Value | Description | Reference | +-----------+--------------+-------------------------+ | 0 | Reserved | This document | | 1- 127 | Unassigned | IETF Review | | 128 - 239 | Unassigned | First Come First Served | | 240 - 249 | Experimental | This document | | 250 - 254 | Private Use | This document | | 255 | Reserved | This document | +-----------+--------------+-------------------------+ Table 5: Timestamping Method Sub-registry This document defines the following new values in the Timestamping Methods sub-registry: +-------+---------------+---------------+ | Value | Description | Reference | +-------+---------------+---------------+ | 1 | HW Assist | This document | | 2 | SW local | This document | | 3 | Control plane | This document | +-------+---------------+---------------+ Table 6: Timestamping Methods 5.4. Return Code Sub-registry IANA is requested to create Return Code sub-registry as part of STAMP TLV Type registry. All code points in the range 1 through 127 in this registry shall be allocated according to the "IETF Review" procedure as specified in [RFC8126]. Code points in the range 128 through 239 in this registry shall be allocated according to the "First Come First Served" procedure as specified in [RFC8126]. Remaining code points are allocated according to Table 7: +-----------+--------------+-------------------------+ | Value | Description | Reference | +-----------+--------------+-------------------------+ | 0 | Reserved | This document | | 1- 127 | Unassigned | IETF Review | | 128 - 239 | Unassigned | First Come First Served | | 240 - 249 | Experimental | This document | | 250 - 254 | Private Use | This document | | 255 | Reserved | This document | +-----------+--------------+-------------------------+ Table 7: Return Code Sub-registry Mirsky, et al. Expires December 24, 2020 [Page 21] Internet-Draft STAMP Extensions June 2020 This document defines the following new values in the Return Code sub-registry: +-------+---------------------+---------------+ | Value | Description | Reference | +-------+---------------------+---------------+ | 1 | Network available | This document | | 2 | Network unavailable | This document | +-------+---------------------+---------------+ Table 8: Return Codes 6. Security Considerations This document defines extensions to STAMP [RFC8762] and inherits all the security considerations applicable to the base protocol. Additionally, the HMAC TLV is defined in this document to protect the integrity of optional STAMP extensions. The use of HMAC TLV is discussed in detail in Section 4.8. 7. Acknowledgments Authors much appreciate the thorough review and thoughtful comments received from Tianran Zhou, Rakesh Gandhi, Yuezhong Song and Yali Wang. Authors express their gratitude to Al Morton for his comments and the most valuable suggestions. Authors greatly appreciate comments and thoughtful suggestions received from Martin Duke. 8. Contributors The following people contributed text to this document: Guo Jun ZTE Corporation 68# Zijinghua Road Nanjing, Jiangsu 210012 P.R.China Phone: +86 18105183663 Email: guo.jun2@zte.com.cn 9. References 9.1. Normative References Mirsky, et al. Expires December 24, 2020 [Page 22] Internet-Draft STAMP Extensions June 2020 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC5357] Hedayat, K., Krzanowski, R., Morton, A., Yum, K., and J. Babiarz, "A Two-Way Active Measurement Protocol (TWAMP)", RFC 5357, DOI 10.17487/RFC5357, October 2008, . [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 8126, DOI 10.17487/RFC8126, June 2017, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC8762] Mirsky, G., Jun, G., Nydell, H., and R. Foote, "Simple Two-Way Active Measurement Protocol", RFC 8762, DOI 10.17487/RFC8762, March 2020, . 9.2. Informative References [RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed- Hashing for Message Authentication", RFC 2104, DOI 10.17487/RFC2104, February 1997, . [RFC4868] Kelly, S. and S. Frankel, "Using HMAC-SHA-256, HMAC-SHA- 384, and HMAC-SHA-512 with IPsec", RFC 4868, DOI 10.17487/RFC4868, May 2007, . [RFC5905] Mills, D., Martin, J., Ed., Burbank, J., and W. Kasch, "Network Time Protocol Version 4: Protocol and Algorithms Specification", RFC 5905, DOI 10.17487/RFC5905, June 2010, . [TS23501] 3GPP (3rd Generation Partnership Project), "Technical Specification Group Services and System Aspects; System Architecture for the 5G System; Stage 2 (Release 16)", 3GPP TS23501, 2019. Mirsky, et al. Expires December 24, 2020 [Page 23] Internet-Draft STAMP Extensions June 2020 Authors' Addresses Greg Mirsky ZTE Corp. Email: gregimirsky@gmail.com Xiao Min ZTE Corp. Email: xiao.min2@zte.com.cn Henrik Nydell Accedian Networks Email: hnydell@accedian.com Richard Foote Nokia Email: footer.foote@nokia.com Adi Masputra Apple Inc. One Apple Park Way Cupertino, CA 95014 USA Email: adi@apple.com Ernesto Ruffini OutSys via Caracciolo, 65 Milano 20155 Italy Email: eruffini@outsys.org Mirsky, et al. Expires December 24, 2020 [Page 24]