Network Working Group Thomas D. Nadeau Internet Draft Cisco Systems, Inc. Category: Informational Expires: August 2003 Cheenu Srinivasan Parama Networks, Inc. Adrian Farrel Movaz Networks, Inc. February 2003 Multiprotocol Label Switching (MPLS) Management Overview draft-ietf-mpls-mgmt-overview-03.txt Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC 2026 [RFC2026]. 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. Abstract A range of management Information Bases (MIBs) has been developed to help model and manage the various aspects of Multiprotocol Label Switching (MPLS) networks. These MIBs are defined in separate drafts and RFCs that focus on the specific areas of responsibility of their MIBs. This memo describes the management architecture for MPLS and indicates the inter-relationships between the different MIBs used for MPLS network management. Nadeau, Srinivasan and Farrel [Page 1] Internet Draft draft-ietf-mpls-mgmt-overview-03.txt February 2003 Table of Contents 1. Introduction 3 2. Terminology 3 3. The SNMP Management Framework 4 4. An Introduction to the MPLS Working Group MIB Modules 4 4.1. Structure of the MPLS MIB OID Tree 5 4.2. MPLS-TC-MIB 5 4.3. MPLS-LSR-MIB 6 4.4. MPLS-LDP-MIB 6 4.5. MPLS-LDP-GENERIC-MIB 6 4.6. MPLS-LDP-ATM-MIB 7 4.7. MPLS-LDP-FRAME-RELAY-MIB 7 4.8. MPLS-TE-MIB 7 4.9. MPLS-FTN-MIB 7 4.10. MPLS-LINK-BUNDLING-MIB 8 4.11. MIB Interdependencies 8 4.12. Dependencies on External MIBs 9 5. Tables, Scalars and Notifications in MPLS-LSR-MIB 9 5.1. Tables 9 5.2. Scalars 10 5.3. Notifications 10 5.4. Dependencies Between MIB Module Tables 10 6. Tables, Scalars and Notifications in the LDP MIB 11 6.1. MIB Modules 11 6.2. Tables 11 6.3. Scalars 12 6.4. Notifications 13 6.5. Dependencies Between MIB Module Tables 13 7. Tables, Scalars and Notifications in MPLS-TE-MIB 14 7.1. Tables 14 7.2. Scalars 15 7.3. Notifications 15 7.4. Dependencies Between MIB Module Tables 15 8. Tables, Scalars and Notifications in MPLS-FTN-MIB 16 8.1. Tables 16 8.2. Scalars 16 8.3. Notifications 16 8.4. Dependencies Between MIB Tables 16 9. Tables and Objects in MPLS-LINK-BUNDLING-MIB 16 9.1. Tables 16 9.2. Scalars 17 9.3. Notifications 17 9.4. Dependencies Between MIB Module Tables 17 10. MIB Table Dependencies Between MPLS MIBs 18 11. A Note on Interfaces 18 11.1. MPLS Tunnels as Interfaces 19 11.2. Application of the Interfaces Group to TE Links 19 11.3. References to Interface MIB Objects from Other MPLS MIBs 20 12. Management Options 21 13. Related IETF MIB Modules 22 13.1. pwe3 Working Group MIB Modules 22 13.2. ppvpn Working Group MIB Modules 23 13.2.1. PPVPN-MPLS-VPN-MIB 23 13.3. ccamp Working Group MIBs 23 14. Traffic Engineering Working Group TE MIB 23 14.1. Choosing Between TE MIBs Modules 24 Nadeau, Srinivasan and Farrel [Page 2] Internet Draft draft-ietf-mpls-mgmt-overview-03.txt February 2003 15. Security Considerations 24 16. Acknowledgements 24 17. Intellectual Property Consideration 25 18. Normative References 25 19. Informative References 26 20. Authors' Addresses 28 21. Full Copyright Statement 29 1. Introduction This memo describes the Management Architecture for Multi- Protocol Label Switching (MPLS) [RFC3031]. In particular, it describes how the managed objects defined in various MPLS related Management Information Base (MIB) documents model different aspects of MPLS. Furthermore, this document explains the interactions and dependencies between each of these MIBs. For additional information, this draft also includes a brief note on MIBs produced by the Pseudo Wire Emulation Edge to Edge (pwe3), Provider Provisioned Virtual Private Network (ppvpn), Common Control and Measurement Plane (ccamp), and Internet Traffic Engineering (tewg) working groups. The draft begins with a brief outline of the SNMP framework. This is not intended to be a complete reference on SNMP, but is provided to give context to the rest of the draft and to indicate reference material for readers that need to know more about SNMP. This draft does not propose any additions to the MPLS MIB framework, nor define any standards for the Internet community. It is an informational draft. In all cases, the reader is advised to turn to the draft or RFC that defines the MIB in question for further information. Comments should be made directly to the MPLS mailing list at mpls@uu.net. 2. Terminology This document uses terminology from the MPLS architecture document [RFC3031] and the following MPLS related MIBs: MPLS TC MIB [TCMIB], MPLS LSR MIB [LSRMIB], MPLS TE MIB [TEMIB], MPLS LDP MIB [LDPMIB], MPLS FTN MIB [FTNMIB], MPLS LINK BUNDLING MIB [LBMIB], and PPVPN MPLS VPN MIB [VPNMIB]. Throughout this document hyphenated MIB names (such as MPLS- TE-MIB) should be taken to refer to specific MIB modules. Non-hyphenated MIB names (such as MPLS LDP MIB) indicate MIB documents. Nadeau, Srinivasan and Farrel [Page 3] Internet Draft draft-ietf-mpls-mgmt-overview-03.txt February 2003 3. The SNMP Management Framework The SNMP Management Framework presently consists of five major components: - An overall architecture, described in RFC 2571 [RFC2571]. - Mechanisms for describing and naming objects and events for the purpose of management. The first version of this Structure of Management Information (SMI) is called SMIv1 and described in STD 16, RFC 1155 [RFC1155], STD 16, RFC 1212 [RFC1212] and STD 16, RFC 1215 [RFC1215]. The second version, called SMIv2, is described in STD 58, RFC 2578 [RFC2578], STD 58, RFC 2579 [RFC2579] and STD 58, RFC 2580 [RFC2580]. - Message protocols for transferring management information. The first version of the SNMP message protocol is called SNMPv1 and described in STD 15, RFC 1157 [RFC1157]. A second version of the SNMP message protocol, which is not an Internet standards track protocol, is called SNMPv2c and described in RFC 1901 [RFC1901] and RFC 1906 [RFC1906]. The third version of the message protocol is called SNMPv3 and described in RFC 1906 [RFC1906], RFC 2572 [RFC2572] and RFC 2574 [RFC2574]. - Protocol operations for accessing management information. The first set of protocol operations and associated PDU formats is described in STD 15, RFC 1157 [RFC1157]. A second set of protocol operations and associated PDU formats is described in RFC 1905 [RFC1905]. - A set of fundamental applications described in RFC 2573 [RFC2573] and the view-based access control mechanism described in RFC 2575 [RFC2575]. A more detailed introduction to the current SNMP Management Framework can be found in RFC 2570 [RFC2570]. Managed objects are accessed via a virtual information store, termed the Management Information Base or MIB. Objects in the MIB are defined using the mechanisms defined in the SMI. 4. An Introduction to the MPLS Working Group MIB Modules This section addresses the MIB documents produced by the MPLS working group, namely MPLS TC MIB, MPLS LSR MIB, MPLS TE MIB, MPLS LDP MIB, MPLS FTN MIB, and MPLS LINK BUNDLING MIB. The rest of this section briefly describes the following: Nadeau, Srinivasan and Farrel [Page 4] Internet Draft draft-ietf-mpls-mgmt-overview-03.txt February 2003 - the MPLS Object Identifier (OID) tree structure and the position of different MPLS related MIBs on this tree; - the purpose of each of the MIB modules within the MIB documents, what it can be used for, and how it relates to the other MIB modules. 4.1. Structure of the MPLS MIB OID Tree The MPLS MIB OID tree has the following structure. transmission -- RFC1213-MIB [RFC1213] | +- mplsMIB (166?) -- MPLS-TC-MIB | | | +- mplsTCMIB (1) -- MPLS-TC-MIB | | | +- mplsLsrMIB (2) -- MPLS-LSR-MIB | | | +- mplsTeMIB (3) -- MPLS-TE-MIB | | | +- mplsLdpMIB (4) -- MPLS-LDP-MIB | | | +- mplsLdpAtmMIB (5) -- MPLS-LDP-ATM-MIB | | | +- mplsLdpFrameRelayMIB (6) -- MPLS-LDP-FRAME-RELAY-MIB | | | +- mplsLdpGenericMIB (7) -- MPLS-LDP-GENERIC-MIB | | | +- mplsFTNMIB (8) -- MPLS-FTN-MIB ? +- linkBundlingMIB (TBD) -- LINK-BUNDLING-MIB Note: OID information is pending assignment by IANA. Conflicts and absent information shown above will be included in a later revision. 4.2. MPLS-TC-MIB MPLS-TC-MIB defines textual conventions [RFC2579] and object identities that may be common to MPLS related MIB modules. These conventions allow multiple MIB modules to use the same syntax and format for a concept that is shared between the MIB modules. For example, labels are a central part of MPLS and need to be presented in many of the MIB modules. The textual convention for representing an MPLS label is defined in MPLS-TC-MIB. All of the other MPLS MIBs import this MIB so that they can use one or more of the textual conventions it defines. Nadeau, Srinivasan and Farrel [Page 5] Internet Draft draft-ietf-mpls-mgmt-overview-03.txt February 2003 4.3. MPLS-LSR-MIB MPLS-LSR-MIB describes managed objects for modeling a MPLS Label Switch Router (LSR). This puts it at the heart of the management architecture for MPLS. This MIB module is used to model and manage the basic label switching behavior of an MPLS LSR. It represents the label forwarding information base (LFIB) of the LSR and provides a view of the LSPs that are being switched by the LSR in question. Since basic MPLS label switching is common to all MPLS applications, this MIB is referenced by many of the other MPLS MIB modules. In general, MPLS-LSR-MIB provides a model of incoming labels on MPLS-enabled interfaces being mapped to outgoing labels on MPLS-enabled interfaces via a conceptual object called an MPLS cross-connect. MPLS cross-connect entries and their properties are represented in MPLS-LSR-MIB and are typically referenced by other MIB modules in order to refer to the underlying MPLS LSP. For example, MPLS-TE-MIB models traffic engineered tunnels. These tunnels map to one more underlying MPLS LSPs. MPLS-TE- MIB refers to the underlying LSP by pointing to cross- connect entries in MPLS-LSR-MIB. 4.4. MPLS-LDP-MIB MPLS-LDP-MIB describes managed objects used to model and manage the MPLS Label Distribution Protocol (LDP) [RFC3036]. LDP is one of the MPLS protocols used to distribute labels and establish LSPs. This MIB module contains objects common to all LDP implementations. For an LDP implementation, this MIB module must always be implemented along with one or more of the other LDP MIB modules from the following sections. 4.5. MPLS-LDP-GENERIC-MIB This MIB module must be supported by LDP implementations if LDP uses a Per Platform Label Space. This MIB Module contains tables for configuring MPLS Generic Label Ranges Although the LDP Specification does not provide a way for configuring Label Ranges for Generic Labels, the MIB does provide a way to reserve a range of generic labels because this was thought to be useful by the working group. Nadeau, Srinivasan and Farrel [Page 6] Internet Draft draft-ietf-mpls-mgmt-overview-03.txt February 2003 4.6. MPLS-LDP-ATM-MIB This MIB module must be supported by LDP implementations if LDP uses ATM as the Layer 2 medium. Tables in this MIB module allow for configuring LDP to use ATM. 4.7. MPLS-LDP-FRAME-RELAY-MIB This MIB module must be supported by LDP implementations if LDP uses FRAME RELAY as the Layer 2 medium. Tables in this MIB module allow for configuration of LDP to use Frame Relay. 4.8. MPLS-TE-MIB MPLS-TE-MIB describes managed objects that are used to model and manage MPLS Traffic Engineered (TE) Tunnels. This MIB module is based around a table that represents TE tunnels that either originate from, traverse via or terminate on the LSR in question or. The MIB module provides configuration and statistics objects needed for TE tunnels. 4.9. MPLS-FTN-MIB MPLS-FTN-MIB describes managed objects that are used to model and manage the MPLS FEC-to-NHLFE (FTN) mappings that take place at an ingress LER. A Label Edge Router (LER) is an LSR placed at the edge of an MPLS domain and passes traffic into and out of the MPLS domain. An ingress LER is responsible for classifying data and assigning it to a suitable LSP. This classification is done using Forwarding Equivalency Classes (FECs) that define the common attributes of data (usually packets) that will be treated in the same way. Once data has been classified it can be handed off to an LSP through the Next Hop Label Forwarding Entry (NHLFE). In the case of an IP-to-MPLS mapping, the FEC objects describe IP 5-tuples representing IP source and destination ranges, protocol ranges etc. Matching IP packets are mapped to an NHLFE that can either be an MPLS LSP or an MPLS TE tunnel. Nadeau, Srinivasan and Farrel [Page 7] Internet Draft draft-ietf-mpls-mgmt-overview-03.txt February 2003 4.10. MPLS-LINK-BUNDLING-MIB MPLS-LINK-BUNDLING-MIB describes managed objects that are used to model and manage link bundling in an MPLS network. The link bundling feature is designed to aggregate one or more similar data channels between a pair of LSRs into a bundled link. The data channel is referred to as a TE link and is a sub-interface capable of carrying MPLS traffic engineered traffic. A link bundle is a sub-interface that bonds the traffic of a group of one or more TE links. 4.11. MIB Interdependencies This section provides an overview of the relationship between the MPLS MIB modules described above. More details of these relationships are given below once the MIB modules have been discussed in more detail. The arrows in the following diagram show a 'depends on' relationship. A "MIB module A depends on MIB module B" relationship means that MIB module A uses a structure or textual convention defined in MIB module B, or that MIB module A contains a pointer (index or RowPointer) to an object in MIB module B. +-------> MPLS-TC-MIB | ^ | | | MPLS-LSR-MIB <-----------------+ | | +<------- MPLS-LDP-MIB ----------------->+ | ^ | | | | | +<-- MPLS-LDP-GENERIC-MIB | | | | | +<-- MPLS-LDP-ATM-MIB | | | | | +<-- MPLS-LDP-FRAME-RELAY-MIB | | | +<------- MPLS-TE-MIB ------------------>+ | ^ | | | | +<------- MPLS-FTN-MIB ----------------->+ Thus: - All the MPLS MIB modules depend on MPLS-TC-MIB. - MPLS-LDP-MIB, MPLS-TE-MIB and MPLS-FTN-MIB contain references to objects in MPLS-LSR-MIB. Nadeau, Srinivasan and Farrel [Page 8] Internet Draft draft-ietf-mpls-mgmt-overview-03.txt February 2003 - MPLS-LDP-GENERIC-MIB, MPLS-LDP-ATM-MIB and MPLS-LDP- FRAME-RELAY-MIB contain references to objects in MPLS- LDP-MIB. - MPLS-FTN-MIB contains references to objects in MPLS-TE- MIB. 4.12. Dependencies on External MIBs With the exception of MPLS-TC-MIB, all the MPLS MIB modules have dependencies on the Interfaces MIB [RFC2863]. They reference MPLS-capable interfaces in the Interfaces Table (ifTable) in this MIB. The Interfaces Group of MIB II defines generic managed objects for managing interfaces. The MPLS MIBs contain media-specific extensions to the Interfaces Group for managing MPLS interfaces. The MPLS MIB modules assume the interpretation of the Interfaces Group to be in accordance with [RFC2863] which states that ifTable contains information on the managed resource's interfaces and that each sub-layer below the internetwork layer of a network interface is considered an interface. Thus, the MPLS interface is represented as an entry in ifTable. The inter-relation of entries in ifTable is defined by the Interfaces Stack Group defined in [RFC2863]. 5. Tables, Scalars and Notifications in MPLS-LSR-MIB 5.1. Tables MPLS-LSR-MIB contains the following tables. - The interface configuration table (mplsInterfaceConfTable) is used for enabling MPLS on MPLS-capable interfaces. - The in-segment (mplsInSegmentTable) and out-segment (mplsOutSegmentTable) tables are used to configure and monitor LSP segments carrying data into and out of the LSR, respectively. - The cross-connect table (mplsXCTable) is used to associate in and out segments in order to form a cross- connect (i.e. to represent an LSP transiting the LSR). Nadeau, Srinivasan and Farrel [Page 9] Internet Draft draft-ietf-mpls-mgmt-overview-03.txt February 2003 - The label stack table (mplsLabelStackTable) allows the specification of multi-label stacks to be imposed on a given LSP at this LSR - The Traffic Parameter table (mplsTrafficParamTable) is used to specify and record LSP related traffic parameters. - The MPLS in-segment (mplsInSegmentPerfTable) and out- segment (mplsOutSegmentPerfTable) performance tables contain objects to measure the performance of LSPs. - The MPLS interface performance table (mplsInterfacePerfTable) has objects to measure MPLS performance on a per-interface basis. 5.2. Scalars Where tables in the MIB module have arbitrary indexes, scalars are provided to supply the next available index. This applies to mplsOutSegmentTable, mplsXCTable, mplsLabelStackTable and mplsTrafficParamTable. mplsMaxLabelStackDepth defines the maximum size of a imposed label stack supported at this LSR. mplsXCTrapEnable is used to enable and disable notifications from MPLS-LSR-MIB. 5.3. Notifications MPLS-LSR-MIB can issue two notifications (if notifications are enabled). - mplsXCUp reports when a cross-connect becomes active. - mplsXCDown reports when a cross-connect becomes inactive. 5.4. Dependencies Between MIB Module Tables The tables in MPLS-LSR-MIB are related as shown on the diagram below. The arrows indicate a reference from one table to another. Nadeau, Srinivasan and Farrel [Page 10] Internet Draft draft-ietf-mpls-mgmt-overview-03.txt February 2003 mplsInterfacePerfTable ^ | mplsInterfaceConfTable ^ ^ | | +----+ +----+ | | | mplsTrafficParamTable | mplsLabelStackTable | ^ ^ | ^ | | | | | mplsInSegmentTable mplsOutSegmentTable | | | | | +----> mplsXCTable <----+ | V V mplsInSegmentPerfTable mplsOutSegmentPerfTable 6. Tables, Scalars and Notifications in the LDP MIB 6.1. MIB Modules The MIB for LDP contains four MIB modules. This structure makes it easier for an implementation to select only those parts of the MIB that are relevant to it. The MIB Modules are the MPLS-LDP-MIB, the MPLS-LDP-GENERIC-MIB, the MPLS- LDP-ATM-MIB and the MPLS-LDP-FRAME-RELAY-MIB. The MPLS-LDP-MIB defines objects which are specific to LDP without any Layer 2 objects. The MPLS-LDP-GENERIC-MIB defines Layer 2 Per Platform Label Space objects for use with the MPLS-LDP-MIB and for use on Ehternet. The MPLS- LDP-ATM-MIB defines Layer 2 Asynchronous Transfer Mode (ATM) objects for use with the MPLS-LDP-MIB. The MPLS-LDP- FRAME-RELAY-MIB defines Layer 2 FRAME-RELAY objects for use with the MPLS-LDP-MIB. The MPLS-LDP-MIB Module MUST be supported and at least one of the Layer 2 MIB Modules MUST be supported. 6.2. Tables The tables in the LDP MIB for configuring the LDP behavior of an LSR are as follows. - The LDP Entity Table (mplsLdpEntityTable) provides a way to configure the LSR for using LDP. There must be at least one LDP Entity for the LSR to support LDP. Each entry/row in this table represents a single LDP Entity. Nadeau, Srinivasan and Farrel [Page 11] Internet Draft draft-ietf-mpls-mgmt-overview-03.txt February 2003 - Several tables exist to help configure LDP's use of labels. These are spread through the MIB modules described in the previous section. They are: mplsLdpEntityGenLRTable, mplsLdpEntityAtmParmsTable and mplsLdpEntityAtmLRTable, mplsLdpEntityFrameRelayParmsTable and mplsLdpEntityFrLRTable. They are used to configure generic, ATM and Frame Relay labels as their names suggest. - The LDP Peer Table (mplsLdpPeerTable) is a read-only table, that contains information about LDP Peers known to LDP Entities. - The LDP Hello Adjacencies Table (mplsLdpHelloAdjacencyTable) is a table of all adjacencies between all LDP Entities and all LDP Peers. - Several tables exist to monitor and control LDP sessions. The LDP Session Table (mplsLdpSessionTable) represents sessions between an LDP Entity and a Peer. The mplsLdpAtmSesTable and mplsLdpFrameRelaySesTable contain session information specific to ATM. - The MPLS LDP Session Peer Address Table (mplsLdpSesPeerAddrTable) stores addresses learned after session initialization via Address Message advertisement. - The LDP FEC Table (mplsFecTable) represents FEC (Forwarding Equivalence Class) information that may be in use on one or more LSPs. The LDP LSP FEC Table (mplsLdpLspFecTable) shows the FECs associated with each LSP. - MPLS-LDP-MIB has a mapping table (mplsLdpLspTable) which maps the LDP MIB's representation of LDP sessions to the underlying LSR MIB's representation of the LSPs created by these sessions by pointing to mplsInSegmentTable, mplsOutSegmentTable and mplsXCTable, respectively. - Statistics may be gathered through the LDP Entity Statistics Table (mplsLdpEntityStatsTable) and the LDP Session Statistics Table (mplsLdpSesStatsTable) 6.3. Scalars Where tables in the MIB have arbitrary indexes, scalars are provided to supply the next available index. This applies to the mplsLdpEntityTable and the mplsFecTable. Two scalars exist to configure the LSR. The LSR ID is set in mplsLdpLsrId, and the loop detection capabilities are reported in mplsLdpLsrLoopDetectionCapable Nadeau, Srinivasan and Farrel [Page 12] Internet Draft draft-ietf-mpls-mgmt-overview-03.txt February 2003 6.4. Notifications MPLS-LDP-MIB defines four notifications that a device can issue. - mplsLdpInitSesThresholdExceeded is reported when the number of Session Initialization messages exceeds a configured threshold. - mplsLdpPVLMismatch is issued if the Path Vector Limit for a configured Entity and Peer do not match. - mplsLdpSessionUp and mplsLdpSessionDown report the transition of Session state. No scalar object is provided to enable and disable notifications from MPLS-LDP-MIB. Instead, the implementer is referred to [RFC2573]. 6.5. Dependencies Between MIB Module Tables The many tables in the four LDP MIB modules are related as shown on the diagram below. The arrows indicate a reference from one table to another. Note that in many cases the reference is through an augmentation of the referenced table. mplsLdpEntityGenLRTable ------------->+ mplsLdpEntityAtmParmsTable ---------->+ mplsLdpEntityAtmLRTable ------------->+ mplsLdpEntityFrameRelayParmsTable --->+ mplsLdpEntityFrLRTable -------------->+ mplsLdpEntityStatsTable ------------->+ | mplsLdpHelloAdjacencyTable | | | | mplsLdpEntityTable <--+ | ^ ^ V | | mplsLdpPeerTable <-+- mplsLdpSesPeerAddrTable ^ | | V mplsLdpSessionTable ^ ^ | | mplsLdpSesStatsTable ------+ +-- mplsLdpLspFecTable mplsLdpAtmSesTable --------+ | | | mplsLdpFrameRelaySesTable--+ | | V | | mplsFecTable | V +-- mplsLdpLspTable Nadeau, Srinivasan and Farrel [Page 13] Internet Draft draft-ietf-mpls-mgmt-overview-03.txt February 2003 7. Tables, Scalars and Notifications in MPLS-TE-MIB 7.1. Tables MPLS-TE-MIB contains the following tables. - The Tunnel table (mplsTunnelTable) is used to configure and report MPLS tunnels. Note that reporting of tunnels in this table at transit LSRs is optional. Entries in the mplsTunnelTable are indexed by four objects. The source and destination LSR Ids give context to the entry, and an index (mplsTunnelIndexIndex) identifies the tunnel itself. However, the fourth index (mplsTunnelInstance) may give rise to some confusion since its usage is not clearly explained. The description says: "Uniquely identifies an instance of a tunnel. It is useful to identify multiple instances of tunnels for the purposes of backup and parallel tunnels." In the case of backup tunnels, multiple instances of the same tunnel may be defined, but only one is active at any time. Different instances may have different properties (such as explicit routes), and one instance may be set up to protect against failure of another. Parallel tunnels may be used to provide load sharing or protection. The mplsTunnelInstancePriority object is used to indicate the precedence of tunnels with the same LSR Ids and mplsTunnelIndexIndex value. The mplsTunnelPrimaryInstance object gives a quick reference back to the preferred instance of the tunnel. The mplsTunnelIndexIndex value is typically signaled as the Tunnel ID, and the mplsTunnelInstance as the LSP Id in protocols where both fields exist. In protocols where there is only one identifying index (usually known as the LSP Id), only the mplsTunnelIndexIndex is signaled. - The Resource table (mplsTunnelResourceTable) is used to configure resources to be requested on this tunnel. The CRLDP resource table (mplsTunnelCRLDPResTable) is used to request additional resource details that are specific to tunnels signaled using CR-LDP. - The routes requested, computed and actually used for a tunnel are found in the Tunnel Hop Table (mplsTunnelHopTable) Tunnel Computed Hop Table (mplsTunnelCHopTable) and Tunnel Actual Hop Table (mplsTunnelARHopTable). - Statistics about the performance of tunnels may be gathered through the Tunnel Performance Table (mplsTunnelPerfTable). Nadeau, Srinivasan and Farrel [Page 14] Internet Draft draft-ietf-mpls-mgmt-overview-03.txt February 2003 7.2. Scalars Where tables in the MIB have arbitrary indexes, scalars are provided to supply the next available index. This applies to the mplsTunnelTable, the mplsTunnelResourceTable and the mplsTunnelHopTable. Two scalars exist to configure the support for MPLS tunnels on the LSR. mplsTunnelTEDistProto lists the signaling methods and protocols supported. mplsTunnelMaxHops defines the size of route that may be configured on the LSR. Two further scalars enhance the statistics on the LSR by counting the number of configured (mplsTunnelConfigured) and active (mplsTunnelActive) tunnels. The scalar mplsTunnelTrapEnable is used to enable and disable notifications from MPLS-TE-MIB. 7.3. Notifications MPLS-TE-MIB defines four notifications that a device can issue. - mplsTunnelUp and mplsTunnelDown report the transition of Tunnel state. - Rerouting and re-optimization of Tunnels paths are reported by mplsTunnelRerouted and mplsTunnelReoptimized. 7.4. Dependencies Between MIB Module Tables The tables in MPLS-TE-MIB are related as shown on the diagram below. The arrows indicate a reference from one table to another. mplsTunnelPerfTable | V mplsTunnelTable ^ ^ | | mplsTunnelResourceTable +---mplsTunnelHopTable ^ | | +---mplsTunnelCHopTable mplsTunnelCRLDPResTable | +---mplsTunnelARHopTable Nadeau, Srinivasan and Farrel [Page 15] Internet Draft draft-ietf-mpls-mgmt-overview-03.txt February 2003 8. Tables, Scalars and Notifications in MPLS-FTN-MIB 8.1. Tables MPLS-FTN-MIB contains the following tables. - The FEC to NHLFE Table (mplsFTNTable) defines the FEC to NHLFE rules to be applied to incoming packets, and the actions to be taken on matching packets. - The FEC to NHLFE Map Table (mplsFTNMapTable) provides the capability to activate FTN rules defined in the mplsFTNTable on specific interfaces in the system. - Performance statistics for FTN rules are found in the mplsFTNPerfTable. 8.2. Scalars A single scalar (mplsFTNIndexNext) exists. It is used to supply the next valid index into the mplsFTNTable. 8.3. Notifications There are no notifications in this MIB. 8.4. Dependencies Between MIB Tables The tables in MPLS-FTN-MIB are related as shown on the diagram below. The arrows indicate a reference from one table to another. mplsFTNTable ^ ^ | | mplsFTNMapTable mplsFTNPerfTable 9. Tables and Objects in MPLS-LINK-BUNDLING-MIB 9.1. Tables MPLS-LINK-BUNDLING-MIB contains the following tables. - The TE link table (teLinkTable) is used to specify TE links, including bundled links, and their generic traffic engineering parameters. - The TE link descriptor table (teLinkDescriptorTable) is used to list the TE link descriptors. Nadeau, Srinivasan and Farrel [Page 16] Internet Draft draft-ietf-mpls-mgmt-overview-03.txt February 2003 - The TE link OSPF traffic engineering table (teLinkOspfTeTable) is used for configuring OSPF traffic engineering parameters associated with TE links. - The shared risk link group (SRLG) table (teLinkSrlgTable) is used to specify the SRLGs associated with TE links. - The TE link bandwidth table (teLinkBandwidthTable) is used to report priority-based bandwidth values associated with TE links. - The data-bearing channel table (dataBearingChannelTable) is used to identify the data- bearing channels that are associated with the TE links and specify the data-bearing channel generic traffic engineering parameters. - The data-bearing channel link descriptor table (dataBearingChannelDescriptorTable) is used to list the data-bearing channel link descriptors. - The data-bearing channel bandwidth table (dataBearingChannelBandwidthTable) is used to report priority-based bandwidth values associated with data- bearing channels. 9.2. Scalars A single scalar (linkBundlingTrapEnable) exists. It is used to enable and disable notifications from the MIB from being issued by a device. 9.3. Notifications A single notification is defined. - linkBundleMismatch is generated when a mismatch of TE parameters between members of a bundled link is found. 9.4. Dependencies Between MIB Module Tables The tables in MPLS-LINK-BUNDLING-MIB are related as shown on the diagram below. The arrows indicate a reference from one table to another. Note that many of the associations between tables are through a common index that is the ifIndex of the related interface. Nadeau, Srinivasan and Farrel [Page 17] Internet Draft draft-ietf-mpls-mgmt-overview-03.txt February 2003 teLinkTable ^ | teLinkOspfLinkTable -----+ | teLinkDescriptorTable ---+ | teLinkSrlgTable ---------+ | teLinkBandwidthTable ----+ dataBearingChannelTable ^ | dataBearingChannelDescriptorTable ---+ | dataBearingChannelBandwidthTable ----+ 10. MIB Table Dependencies Between MPLS MIBs Section 4.8 gave an overview of how the MPLS MIB modules are related. Now that the tables in the MIB modules have been introduced, it is possible to give a more detailed diagram of these relationships. MPLS-TC-MIB is left off the diagram since so many of the MIB module tables use textual conventions from that MIB module. mplsLsrXCTable mplsLsrInSegmentTable ^ ^ | | +---- mplsLdpLspTable | | mplsTunnelTable ------+ V ^ | mplsLsrOutSegmentTable | | mplsFTNTable ---------+ 11. A Note on Interfaces The Interfaces Group of MIB II defines generic managed objects for managing interfaces. The MPLS MIBs make references to interfaces in order that it can be clearly determined where the procedures managed by the MIBs should be performed. Additionally, the MPLS MIBs (notably the MPLS-TE-MIB and the MPLS-LINK-BUNDLING-MIB) utilize interface stacking within the Interface Group. Nadeau, Srinivasan and Farrel [Page 18] Internet Draft draft-ietf-mpls-mgmt-overview-03.txt February 2003 11.1. MPLS Tunnels as Interfaces The MPLS-TE-MIB builds on the concept of managing MPLS Tunnels as logical interfaces. [RFC2863] states that the interfaces table (ifTable) contains information on the managed resource's interfaces, and that each sub-layer below the internetwork layer of a network interface is considered an interface. Thus, an MPLS Tunnel managed as an interface is represented as an entry in the ifTable. The interrelation of entries in the ifTable is defined by the Interfaces Stack Group defined in [RFC2863]. When using MPLS Tunnels as interfaces, the interface stack table might appear as follows: +------------------------------------------------+ | MPLS tunnel interface ifType = mplsTunnel(150) | +------------------------------------------------+ | MPLS interface ifType = mpls(166) | +------------------------------------------------+ | Underlying layer | +------------------------------------------------+ In the diagram above, "Underlying layer" refers to the ifIndex of any interface type for which MPLS internetworking has been defined. Examples include ATM, Frame Relay, and Ethernet. A detailed listing of the mapping between ifTable objects and their use for MPLS Tunnels is given in [TCMIB]. A few key objects are listed here to provide an overview of the concepts. Each MPLS tunnel is represented by an entry in the ifTable. Each tunnel is therefore assigned a unique ifIndex. The type of an interface represented by an entry in the ifTable is indicated by the ifType object. The value that is allocated to identify an MPLS tunnel is 150. The ifOperStatus object reflects the actual operational status of MPLS tunnel and may be mapped from the mplsTunnelOperStatus object. It may be considered convenient and good management to set the ifName object to reflect the name of the MPLS tunnel as contained in the mplsTunnelName object. 11.2. Application of the Interfaces Group to TE Links The MPLS-LINK-BUNDLING-MIB also uses interface stacking to manage TE Link interfaces as logical interfaces. The TE Link interface is represented as an entry in the ifTable. The inter-relation of entries in the ifTable is defined by Interfaces Stack Group defined in [RFC2863]. When using TE Link interfaces, the interface stack table might appear as follows: Nadeau, Srinivasan and Farrel [Page 19] Internet Draft draft-ietf-mpls-mgmt-overview-03.txt February 2003 +---------------------------------------------------------------+ | MPLS interface ifType = mpls(166) | +---------------------------------------------------------------+ | TE link-interface (bundle) ifType = teLink(200) | +------------------------------+-+------------------------------+ | TE link ifType = teLink(200) | | TE link ifType = teLink(200) | +-------------+--+-------------+ +-------------+--+-------------+ |opticalTrans | |opticalTrans | |opticalTrans | |opticalTrans | |ifType = 196 | |ifType = 196 | |ifType = 196 | |ifType = 196 | +-------------+ +-------------+ +-------------+ +-------------+ In the above diagram, "opticalTrans" is an example of an underlying physical interface: in this case an optical transport interface. TE link management and bundling can be seen in the levels of interface stacking. Two TE links are defined each managing two optical transport links. These two TE links are combined into a bundle which is managed as a single TE link interface. This TE Link interface supports MPLS and is presented as an MPLS interface. A detailed listing of the mapping between ifTable objects and their use for TE Links is given in [LBMIB]. A few key objects are listed here to provide an overview of the concepts. Each TE Link interface is represented by a separate entry in the ifTable with a unique ifIndex. The type of an interface represented by an entry in the ifTable is indicated by the ifType object. The value that is allocated to identify a TE Link 200. 11.3. References to Interface MIB Objects from Other MPLS MIBs The MPLS-TE-MIB contains two objects that reference the management of an MPLS tunnel as an interface. mplsTunnelIsIf is a TRuthValue that indicates whether the tunnel is present in the ifTable. If the tunnel is managed as an interface, the mplsTunnelIfIndex object contains the ifIndex that identifies the corresponding entry in the ifTable. The MPLS-LSR-MIB includes a table (mplsInterfaceConfTable) for configuring the support for MPLS on specific interfaces. A conceptual row in this table is created automatically by an LSR for every interface that is capable of and configured for support of MPLS. A conceptual row in this table will exist if and only if a corresponding entry in ifTable exists with ifType = mpls(166). The fate of the entries in the two tables are closely linked so that if the entry in the ifTable is operationally disabled, the entry in the mplsInterfaceConfTable is deleted. During the life of an entry in the mplsInterfaceConfTable a corresponding entry is managed in the mplsInterfacePerfTable to show performance counters for the MPLS-capable interface. Nadeau, Srinivasan and Farrel [Page 20] Internet Draft draft-ietf-mpls-mgmt-overview-03.txt February 2003 The ifIndex that identifies MPLS-capable interfaces also plays an important indexing role in the MPLS-LSR-MIB. In- segments (that is incoming LSP labels) are represented in the mplsInSegmentTable which is indexed by the mplsInSegmentIfIndex and mplsInSegmentLabel objects. mplsInSegmentIfIndex is set to the ifIndex of the incoming MPLS-capable interface. mplsInSegmentLabel identifies the incoming MPLS label. Note that the corresponding mplsOutSegmentTable contains an mplsOutSegmentIfIndex object to identify the outgoing MPLS-capable interface, but that this does not form part of the index of the table. The MPLS-LDP-MIB use ifIndex extensively to identify the interface over which MPLS is active. Within the MPLS-FTN-MIB, the mplsFTNMapTable maps entries in the mplsFTNTable to interfaces on which the mplsFTNTable entries should be used. Interfaces are identified using their ifIndex values. 12. Management Options It is not the intention of this document to provide instructions or advice to implementers of Management Stations, Management Agents or managed entities. It is, however, useful to make some observations about how the MIB modules described above might be used to manage MPLS systems. All MPLS LSPs may appear in the MPLS-LSR-MIB. At transit nodes they are seen as full cross-connects between incoming labels on incoming interfaces and outgoing labels on outgoing interfaces. At ingress or egress points the cross- connections are unbalanced having spoof upstream or downstream legs respectively. Split and merge points of LSPs may be represented as more complex cross-connects in the MPLS-LSR-MIB. Similarly, bidirectional LSPs can be represented by using the same cross-connect index for each of the forward and reverse cross-connections. The modules in the LDP MIB are intended solely for use with LDP and CR-LDP. LSPs that are signaled through other means may conveniently be stored in the mplsLdpLspTable for consistency with LSPs set up using LDP, but there is little further value to this since the table gives only pointers into the MPLS-LSR-MIB. If, however, the LSPs are established with associated FECs using some signaling method other than LDP (for example, BGP) it may be advantageous to use the mplsLdpLspTable, mplsFecTable and mplsLdpLspFecTable to correlate the LSPs. Nadeau, Srinivasan and Farrel [Page 21] Internet Draft draft-ietf-mpls-mgmt-overview-03.txt February 2003 Note that if CR-LDP is the signaling protocol there is no requirement to use the LSP-related tables in the LDP MIB since the LSP will be adequately represented in the MPLS-TE- MIB and the MPLS-LSR-MIB. MPLS tunnels may be represented in the MPLS-TE-MIB with their cross-connects indicated in the MPLS-LSR-MIB. Tunnels are often (although not always) set up with a series of constraints that may be represented in the MPLS- TE-MIB. Note that a distinguishing feature of a tunnel is that it has an ingress and an egress, where LSPs established through LDP may be end-to-end or may be hop-by- hop. All LSPs (tunnels and non-tunnels) may be established as a result of signaling protocols already defined or for future study. In addition, LSPs may be manually set up by issuing configuration commands to each of the LSRs on the LSP. These commands may utilize SNMP by performing write operations to the MIB tables and objects described here. Alternatively, configuration may be through some non- standard interface such as a Command Line or a Graphical User Interface. Such configured LSPs may also be represented in the MIB tables. Do not be mislead by considerations of the "permanence" of LSPs when deciding which tables of which MIB modules to use. An MPLS tunnel may have a very long life expectancy if set up by an amnesiac user, or a very short lifetime is automatically provisioned to satisfy on-demand traffic requirements. Similarly, an LSP established in response to a routing protocol (sometimes known as a hop-by-hop LSP) may be equally stable or unstable. 13. Related IETF MIB Modules This section describes the broad interactions between MIB modules produced by the pwe3, ppvpn, and ccamp working groups and the MPLS MIB modules. 13.1. pwe3 Working Group MIB Modules The pwe3 working group has produced a document [PWE3FW] that includes a description of the framework for PWE3 MIBs. Since the PWE3 architecture includes the use of MPLS as an emulated service and as a PSN service, the MPLS MIBs described above may be leveraged. The pwe3 framework document describes the interactions between the MPLS MIBs and the PWE3 MIBs. Nadeau, Srinivasan and Farrel [Page 22] Internet Draft draft-ietf-mpls-mgmt-overview-03.txt February 2003 13.2. ppvpn Working Group MIB Modules At present, the ppvpn working group has not included a discussion of how the MPLS MIBs interact with the MIBs being produced by that working group. The authors of this draft hope to make a forthcoming addition to the ppvpn framework document [PPVPNFW] detailing these interactions. At the moment, there is only a single MIB module [VPNMIB] produced which is discussed next. 13.2.1. PPVPN-MPLS-VPN-MIB PPVPN-MPLS-VPN-MIB describes managed objects that are used to model and manage RFC2547bis MPLS VPNs [RFC2547Bis]. This MIB module contains tables which model virtual routing forwarding entries (VRFs), as well as the interfaces associated with those VRFs. 13.2.1.1. Position in the OID Tree transmission -- RFC1213-MIB | +- vpnMIB (TBD) -- PPVPN-MPLS-VPN-MIB 13.2.1.2. Dependencies This MIB module currently has no direct dependencies to any of the MPLS MIB modules. This MIB module models MPLS VPN interfaces as entries in the Interfaces MIB's Interfaces Table (ifTable). This MIB module may be modified in the future to import textual conventions from MPLS-TC-MIB. 13.3. ccamp Working Group MIBs At present, there are no MIBs produced by the ccamp working group that interact directly with the MPLS MIBs. However, in the future, the existing MPLS MIBs will need to be extended and augmented to facilitate the technology being produced by this working group. Along with any MIBs produced by the ccamp working group, a separate ccamp- specific Management Framework document is expected to be issued describing the relationship between these MIBs and the existing MPLS (and other) MIBs. 14. Traffic Engineering Working Group TE MIB The tewg has produced a traffic engineering MIB [TEWGMIB] containing objects for monitoring traffic engineered MPLS based tunnels at their ingress points. In many senses the tewg TE MIB contains the same information as MPLS-TE-MIB. Both MIBs can be used to monitor MPLS tunnels. Nadeau, Srinivasan and Farrel [Page 23] Internet Draft draft-ietf-mpls-mgmt-overview-03.txt February 2003 The tewg TE MIB was initially styled towards simple textual representation of information about tunnels. This made it simple to implement as a read only MIB, displaying details of existing tunnels that were configured or established through other means. As write access has been added, the MIB continues to allow simple representations of tunnels. The price of this simplicity within the MIB, however, is an increased complexity in the Management Station or greater sophistication in the operator. It is necessary to apply parsing rules to text strings to in order to fully interpret or to configure tunnels. Many advanced features of MPLS tunnels are not included in this MIB. 14.1. Choosing Between TE MIBs Modules The tewg TE MIB is a flexible MIB designed to manage traffic engineering tunnels regardless of the implementation technology. This flexibility and a focus on simplicity leads to many compromises. Some MPLS configuration parameters are left out, while others are present with only limited options. MPLS-TE-MIB should be used for a fully configurable high function implementation. It provides objects for managing all features of MPLS Tunnels. The tewg TE MIB may be used for quick implementation or for non-complex situations. It may be particularly suitable for read-only inspection of tunnels established by some other means (such as a CLI). 15. Security Considerations This document describes the inter-relationships amongst the different MIBs relevant to MPLS management and as such does not have any security implications beyond those imposed by these MIBs themselves. 16. Acknowledgements Many small pieces of text in this draft have been borrowed from the documents that define the MIBs described here. The authors would like to express appreciation to all who worked on those MIBs. Thanks also to all those who attended the November 2002 MPLS MIB open meeting and gave constructive feedback, and in particular to Sharon Chisholm for her thoughts on Management Options. Nadeau, Srinivasan and Farrel [Page 24] Internet Draft draft-ietf-mpls-mgmt-overview-03.txt February 2003 17. Intellectual Property Consideration The IETF takes no position regarding the validity or scope of any intellectual property 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; neither does it represent that it has made any effort to identify any such rights. Information on the IETF's procedures with respect to rights in standards-track and standards-related documentation can be found in BCP-11. Copies of claims of rights made available for publication 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 implementors or users of this specification can be obtained from the IETF Secretariat. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights which may cover technology that may be required to practice this standard. Please address the information to the IETF Executive Director. 18. Normative References [TCMIB] Nadeau, T., Cucchiara, J., Srinivasan, C, Viswanathan, A. and H. Sjostrand, "Definition of Textual Conventions and OBJECT-IDENTITIES for Multi-Protocol Label Switching (MPLS) Management", Internet Draft , January 2002 (work in progress). [LSRMIB] Srinivasan, C., Viswanathan, A. and T. Nadeau, "MPLS Label Switch Router Management Information Base", Internet Draft , October 2002 (work in progress). [LDPMIB] J. Cucchiara, et al., "Definitions of Managed Objects for the Multiprotocol Label Switching, Label Distribution Protocol (LDP)", , October 2002 (work in progress). [TEMIB] Srinivasan, C., Viswanathan, A. and T. Nadeau, "MPLS Traffic Engineering Management Information Base Using SMIv2", Internet Draft , November 2002 (work in progress). Nadeau, Srinivasan and Farrel [Page 25] Internet Draft draft-ietf-mpls-mgmt-overview-03.txt February 2003 [FTNMIB] Nadeau, T., Srinivasan, C., and A. Viswanathan, "Multiprotocol Label Switching (MPLS) FEC-To-NHLFE (FTN) Management Information Base", Internet Draft , November 2002 (work in progress). [LBMIB] Dubuc, M., Dharanikota, S., Nadeau, T., J. Lang, "Link Bundling Management Information Base Using SMIv2", Internet Draft , November 2002 (work in progress). [VPNMIB] Nadeau, T., Fang, L., Van Der Linde, H., Brannon, S., Chiussi, F., Dube, J, and M. Tatham, "MPLS/BGP Virtual Private Network Management Information Base Using SMIv2", Internet Draft, , November 2002 (work in progress). [PWE3FW] Pate, P., Xiao, X., White., C., Kompella., K., Malis, A., Johnson, T., and T. Nadeau, "Framework for Pseudo Wire Emulation Edge-to- Edge (PWE3)", Internet Draft , June, 2002 (work in progress). [PPVPNFW] Callon, R., Suzuki, M., Gleeson, B., Malis, A., Muthukrishnan, K., Rosen, E., Sargor, C., and J. Yu, "A Framework for Provider Provisioned Virtual Private Networks", Internet Draft , January 2003 (work in progress). [RFC2863] McCloghrie, K. and F. Kastenholtz, "The Interfaces Group MIB ", RFC 2863, June 2000. 19. Informative References [RFC2547Bis] Rosen, E. et al, "MPLS/BGP VPNs", Internet Draft , October 2002. [TEWGMIB] Kompella, K., "A Traffic Engineering MIB", Internet Draft , September 2002 (work in progress). [RFC1155] Rose, M., and K. McCloghrie, "Structure and Identification of Management Information for TCP/IP-based Internets", RFC 1155, May 1990. [RFC1157] Case, J., Fedor, M., Schoffstall, M., and J. Davin, "Simple Network Management Protocol", RFC 1157, May 1990. Nadeau, Srinivasan and Farrel [Page 26] Internet Draft draft-ietf-mpls-mgmt-overview-03.txt February 2003 [RFC1212] Rose, M., and K. McCloghrie, "Concise MIB Definitions", RFC 1212, March 1991. [RFC1213] McCloghrie, K, and M. Rose, "Management Information Base for Network Management of TCP/IP Based Internets", RFC 1213, March 1991. [RFC1215] M. Rose, "A Convention for Defining Traps for use with the SNMP", RFC 1215, March 1991. [RFC1901] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Introduction to Community-based SNMPv2", RFC 1901, January 1996. [RFC1905] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Protocol Operations for Version 2 of the Simple Network Management Protocol (SNMPv2)", RFC 1905, January 1996. [RFC1906] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Transport Mappings for Version 2 of the Simple Network Management Protocol (SNMPv2)", RFC 1906, January 1996. [RFC2026] S. Bradner, "The Internet Standards Process -- Revision 3", RFC 2026, October 1996. [RFC2570] Case, J., Mundy, R., Partain, D., and B. Stewart, "Introduction to Version 3 of the Internet-standard Network Management Framework", RFC 2570, April 1999. [RFC2571] Harrington, D., Presuhn, R., and B. Wijnen, "An Architecture for Describing SNMP Management Frameworks", RFC 2571, April 1999. [RFC2572] Case, J., Harrington D., Presuhn R., and B. Wijnen, "Message Processing and Dispatching for the Simple Network Management Protocol (SNMP)", RFC 2572, April 1999. [RFC2573] Levi, D., Meyer, P., and B. Stewart, "SNMPv3 Applications", RFC 2573, April 1999. [RFC2574] Blumenthal, U., and B. Wijnen, "User-based Security Model (USM) for version 3 of the Simple Network Management Protocol (SNMPv3)", RFC 2574, 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. Nadeau, Srinivasan and Farrel [Page 27] Internet Draft draft-ietf-mpls-mgmt-overview-03.txt February 2003 [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. [RFC3031] Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol Label Switching Architecture", RFC 3031, January 2001. [RFC3036] Andersson, L., Doolan, P., Feldman, N., Fredette, A., and B. Thomas, "LDP Specification", RFC 3036, January 2001. 20. Authors' Addresses Thomas D. Nadeau Cisco Systems, Inc. 300 Apollo Drive Chelmsford, MA 01824 Phone: +1-978-244-3051 Email: tnadeau@cisco.com Cheenu Srinivasan Parama Networks, Inc. 1030 Broad Street Shrewsbury, NJ 07702 Phone: +1-732-544-9120 x731 Email: cheenu@paramanet.com Adrian Farrel Movaz Networks, Inc. 7926 Jones Branch Drive, Suite 615 McLean, VA 22102 Phone: +1-703-847-1867 Email: afarrel@movaz.com Nadeau, Srinivasan and Farrel [Page 28] Internet Draft draft-ietf-mpls-mgmt-overview-03.txt February 2003 21. Full Copyright Statement Copyright (C) The Internet Society (2003). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS 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. Nadeau, Srinivasan and Farrel [Page 29]