Current Meeting Report

2.6.5 Multiprotocol Label Switching (mpls)

NOTE: This charter is a snapshot of the 53rd IETF Meeting in Minneapolis, MN USA. It may now be out-of-date. Last Modified: 11-Feb-02
George Swallow <>
Loa Andersson <>
Sub-IP Area Director(s):
Scott Bradner <>
Bert Wijnen <>
Sub-IP Area Advisor:
Scott Bradner <>
Technical Advisor(s):
Rob Coltun <>
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Description of Working Group:
The MPLS working group has been responsible for standardizing a base technology for using label switching and for the implementation of label-switched paths over various link-level technologies, such as Packet-over-Sonet, Frame Relay, ATM, and LAN technologies (e.g. all forms of Ethernet, Token Ring, etc.). This includes procedures and protocols for the distribution of labels between routers, encapsulations and multicast considerations.

The initial goals of the working group have been largely completed. In particular, it has produced a number of RFCs (see list below) that define the base Label Distribution Protocol (LDP), the basic MPLS architecture and encapsulations, and definitions for how MPLS runs over ATM and Frame Relay links.

The current goals of the working group are:

1. Complete outstanding items from the original MPLS effort:


(6/12) Applicability Statement for Extensions to RSVP for LSP-Tunnels (8/08) Applicability Statement for CR-LDP (6/12) LDP State Machine


(10/19/99) MPLS Loop Prevention Mechanism

Standards Track:

(8/08) Constraint-Based LSP Setup using LDP (2/07) Carrying Label Information in BGP-4 (8/29) Extensions to RSVP for LSP Tunnels (8/29) MPLS Support of Differentiated Services (6/27) LSP Modification Using CR-LDP (9/01) Definitions of Managed Objects for LDP (8/29) MPLS Label Switch Router Management Information Base

2. Advance the Proposed Standards developed by the MPLS WG to Draft Standard. This includes the LDP, CR-LDP, and RSVP-TE signaling specifications as well as the encapsulations.

3. Specify appropriate extensions to LDP and RSVP for authentication of LSP originators.

4. Complete work on the MPLS-TE MIB.

5. Specify improved fault tolerance mechanisms for LDP

6. Specify MPLS-specific recovery mechanisms to allow one label-switched path to be used as backup for a set of other label-switched paths, including cases which permit local repair. What constitutes the necessary set of MPLS-specific recovery mechanism should be ascertained through cooperation with the CCAMP and TE working groups.

7. Document additional MPLS encapsulations to allow the operation of label-switched paths over additional lower-layer technologies, such as time-division (e.g. SONET ADMs), wavelength (optical lambdas) and spatial switching (e.g. incoming fiber to outgoing fiber).

8. Complete work in progress for specifying the framework for IP multicast over label switched paths.

Goals and Milestones:
Done   Submit documents from original MPLS effort to IESG
Jan 01   Shepherd completed MPLS specifications through IESG review and RFC editor processing
Feb 01   MPLS-TE MIB ready for advancement to Proposed Standard
Mar 01   Framework for IP multicast over label-switched paths ready for advancement.
Jun 01   LDP fault tolerance specification ready for advancement to Proposed Standard.
Aug 01   Specification for MPLS-specific recovery ready for advancement.
Nov 01   Base MPLS Proposed Standard RFCs ready for advancement to Draft Standard.
Dec 01   LDP end-to-end LSP authentication ready for advancement to Proposed Standard.
Request For Comments:
RFC2702 Requirements for Traffic Engineering Over MPLS
RFC3031PSMultiprotocol Label Switching Architecture
RFC3032PSMPLS Label Stack Encoding
RFC3034PSUse of Label Switching on Frame Relay Networks Specification
RFC3035PSMPLS using LDP and ATM VC Switching
RFC3036PSLDP Specification
RFC3037PSLDP Applicability
RFC3038PSVCID Notification over ATM link for LDP
RFC3033PSThe Assignment of the Information Field and Protocol Identifier in the Q.2941 Generic Identifier and Q.2957 User-to-user Signaling for the Internet Protocol
RFC3063E MPLS Loop Prevention Mechanism
RFC3107PSCarrying Label Information in BGP-4
RFC3209PSRSVP-TE: Extensions to RSVP for LSP Tunnels
RFC3210 Applicability Statement for Extensions to RSVP for LSP-Tunnels
RFC3212PSConstraint-Based LSP Setup using LDP
RFC3213 Applicability Statement for CR-LDP
RFC3214PSLSP Modification Using CR-LDP
RFC3215 LDP State Machine

Current Meeting Report

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