RTGWG S. Ning
Internet-Draft Tata Communications
Intended status: Informational D. McDysan
Expires: December 17, 2013 Verizon
E. Osborne
Cisco
L. Yong
Huawei USA
C. Villamizar
Outer Cape Cod Network
Consulting
June 15, 2013
Composite Link Framework in Multi Protocol Label Switching (MPLS)
draft-ietf-rtgwg-cl-framework-03
Abstract
This document specifies a framework for support of composite link in
MPLS networks. A composite link consists of a group of homogenous or
non-homogenous links that have the same forward adjacency and can be
considered as a single TE link or an IP link in routing. A composite
link relies on its component links to carry the traffic over the
composite link. Applicability is described for a single pair of
MPLS-capable nodes, a sequence of MPLS-capable nodes, or a set of
layer networks connecting MPLS-capable nodes.
Status of this Memo
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Copyright Notice
Copyright (c) 2013 IETF Trust and the persons identified as the
Ning, et al. Expires December 17, 2013 [Page 1]
Internet-Draft Composite Link Framework June 2013
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Background . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2. Architecture Summary . . . . . . . . . . . . . . . . . . . 4
1.3. Conventions used in this document . . . . . . . . . . . . 5
1.4. Terminology . . . . . . . . . . . . . . . . . . . . . . . 5
1.5. Document Issues . . . . . . . . . . . . . . . . . . . . . 5
2. Composite Link Key Characteristics . . . . . . . . . . . . . . 7
2.1. Flow Identification . . . . . . . . . . . . . . . . . . . 7
2.2. Composite Link in Control Plane . . . . . . . . . . . . . 10
2.3. Composite Link in Data Plane . . . . . . . . . . . . . . . 13
3. Architecture Tradeoffs . . . . . . . . . . . . . . . . . . . . 14
3.1. Scalability Motivations . . . . . . . . . . . . . . . . . 14
3.2. Reducing Routing Information and Exchange . . . . . . . . 15
3.3. Reducing Signaling Load . . . . . . . . . . . . . . . . . 16
3.3.1. Reducing Signaling Load using LDP . . . . . . . . . . 16
3.3.2. Reducing Signaling Load using Hierarchy . . . . . . . 17
3.3.3. Using Both LDP and RSVP-TE Hierarchy . . . . . . . . . 17
3.4. Reducing Forwarding State . . . . . . . . . . . . . . . . 17
3.5. Avoiding Route Oscillation . . . . . . . . . . . . . . . . 18
4. New Challenges . . . . . . . . . . . . . . . . . . . . . . . . 18
4.1. Control Plane Challenges . . . . . . . . . . . . . . . . . 19
4.1.1. Delay and Jitter Sensitive Routing . . . . . . . . . . 19
4.1.2. Local Control of Traffic Distribution . . . . . . . . 20
4.1.3. Path Symmetry Requirements . . . . . . . . . . . . . . 20
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