CCAMP draft-dharanikota-interarea-mpls-te-ext-01.txt

[Senthil Venkatachalam <senthil.venkatachalam@usa.alcatel.com>]

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NAME OF I-D:

http://search.ietf.org/internet-drafts/draft-dharanikota-interarea-mpls-te-ext-01.txt

SUMMARY:

This draft proposes the extensions required to the routing protocols, 
signaling protocols, and the MIB to support inter-area LSPs. A companion 
document draft-venkatachalam-interarea-mpls-te-01.txt provides the 
architecture for such a method. This document also provides the signaling 
extensions to support the crankback feature as defined in the architecture 
document.
   
RELATED DOCUMENTS

http://www.ietf.org/internet-drafts/draft-venkatachalam-interarea-mpls-te-01.txt
http://www.ietf.org/internet-drafts/draft-venkatachalam-ospf-traffic-01.txt
http://www.ietf.org/internet-drafts/draft-ash-ccamp-multi-area-te-reqmts-00.txt

WHERE DOES IT FIT IN THE PICTURE OF THE SUB-IP WORK

CCAMP WG - Control C

WHY IS IT TARGETED AT THIS WG.

The setup of Label Switched Paths (LSPs) is a basic component of any MPLS
signalling mechanism. There are no standards that facilitate the setup of 
LSPs across IGP areas. This draft and its companion architecture draft
addresses this vaccum and presents a method to setup LSPs across IGP area 
boundaries within a domain. Included in this method are extensions to the 
existing signalling protocols (control function), extensions to the 
routing protocols (measurement function) and an overal architecture that 
describes the inter-area LSP method (use of control/measurement extensions).

In addition to other WG tasks, the following WG tasks specifically allows 
this work in the WG:

- Define the relationship between layer 3 routing protocols and the 
  common signalling protocol for establishing and maintaining paths.  

- Define how the properties of network resources gathered by the measurement 
  protocol can be distributed in existing routing protocols, such as OSPF 
  and IS-IS. 

- Develop and define a set of protocol-independent metrics and parameters 
  for describing links and paths that can be carried in protocols. 

JUSTIFICATION

Most work in the CCAMP and indeed many sub-ip groups focuses only 
on the intra-area LSP setup issues. In this work we propose an 
architecture to extend the traffic engineering capability across IGP areas 
and recommend relevant modifications to the routing protocols, signaling 
protocols and MIBs. 

The mechanism proposed in this draft extends the capabilities of the 
control plane of the sub-IP technology of MPLS. It recommends extensions 
to the routing protocols to help in the measurement of TE parameters for
the same purpose. In addition, the popular CSPF paradigm used in current
intra-area control and measurement protocols is extended to allow inter-area
CSPF computation and LSP setup. All of these concepts are integral to
the CCAMP features of sub-IP areas such as MPLS, IPO and other emerging 
technology areas which use both L3 routing and control (signaling) functions
to establish switched paths across IGP areas, be they LSPs, lightpaths or 
GMPLS paths.