CCAMP draft-srisuresh-ospf-te-00.txt

[Pyda Srisuresh <srisuresh@yahoo.com>]

NAME OF I-D:
   Title: New TE LSAs to extend OSPF for Traffic Engineering
   URL::  http://www.ietf.org/internet-drafts/draft-srisuresh-ospf-te-00.txt

SUMMARY:
   OSPF is a well established link state routing protocol used for 
   topology discovery and computing forwarding table based on
   shortest-Path criteria. Traffic Engineering extensions (OSPF-TE)
   will use criteria different from shortest-path so as to route
   traffic around congestion paths and meet varying Service Level
   agreements. OSPF-TE may also be used by non-IP networks such as
   photonic and TDM (SONET/SDH) circuit switch networks for 
   light-path or TDM circuit setup between two end-points. The 
   approach outlined in this document differs from that of 
   [OPQLSA-TE]. The document does not suggest the use of Opaque LSAs
   to add TE extensions to OSPF. Rather, new TE LSAs, modeled after
   existing LSAs and flooding scope are proposed to overcome the
   scaling limitations of the approach outlined in [OPQLSA-TE]. The
   document draws a distinction between TE and non-TE topologies and
   restricts flooding of TE LSAs into non-TE topology.  The document
   covers OSPF extensions for packet and non-packet networks alike,
   providing a unified extension mechanism for all networks. As such,
   this approach improves interoperability between peer network
   elements. Lastly, the document specifies a transition path for
   vendors currently using opaque LSAs to transition to using new 
   TE LSAs outlined here.

RELATED DOCUMENTS:

 Competing documents:
   [OPQLSA-TE] Katz, D., D. Yeung and K. Kompella, "Traffic
               Engineering Extensions to OSPF", work in progress,
               <draft-katz-yeung-ospf-traffic-05.txt>
   [MAREA-TE]  Kompella, K., and Y. Rekhter, "Multi-area MPLS 
               Traffic Engineering", Work in progress.
               <draft-kompella-mpls-multiarea-te-01.txt>

  Operlapping TLV definitions (Complementary to this draft):
    [1]        Katz, D., D. Yeung and K. Kompella, "Traffic
               Engineering Extensions to OSPF", work in progress,
               <draft-katz-yeung-ospf-traffic-05.txt>
   
    [2]        Kompella et al., "OSPF extensions in support of
               Generalized MPLS", Work in progress, 
               <draft-kompella-ospf-gmpls-extensions-01.txt>



WHERE DOES IT FIT IN THE PICTURE OF THE SUB_IP WORK:

   Control portion of the CCAMP box.

WHY IS IS TARGETED AT THIS WG:
   By defining the TE extensions required of the OSPF routing protocol,
   this document addresses the following CCAMP WG task:

     - Using input from the TE working group, ensure that the signalling 
       and measurement protocols provide both the information and the 
       control functions adequate to support the traffic provisioning
       and engineering operations of service providers. 

JUSTIFICATION:
   (1) Collecting the traffic engineering topology and characteristics
       associated with TE is fundamental to provisioning traffic paths,
       enforcing SLAs and carrying out the necessary engineering 
       operations for the service providers. This is also the information
       used by the signaling protocols to communicate with the TE nodes.
       The approach outlined in this document differs from that of 
       [OPQLSA-TE] and [MAREA-TE].

   (2) The proposed mechanism is modeled after the proven OSPF LSA
       formats, area heirarchy and efficient flooding scope. The mechanism
       outlined overcomes the scaling limitations of the approach 
       outlined in [OPQLSA-TE]. A section in the document is devoted to
       drawing contrast withe the Opaque-LSA based TE approach.

   (3) The document draws a distinction between TE and non-TE 
       topologies and restricts flooding of TE LSAs into non-TE topology.
       As such this makes it intuitive and for service provider SLA 
       enforcement on a TE network.

   (4) The document provides a single unified OSPF TE extensions mechanism
       for packet and non-packet networks alike. As such, this approach
       improves interoperability between peer network elements. 

   (5) Lastly, the document specifies a transition path for vendors 
       currently using opaque LSAs to transition to using new 
       TE LSAs outlined here.

Thanks.

regards,
suresh & Paul


__________________________________________________
Do You Yahoo!?
Get personalized email addresses from Yahoo! Mail
http://personal.mail.yahoo.com/