Internet Draft Summary

["Yufei Wang" <y.wang@virtualphotonics.com>]

Dear Sir:

Per IETF area requirement, I have attached a summary of a draft which I and
a co-author recently submitted targeting the Traffic Engineering Working
Group.
I would like to thank you in advance for your consideration.

Sincerely Yours,

Yufei Wang



NAME OF ID:

http://www.ietf.org/internet-drafts/draft-wang-te-hybrid-approach-00.txt

SUMMARY

   This draft proposes a novel, scalable and practical scheme for IP
   network traffic engineering. Currently the common approach to traffic
   engineering is the overlay method where explicit end to end MPLS LSPs
   between all possible edge nodes are established to form a full mesh
   virtual network on top of the physical topology. By carefully choosing
   the routes for these LSPs, one can completely control how traffic flows
   across the network and therefore achieve any given traffic engineering
   objective. However scalability is a serious concern with this approach
   because it requires N square number of LSPs where N is the number of
   nodes.

   In a recent research we discover a scalable traffic engineering method
   by optimizing the IGP link weights and show that theoretically the 
   native shortest path routing (OSPF or IS-IS) under appropriate link 
   weight setting matches the performance of the overlay approach exactly.
   But this theoretical result faces two major practical problems. One is
   that it only applies to static traffic engineering as link weights 
   cannot be changed too often due to IGP slow convergence. The other is
   that it may need to split traffic across multiple equal cost shortest
   paths if any, in unequal proportions and currently OSPF only supports
   equal splitting. We are proposing a new approach called the hybrid 
   approach which relies on both IGP link weight setting and MPLS LSPs. 
   The hybrid approach retains the scalability of the link weight method
   and at the same time eliminates the two practical problems of it. 
   The basic idea of this new approach is to rely on IP native routing
   (OSPF, IS-IS) for most part of the network and to use MPLS LSPs for
   load balancing at some locations only when necessary. The new approach
   achieves the exact performance of the overlay approach without 
   the associated complexity.

   

RELATED DOCUMENTS

   http://www.ietf.org/internet-drafts/draft-ietf-mpls-lsp-hierarchy-02.txt
   
 
WHERE DOES IT FIT IN THE PICTURE OF THE SUB-IP WORK

   TEWG

WHY IS IT TARGETED AT THIS WG

   This work proposes scalable traffic engineering approach which relies on
   both IGP link weight setting and MPLS LSPs. It is clear that the scope
   of this work is within the charter of the TE WG.

JUSTIFICATION
      
   TEWG is chartered to define, develop, specifie, and recommend
   principles, techniques, and mechanisms for traffic engineering in 
   the internet. This work is about a new set of traffic engineering 
   techniques and mechanisms which solve the key problem faced by carriers
   in their current practice of IP network traffic engineering. The
   importance of this work lies both in its innovation to enhance people's
   understanding on the fundamentals of traffic engineering methodology and
   in its impact on the ways carriers traffic-engineer their IP networks.