Abstract:

An important factor behind the scalability of MPLS based L3-VPNs is the need for only one BGP protocol instance in the PE element. The best scalability is achieved, if eBGP is used as the protocol between CE and PE. Using OSPF as the CE-PE protocol or supporting a very large number of CEs present a challenge for the PE routing processor. An architecture for improving the scalability under these circumstances is presented. The solution is based on introducing an intermediate layer of multiplexing for routing information. This is done by adding an aggregation router between the CE and PE. The aggregation router supports VRFs, peers with the CE and multiplexes the CE routing information into an MP-eBGP session towards the PE. This removes the need for the PE to run OSPF instances and reduces the number of BGP peering sessions that the PE needs to maintain.

Antti Kankkunen is one of Tellabs veterans; he first joined the company in 1991. Currently, he is Chief Technical Officer of Managed Access Systems division. Antti Kankkunen has a degree of M.Sc. in Electrical Engineering from Helsinki University of Technology.