[c-nsp] MPLS Multi-AS options...

[Kenny Sallee]

So I'm reading this document from Cisco:


http://www.cisco.com/en/US/docs/ios/mpls/configuration/guide/mp_vpn_ias_optab.html

and

http://www.cisco.com/en/US/docs/ios/mpls/configuration/guide/mp_vpn_connect_asbr.html
as
well as RFC 4364 section 10 "Multi-AS Backbones".


I'm wondering if anyone is actually doing any flavor of Multi-AS backbone
this in the real world?  Option A doesn't seem scalable at all.  Option B
seems scalable, but the level of trust and lack of QoS may be a concern.
Option AB - I'm trying to fully understand w/o a ton of lab time.  As I read
the first Cisco link above, with Option AB - you must configure a
sub-interface PER VPN/Client in it's own VRF on each SP's ASBR.  So if you
have 100 different customers, on that interconnect between SP1 and SP2 you
must configure 100 sub-interfaces, VRF's with unique (agree'd upon)RD's.
Then you configure a single MP-BGP session to carry the VPNv4 addresses for
all VRF's.  So really you are only saving X number of BGP sessions with
Option AB compared to say just Option A correct?

Anyone out there with practical experience doing this in a production
environment?

Thanks,

Kenny





  Is there any other technology for 'exteding VRF' to an Application Service
provider type network?