Policing on inter-as mpls

[prakashj]

Hi,

We are planning to have inter-as mpls vpn. We would like to configure policing for the customers on the inter-as link. As the inter-as link is a global interface on ASBRs how do we restrict the bandwidth for each vrf which passes over the link?

Thanks,

Prakash

[mheusinger]

Hi,

The beauty of MPLS to some extend is based on the label stack. A LSR does ONLY understand the top label. The VPN label in a MPLS VPN environment is only understood by the egress PE, which assigned it.

What you are asking is: How can I know the meaning of the second MPLS label in an intermediate LSR to differentiate between customers?

The answer imho is: you can?t.

What is possible to my knowledge is to use option 10a - VRF back-to-back and differentiating customers by subinterfaces.

Hm. Another option could be to setup a different LSP (BGP next hop) for each VRF and to combine it with static label mappings in the ASBRs. Still I am not sure a policer could match on certain label values. Besides, this would mean a LOT of administrative burden.

Hm. Another option: use experimental bits to differentiate traffic from different customers. Drawback: scales only up to 7 customers.

Regards, Martin

[prakashj]

Thanks Martin for your reply...

Hmm..so it is not possible to reserve bandwidth on a shared link. So the best option is to go for private interface for each VRF on ASBR as explained in RFC 4364.

I hope these restrictions will be addressed soon for a shared link. Maybe like present IXPs we can have MPLS Exchange points or inter-as mpls between the providers to save the cost of international TDM links... ;) ;)

Regards,

Prakash