BGP advancement

[Arjun Dabol]

Hello Experts, 

I read about some new advancements that Service providers are doing but I am unable to identify a clear difference (if there is any) among them : can someone help ?       

BGP 3107    

Inter AS option B   

BGP PIC-edge 

[Vasilii Mikhailovskii]

Hello, what are "advancements" you are comparing?

BGP PIC is one improvement, while Inter AS option B is really different story.

[Arjun Dabol]

these are some doubts :

1. Does inter AS Option B  use BGP 3107 ?
2. Are there Option A and C as well? what are they ?
3. what is concept behind  CSC ?
4. Does Unified MPLS also use BGP 3107 ?
5. When we say Lablel in VRF  : is it CSC or Option-B or BOTH ?

[Vinit Jain · Accepted solution]

Yes, there are Option A and C as well. Option A is back to back VRF method and the most easiest method. Option C is implemented with Multihop eBGP VPN session between Route Reflectors, but it doesn't have to be only RR, it could also be PEs. PEs from one carrier can have sessions to other PEs in the other carrier using a full mesh.

CSC is a Backbone ISP providing MPLS VPN + Labelling (Labelling over VRF) Services to smaller ISP's. Say for example, provider in location A and B gets MPLS VPN Services from backbone provider A where A and B provide MPLS VPN Services to their customers. the difference is A also provides labelling capability over VRF so there is an End to End LSP.

Now when the communication is happening between two different AS's its Inter-AS. Thus CSC can be formed like

Cust_A---(ISP-AS2) ------(BB-ISP-AS1)------(ISP-AS2)------Cust_A

or 

Cust_A---(ISP-AS2) ------(BB-ISP-AS1)------(ISP-AS3)------Cust_A

(BB stands for Backbone)

RFC 3107 is just about carrying label information in VPNv4 update. So most likely in CSC scenario.

Hope this clarifies

Vinit

[Vinit Jain]

RFC 3107 is not a new advancement. it was developed back in 2001. BGP PIC and BGP Add-Path features are some new developments along with BGP EVPN.

BGP PIC is nothing but BGP FRR which allows the installation of backup path. Same with the case with BGP Add-Path which is a more particular case for BGP multi-path across RR's. Refer to the below CCO documents for more information.

http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_bgp/configuration/xe-3s/irg-xe-3s-book/irg-additional-paths.html

http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_bgp/configuration/xe-3s/irg-xe-3s-book/irg-bgp-mp-pic.html

is there any particular thing that you have question on Inter-As option B?

Vinit

[Arjun Dabol]

Thanks . Yes I am unable to make difference between :

How inter AS Option B works  ? does it use BGP 3107 ?

Are there Option A and C as well?

what is concept behind  CSC ?

Does Unified MPLS also use BGP 3107 ?

Thanks in adv