Configuring Inter-AS VPWS

Usage Scenario

If multiple ASs exist on an MPLS backbone network, the VPWS network carried over the MPLS backbone network must be an inter-AS VPWS network.

Currently, the following inter-AS VPWS solutions are available:

• Inter-AS VPWS Option A: This solution can be easily deployed and is recommended for scenarios where few inter-AS VPWS PWs are required.
• Inter-AS VPWS Option C: ASBRs do not need to create or maintain PWs and, as a result, are not a significant factor in network expansion. This solution is recommended for scenarios where large numbers of inter-AS VPWS PWs are required.

Pre-configuration tasks

Before configuring inter-AS VPWS, complete the following tasks:

• Configure an IGP for each AS on the MPLS backbone network to ensure IP connectivity within the same AS.

• Configure basic MPLS functions for each AS on the MPLS backbone network.

• Configure MPLS LDP and establish LDP LSPs for each AS.

• Establish an IBGP peer relationship between the PE and ASBR in the same AS and an EBGP peer relationship between ASBRs in different ASs. This task is specific to inter-AS LDP VPWS Option C.