How MPLS VCs are related to LSPs?

[william.caban]

- How an MPLS VC of a pseudowire or xconnect is related to an LSP? Example, if I have two MPLS devices 10.1.1.1 and 10.2.2.2 as LDP peers. How: "xconnect 10.1.1.1 100 encapsulation mpls" will be related to the LSP between 10.1.1.1 and 10.2.2.2? Is the MPLS VC unique on per LSP basis, per chassis basis or per MPLS cloud basis?

Thanks in advance,

-W

[swaroop.potdar]

William, for a pseudowire, there are 2 labels, the tunnel label(IGP label) and the VC label.

Tunnel label is the same for all VC between those 2 PE, but the VC label is unique per device.

Directed LDP session is built using the existing LSP (using the IGP label for the remote PE) between the 2 PE's. There exists 1 directed LDP session between 2 PE's.

Over the directed LDP VC labels are exchanged which are the bound to the respective VC interface. This is unique per device.

HTH-Cheers,

Swaroop

[william.caban]

- So, will this means that any pseudowire or xconnect cause the establishment of a directed LDP session between the participant PEs?

- If I have two xconnects in A. Lets say, A->B and A->C and in both the xconnects use the VC 100. Will the VC 100 between A-B and VC 100 between A-C cause any conflict?