Pseudowire Label Switch Path Load Sharing

Pseudowire (PW) Label Switch Path (LSP) Load Sharing provides the ability for L2VPN PWs to use up to 16 or 64 Transport LSPs, depending on the platform, for carrying tunneled data across the MPLS network. Previously, Ethernet PWs could only use one tunnel LSP. This feature is related to traffic distribution over Link AggregationGroups (LAGs).

The current HW hashing algorithm on MPLS Transit Nodes uses MPLS labels to derive a hash value. In previous implementations where an L2VPN PW used only one Transport LSP, there were only two MPLS labels to hash on (the outer transport label, and inner VC label) for a given PW. In an eight-port LAG that L2VPN tunneled traffic would only be distributed to one or two links in the LAG. When a PW uses multiple Tunnel LSPs, there are more labels for the HW to use for hashing, and this allows improved distribution over LAG in MPLS Transit Nodes

Limitations

This feature has the following limitations:

Platforms Supported

This feature is supported on the following platforms:

  • ExtremeSwitching X460-G2 (16 LSPs)
  • ExtremeSwitching X670-G2 (16 LSPs)
  • ExtremeSwitching X770 (16 LSPs per PW)
  • ExtremeSwitching X870 (16 LSPs per PW)
  • ExtremeSwitching X590 (16 LSPs per PW)
  • ExtremeSwitching X690 (16 LSPs per PW)
  • ExtremeSwitching X695 (16 LSPs per PW)
  • ExtremeSwitching X465 (16 LSPs per PW)
  • ExtremeSwitching 5520 (8 LSPs per PW)