MPLS label swapping done in hardware ?

[m-menozzi]

Some competitor claims that their implementations of MPLS are done trough software and hardware implementation. Does it mean that MPLS is done in hardware ?

Is there a doc that clarify how is performed label swapping by Cisco routers ?

And in software case how is the impact especially on medium-end platform like 36xx ?

Marco

[s.jankowski]

Cisco uses CEF switching along with TDP/LDP to build LFIB tables for MPLS, and then the LFIB table is used for label swapping. I think the hardware or software implementation could depend on the platform. For high end routers like 7500, distributed CEF can be used where the CEF tables are downloaded to te VIP and the VIP themselves could do the label swapping mechanism. This could be considered as hardware based label swapping. The low/medium end routers might do this through software. Though there will be a performance difference by doing it in software compared to hardware, i think it will not have too much impact, as the routers can easily swap fixed length labels.

[j.vanrooyen]

Basically the ASIC on the router or the VIP (Higher End Boxes) does the switching so yes , the switching is done in hardware .

There are a number of Cisco PDF's dealing with MPLS , best bet is to search CCO for the one that best suits your requirement.

As for 36xx running MPLS is no problem , we have a number of 3640's acting as PE nodes in a MPLS VRF environment but it all depends on number of interfaces etc.