IS-IS: Deployment in IP Networks

MPLS Capabilities

Let's look at each of these capabilities a little more closely, and then discuss how IS-IS has been modified to interact with MPLS.

Faster Packet Switching

At the time MPLS was envisioned, routers generally switched packets in software, using slow algorithms to determine the best next hop and rewrite the packet header. With the increasing speeds common in today's networks, however, more and more is being done to move most of the work involved in forwarding packets into hardware. In fact, the differences between routers, which traditionally forward packets in software, and switches, which traditionally forward packets in hardware, are fading.

Almost all routers are now layer three switches, since they do most of the work of actually ...