Tag switching architecture overview
Yakov Rekhter, Bruce S. Davie, Eric Rosen, George Swallow, Dino Farinacci, Dave Katz · Proceedings of the IEEE · 1997
Tag switching is a way to combine the label-swapping forwarding paradigm with network-layer routing with particular application to the Internet. This has several advantages. Tags can have a wide spectrum of forwarding granularities, so at one end of the spectrum a tag could be associated with a group of destinations, while at the other end, a tag could be associated with a single application flow. At the same time, forwarding based on tag switching, due to its simplicity, is well suited to high-performance forwarding. These factors facilitate the development of a routing system that is both functionally rich and scalable. Last, tag switching simplifies the integration of routers and asynchronous transfer mode switches by employing common addressing, routing, and management procedures.