The All-New Switch Book: The Complete Guide to LAN Switching Technology, Second Edition

6.6. Interconnecting the Source-Routed and Transparently Bridged Universes

If the network environment comprises a pure, source-routed catenet, and all of the end stations and bridges follow the principles and algorithms dictated by source routing, the system should behave as expected. In particular, if there is an operational physical path present between any pair of end stations, those stations should be able to communicate using source routing. Similarly, if the catenet comprises a set of stations and bridges operating according to the rules of transparent bridging, we should also expect to be able to communicate among all stations in a manner consistent with that bridging method.

SOURCE ROUTING IS PROPERLY NAMED Consider some of the behavioral characteristics of a source-routed network: End stations are aware of the presence of source routing bridges. End stations can exchange frames across multiple links only by explicitly sending them through named bridges. Transmitted frames are modified to include routing instructions. End station software is required to effect frame delivery across multiple links beyond that required to deliver frames across a single link. The algorithms support operation across an arbitrary underlying topology, including simultaneous use of links that form a physical loop. These characteristics are much more descriptive of devices operating at the Network ...