A fast switched backplane for a gigabit switched router

This paper motivated using switched backplanes for router designs. Although i don't have too much background in this area of specific router design, but it seems like the backplane they were talking about was basically the interconnect within the router that connects the input to output. It seems that previous to this paper, this interconnect was a bus. Buses in general have several disadvantages including its scalability and also contention, which is also mentioned in the paper. Thus, changing to a cross bar has it obvious advantages that now multiple packets and request can be forwarded to the outputs at the same time, thus increasing the bandwidth of the backplane. The paper then went on to explain the different design areas of a switched network.

Since i don't have much background on router designs, it's hard for me to comment on this paper. But it seems like since i started studying routers, what i learned was that the interconnect between input and output was a cross bar. Thus, i was quite shocked to hard that it used to be a single bus connecting everything. However, multicast does seem like it would be easier to do on a single bus, because i could imagine all of the outputs seeing the broadcast at the same time since they are all on the same bus. But as we move towards higher speed networks and domains, routers need to be able to support and keep up with the network.