Evolution of the Cisco Switching Algorithms
The Cisco core product line has evolved through the generations, from the AGS of 1986 to the GSR of 1997. The next sections examine this evolution in more detail.
Process Switching
The original Cisco AGS was a central CPU packet switch that was similar to host-based routers, except that the range of protocols and interfaces supported was greater, and the operating system was optimized for packet-forwarding functions. Interface cards were connected to the CPU motherboard through the Motorola 16 Mbps Multibus, and interface cards maintained the simple packet buffers necessary when there was contention on the internal bus and external media (see Figure 5-2).
All packets were passed over the multibus ...
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