Inside Cisco IOS Software Architecture

Chapter 4. Early Cbus Routers

This chapter covers the following key topics:

• AGS+ Hardware Architecture

• Packet Switching with the Cbus

• The Cisco 7000 Series Router

Chapter 2, “Packet Switching Architecture,” examined how changes in the IOS software implementation have been used to improve packet switching performance. Cisco also uses special hardware designs to improve switching performance. The first notable example of this was the introduction of the Cbus with the AGS+ router and its successor, the Cisco 7000 series router, in the early 1990s. Although these products are no longer sold or supported in current IOS versions, a large part of their design was adapted for the Cisco 7500 series routers that are widely deployed today. This chapter ...