An essential guide to understanding the Cisco IOS architecture

In-depth coverage of Cisco's IOS Software architecture provides crucial information to:

• Prevent network problems and optimize performance through more efficient design and configuration
• Isolate and resolve network problems more quickly and easily
• Apply the appropriate packet switching method, such as process switching, fast switching, optimum switching, or Cisco Express Forwarding (CEF)
• Understand the hardware architecture, packet buffering, and packet switching processes for shared memory routers (Cisco 1600, 2500, 3600, 4000, 4500, and 4700 series)
• Understand the hardware architecture, packet buffering, and packet switching processes for the Cisco 7200 series routers
• Understand the hardware architecture, packet buffering, and packet switching processes for the Cisco 7500 series routers
• Understand the hardware architecture, packet buffering, and packet switching processes for the Cisco GSR 12000 series routers
• Further your knowledge of how IOS Software implements Quality of Service (QoS)

Inside Cisco IOS Software Architecture offers crucial and hard-to-find information on Cisco's Internetwork Operating System (IOS) Software. IOS Software provides the means by which networking professionals configure and manage Cisco networking devices. Beyond understanding the Cisco IOS command set, comprehending what happens inside Cisco routers will help you as a network designer or engineer to perform your job more effectively. By understanding the internal operations of IOS Software, you will be able to take architectural considerations into account when designing networks and isolate problems more easily when troubleshooting networks. Inside Cisco IOS Software Architecture provides essential information on the internal aspects of IOS Software at this level, and it is an invaluable resource for better understanding the intricacies of IOS Software and how it affects your network.

Inide Cisco IOS Software Architecture begins with an overview of operating system concepts and the IOS Software infrastructure, including processes, memory management, CPU scheduling, packet buffers, and device drivers, as well as a discussion of packet switching architecture with detailed coverage of the various platform-independent switching methods, including process switching, fast switching, optimum switching, and Cisco Express Forwarding (CEF). The book then delves into the intricate details of the design and operation of platform-specific features, including the 1600, 2500, 4x00, 3600, 7200, 7500, and GSR Cisco routers. Finally, an overview of IOS Quality of Service (QoS) is provided, including descriptions of several QoS methods, such as priority queuing, custom queuing, weighted fair queuing, and modified deficit round robin.

Curtis Murphy, CCIE #1521, is an engineer in Cisco's Serviceability Design Department in Research Triangle Park, specializing in IOS software products. He has worked in the networking industry since 1989 and at Cisco since 1994. While at Cisco, he has worked both as an IBM protocols specialist in the Technical Assistance Center and as a software engineer in IOS Software Development for mid-range and high-end routers.

Russ White, CCIE #2635, is a member of the IOS Network Protocols Deployment and Scalability Team at Cisco, where he is involved in the design and implementation of routing protocols and scalable network design.

Vijay Bollapragada, CCIE #1606, is currently a manager in the Solution Engineering team at Cisco, where he works on new world network solutions and resolves complex software and hardware problems with Cisco equipment. Vijay also teaches Cisco engineers and customers several courses, including Cisco Router Architecture, IP Multicast, Internet Quality of Service, and Internet Routing Architectures. He is also an adjunct professor in Duke University's electrical engineering department.