Understanding the network.pdf - Back to Home

The 4000 series routers come in a three-slot chassis, but they have
also been built in line card form to operate in Cisco's Catalyst 5000
switches and Cabletron's 9000 series switches. They support up to 18
Ethernet interfaces, 6 Token Ring, 2 Fast Ethernet, 2 FDDI, 1 HSSI, 34
Async Serial, 16 Sync Serial, and ATM. They run IOS 9.14 and higher.
The 7x00 (7000, 7200, and 7500) series routers make up Cisco's
high-end router line, and were Cisco's first generation of high-end
routers. The 7000 and 7010 originally used separate route and switch
(interface) processors. They now use a single processing unit called a
Route Switch Processor (RSP), and both models use Cisco's CxBus
architecture. The 7200 series routers are the mid-line enterprise
routers that use PCI bus architecture. The 7500 is the high end,
sporting the CyBus architecture. The 7x00 series routers'processing
speed is determined by the speed of the RSP (7000 and 7500) or
Network Processing Engine (NPE) (for the 7200). The 7x00 series
routers also support Cisco's Versatile Interface Processor (VIP), which
provides hot swap capability and Layer 2 switching capabilities. The
7x00 routers utilize IOS 11.x and higher, depending on the model.
Although it's not supported on every router platform, Cisco has a
Layer 2 implementation for each of the following:
• Ethernet (10, 100, and 1,000Mbps)
• Token Ring (4 and 16Mbps)
• Asynchronous Serial (11,500Bps)
• Synchronous Serial (DS0, DS3)
• HSSI (High Speed Serial Interface)
• ISDN (BRI and PRI)
• ATM (DS3, 0C3)
• POS (0C3, 0C12)
Memory on Cisco Routers
Everything about Cisco routers revolves around memory. Memory is
used to boot the router, store its operating system, perform the
routing process, and store the router's configuration information. To
perform these tasks, four types of memory are used:
• Read-only memory (ROM)
• Flash memory
• Non-volatile random access memory (NVRAM)
• Dynamic random access memory (DRAM)