Cisco 7200 Routers

The 7200 router has been one of the most common Cisco routers found in networks. Because of it’s modular design, Cisco have been able to continually upgrade and improve it’s capacity and performance.

The 7200 router consists of a chassis that can hold dual power supplies, a single route processor card, and up to six additional interface cards.

The number of additional slots depends on the model (7202 has two slots, 7204 has four etc)

7200 router chassis come in two versions - original and VXR. The original chassis was designed for use with NPE-100, NPE-150, NPE-200 and NPE-225 route processor cards. The original 7206 backplane is supposed to support up to 500 KBPS.

The VXR is a more powerful model and has a 1 Gbps midplane. It supports more powerful processor cards such as the NPE-300, NPE-400 and the NPE-G1. These cards are not compatible with the older chassis.

When installing cards into a 7200, there are clear guidelines as to the order in which slots should be used, in order to maximise the available backplane bandwidth. The bandwidth is divided between two pci buses that are used to connect left and right hand cards. The available bandwidth is split between the left and right slots on the chassis. Cisco uses a system of bandwidth points, whereby the different types of interface cards have a bandwidth points value. For instance a PA-A3-OC3 card has a value of 300 points. On a 7206VXR router, the total bandwidth points for the either the left or right-hand side slots must not total more than 600 points. The bandwidth points should be evenly distributed between the left and right slots.

The route-processor cards are easily the most expensive part of the unit. The processor card slots into the back of the 7200, below the power supplies. Usually a I/O controller card is inserted opposite this facing the front of the unit. The I/O controller card usually holds the PCMCIA clot, the console port and some ethernet interfaces. On the latest cards (NPE-G1 and NPE-G2), the PCMICA slot, console port and gigabit ethernet interfaces are actually on the processor card itself.

The old 7200’s are still good routers, but the early cards are quite limited in the amount of memory that they support. With a NPE-225 card they can support up to 256mb RAM, so can hold a sizeable routing table. Cisco says that a NPE-225 can support up to 225 Kpps. Not so sure about that.

The VXR’s can support much more powerful cards. The NPE-400 can accomodate 512mb RAM, and 400kpps. Additionally, cards like the NPE-G1 and NPE-G2 have multiple gigabit ethernet ports, so traffic switch across the card does not touch the backplane. Therefore, these interfaces do not count as part of the interface ‘bandwidth points’ on the router. The NPE-G1 and NPE-G2 can support 1gb RAM, and handle up to 1 million and 2 million pps respectively.

Cisco also developed an NSE-1 card for the 7200VXR. This card has an additional Parallel eXpress Forwarding (PXF) processor. These cards do not work with all IOS versions. Cisco appear to have abandoned this line of development for the 7200 series.

Cisco have released a 1u version of the 7200. The 7201 has an in-built route processor card, and four gigabit ethernet ports. It has a single additional interface card slot.