Ethernet Connectivity

What is Ethernet?

Ethernet is the standard wire protocol used at Carnegie Mellon for networking of all platforms. Delivered via Category-5 Unshielded Twisted Pair (Cat-5 UTP) wire, our access layer infrastructure is composed of Cisco 1900, 2800, 2900, and 3500 switches, as well as legacy Bay Networks Managed Hubs. These combine to provide access to users at speeds of 10Mbps shared, 10Mbps switched, and 100Mbps switched (Fast Ethernet.)

Ethernet Networking

Many machines today come with built-in Ethernet capabilities, however it is easy to purchase an ethernet adapter for all common platforms. Prices vary, but the Carnegie Mellon Computer Store can help you select an appropriate model.

Some areas of campus require the use of a balun (or media adapter) to convert from the standard RJ-45 Cat-5 UTP jack to the somewhat different IBM outlet. These are available from the Computer Store. Although you can only connect a single machine directly to your outlet, it is possible for you to purchase a hub or switch to connect multiple devices to a single activated outlet. Note, however, that if any machine on an outlet is causing network troubles, all machines on the outlet may temporarily lose network connectivity.

Outlet Activation

Activation of a new outlet on campus requires registration of the outlet through NetReg and payment of an activation fee. Please contact the Carnegie Mellon Computer Store for a current fee schedule. The registration fee is assessed to cover the cost of network switches and other infrastructure.

If you have a temporary need for a connected outlet, please contact advisor@andrew.cmu.edu. Note that many public locations and meeting rooms have AuthBridge NetBar outlets, which allow immediate access upon registration.

Benefits of Switched Connections

With shared 10base-T or 100base-T, all traffic coming from or going to any machine on your segment will be on your connection, thus lowering your maximum connection speed. With switched 10base-T, the 'switch' will only put traffic on your connection that you need to see. Extraneous traffic is eliminated.

Connection Instructions

Computing Services has extensive documentation on the procedures for connecting your machine to the campus ethernet network.