The diameter of a network is the longest route that any packet would have to take in traveling from one host to another. This route is measured in hops, or number of wires between hosts. In a broken token ring, the diameter is N-1, because in the worst case, the two computers at the ends of the chain would have to send packets through each wire in the chain to reach each other. In a bus, the diameter is 1 since there is only one wire between any two hosts.

If two wires go down in a token ring, then some hosts will no longer be able to talk to other hosts. We call this a partition of the network and it obviously is a very bad thing. However, hosts within each section of the network probably still can talk to others. Fig. 23.11.4 shows a token ring with two breaks causing a partition of size 2.