If you place a Microsoft Exchange Server computer on a Fiber Distributed Data Interface (FDDI) ring with a 100 MB capacity, it provides better connectivity and performance than a server attached to a token-ring network. An overloaded Ethernet segment with many collisions occurring can also reduce the performance of a server. WAN connectivity and quality should also be considered, especially if you are trying to determine site boundaries or whether to give clients access to a server across the WAN.