In order to meet the bandwidth needs of existing and future applications, all campus infrastructure designs should incorporate a switched architecture. More efficient use of Class C IP address spaces may be achieved using variable length subnet masking or with IP virtual subnets. However, since IP telephones do not require access to the Internet, the use of private IP addresses may prove to be a valuable tool for conserving IP addresses when using IP telephones. Advanced network services such as policy based management, and global directory services should be supported. Given the use of IP and ATM, support for LANE or MPOA should be considered.
Colleges are free to use the most appropriate routing protocol for their environment.
The only requirement is that the selected routing protocol broadcast all of the subnet Ids that support users who require Internet access into the network, so that the users will have WAN connectivity. The migration plan should allow the switched backbone to be put in place first, and then move groups of users in a way that is most efficient for the college. The bandwidth requirements for the end devices are then aggregated to determine the upstream bandwidth requirements for each of the lines connecting the work group switches to the infrastructure switches above them. Using a worst-case analysis for each element in the infrastructure is the only way to ensure that each end device will be provided with enough bandwidth to meet its needs. The design of the physical infrastructure must be developed first.