Deploying Technology in the Campus Infrastructure Module
Considering traffic source to destination path

The size of an enterprise network drives the design and placement of certain types of devices. If the network is designed according to the Enterprise Composite Network model, there will be distinct devices separating the access, distribution and backbone areas of the network. The network design and the types of applications supported will determine where certain traffic sources are located. In the case of multicast and IP telephony applications, they do share some common traffic types. Specifically, if a Cisco CallManager is providing music on hold, it may need to multicast that traffic stream. Similarly, if there is an IPTV broadcast server on the network it will also be sending information via multicast to a specific set of devices. Use these considerations when determining where to place the servers:

  1. IP multicast servers may exist within a server farm, or be distributed through the network at appropriately designed locations. Select distribution layer switches to act as rendezvous points and which are central to the location of the largest distribution of receiving nodes.
  2. Cisco CallManager servers must be accessible throughout the network at all times. Ensure redundant NICs in the publisher and subscriber servers and redundant connections between those NICs and the upstream switch from the server. It is recommended that voice traffic be configured on its own VLAN.
  3. VLAN trunks must be configured appropriately to carry IP telephony traffic throughout the network, or to specific destinations.