CAC Internet Rerouting

When a bandwidth policy limit is exceeded by a user, Call Admission Control kicks in with an attempt to reroute the call. First, the call attempts to be directed over the Internet if both sites have an Edge Server. Instead of using the WAN link, the call traverses the Internet and is relayed between the Edge Servers in each site. If that is not possible or fails, the call can reroute across the PSTN. Whether this is allowed depends on whether the voice policy assigned to the user allows this feature. If neither Internet nor PSTN rerouting is possible, the call attempts to be sent directly to voice mail. Lastly, if voice mail is unavailable, the call simply fails.

Figure 32.9 demonstrates how the Internet rerouting feature works between two sites with Edge Servers.

Figure 32.9. A/V Edge Internet reroute.