Dial Plan Considerations

Configuring a dial plan for MGCP is fairly simple, because the call agent handles all the call control information in normal circumstances. Dial plans are configured on the call agent. Dial peers must still be configured for analog or PSTN digital ports, such as FXO, FXS, or PRI. However, these dial peers are associated withand controlled bythe CallManager.

If the gateway falls back to H.323 when its connection to the CallManager is lost, you must plan the routing of calls during fallback. Typically, all calls are forwarded to the PSTN in this circumstance, but occasionally they are forwarded to a different gateway instead. If you want this operation to be transparent to your users, you might need to add digits such as area or long-distance access codes. If you will use the router in SRST mode, you might need other configurations to emulate CallManager capabilities. Chapter 13, "SRST and MGCP Gateway Fallback," details these.