You can use H.323 Gatekeeper-Based Load Balancing to avoid the issue you are facing. After the call is rejected, the originating gateway must find another means of handling the call. There are several possibilities, most of which are dependent on the configuration of the gateway. In the absence of any specific configuration, the outgoing gateway will provide a reorder tone to the calling party. The reorder tone is called fast-busy in North America, and is known as overflow tone or equipment busy in other parts of the world. This tone is often intercepted by PSTN switches or PBXs with an announcement such as "All circuits are busy, please try your call again later."