When an intelligent VoIP endpoint terminal on a VoIP network becomes
inoperative for any reason and can't respond to a service request that it
had been programmed for, rather than leaving that service request
unfulfilled, a VoIP network-hosted instance of that primarily endpoint
terminal-provided service is invoked to handle that request and provide
the service that would have otherwise been provided by the endpoint
terminal. The network-hosted instance thus executes the requested service
on behalf of the unavailable endpoint terminal.