The present invention describes how a trusted network routing authority,
such as a VoIP inter-exchange carrier or clearinghouse can provide
routing and secure access control across multiple network domains with a
single routing and admission request. This technology can improve network
efficiency and quality of service when an Internet Protocol (IP)
communication transaction, such as a Voice over IP (VoIP), must be routed
across multiple devices or administrative domains. This technology
defines the technique of performing multiple route look-ups at the source
of the call path to determine all possible routes across intermediate
domains to the final destination. The VoIP inter-exchange carrier or
clearinghouse then provides routing and access permission tokens for the
entire call path to the call source.