An efficient interface for service exchange is provided between a circuit-switched communications network and a domain naming system (DNS) in a packet-switched communications network. A node in the circuit-switched communications network receives from a first entity a request for a first service involving...http://www.google.ca/patents/US6839421?utm_source=gb-gplus-sharePatent US6839421 - Method and apparatus to carry out resolution of entity identifier in circuit-switched networks by using a domain name system
