Method of address resolution for the transfer of synchronous transfer mode calls through multiple domains in a broadband data network

Abstract

A method of address resolution for the transfer of voice and voice data calls through multiple domains in a broadband data network is described. The implementation of broadband data networks as transport backbones for voice and voice data calls requires address resolution to determine the destination node for each call. Because of the projected frequency at which new access peripherals will be added to such broadband data networks, manual maintenance of translation tables is impractical. The invention therefore provides an automated method for address resolution which permits voice interface control units associated with the broadband data network nodes to automatically maintain the required translation tables. Next-hop resolution routing tables may be maintained at every node or only at nodes designated as signaling gateways between broadband data network domains. If the broadband data network is an ATM network, switched virtual circuits are set up in reverse from ATM destination nodes in order to reduce call admission and setup time. The advantage is automated maintenance of translation tables which may be tailored to meet the operating policy of network managers that control respective domains.

We claim:  
     
         1 . A method of address resolution for the transfer of synchronous transfer mode (STM) calls through multiple domains in an IP network, comprising the steps of: 
 checking a called number translation table at an edge node in the IP network which receives an admission request for the call to determine whether an address of an IP destination node to serve the called number is known;    if the address is known, sending IP packets to the destination node to set up egress of the call from the destination node to the STM network;    if the address is not known, formulating a query message at the edge node to determine the address of an IP destination node that serves the called number; and    forwarding the query message to at least one predetermined node in the IP network to request a translation of the called number to determine the address of the IP destination node; and    for a predefined number of hops, forwarding the query message to at least one other IP node if a node receiving the query does not possess information to enable the translation.    
     
     
         2 . A method as claimed in  claim 1  wherein the at least one predetermined node in the IP network is a gateway node in the domain of the edge node.