Procedures for improving call routing in PNNI networks

摘要

A method and system for improving call routing in a PNNI network using crankback messaging. A destination logical group node (LGN) blocked crankback procedure is used by entry border nodes, in the event of a failed connection attempt, to instruct preceding routing capable nodes to route the connection over another link. If the entry border node is in the lowest level peer group a Succeeding End Blocked (SEB) crankback message is sent to the preceding routing capable node. If the entry border node is not in the lowest level peer group, a destination LGN blocked crankback message is sent to the preceding routing-capable node wherein the message has special information to signal the routing node that the link into the destination LGN is blocked.