ISDN terminal equipment-resident mechanism for automatically determining service profile identifiers (SPIDS) for subdivided area code

摘要

An auto-SPID detection routine is operative to conduct an iterative search of stored SPID formats associated with different central office switch protocols, based upon directory information including an area code supplied by a user. If an attempt to register a SPID is successful, the routine places a test call. If the test call is successful, the SPID and its associated switch protocol will have been identified, and the terminal equipment may place a call. If an attempt to register a SPID is unsuccessful, a determination is made as to whether the area code is a subdivided or split area code. If so, the routine is reexecuted using another area code derived from a split area code table.