Providing feature transparency between a plurality of PBXs

摘要: An arrangement for according station and attendant feature transparency between independently operational PBXs of a PBX network. Each includes switch processor, lines tie-trunks extending to other PBXs. also has Direct Memory Data Controller (DMDC) transmitting service or related data messages associated with tie-trunk calls over links. On an interPBX call, the DMDC in calling transmits message called direct link In event there is no PBXs, at tandem which, turn, sends PBX. The processes received and, by memory access, its processor which provides specified required on call above beyond establishment voice path connection stations. This allows appear customers as if they are served single large