Abstract: A distributed processing system (100) includes a protocol server (101) that enables a plurality of clients (103-104) to share the use of one set of Signaling System 7 (SS7) links (99), that centralizes the link-termination circuitry (110) for use by the plurality of clients, and that provides access to upper layers (215-219) of the SS7 protocol stack (200) by distributing the processing of different layers of the stack between the protocol server and the clients. The protocol server terminates the lower layers (210-213) of the SS7 protocol, while each client terminates the upper layers of the SS7 protocol. Communication between the protocol server and the clients of information expressed in the upper layers of the SS7 protocol is effected via the TCP/IP protocol over a LAN (102).

Abstract: In a private communication network (10) served by a provider of call interconnection services, e.g., a carrier service node (15), the number of trunks (50-52) used within a call path is reduced without affecting the private nature of the private network. The service provider serves customer calls by means of a service node controller (SNC 40)--a switch such as a PBX. The SNC directly interconnects trunks (50,51) that connect it with a call-source and a call-destination node (20,21) of the customer, without routing the call through the customer's tandem node (24). The SNC merely queries the customer's tandem node over a control link (53), such as an ISDN D channel, to obtain requisite call-routing information from the customer's database (60). The customer retains ownership and control of the tandem node and its database, thereby preserving the private nature of the private network.

Abstract: An arrangement is disclosed for providing station number portability to stations ported from an original switching node to a new switching node which allows the ported station to maintain its original assigned station number. A ported station retains its original assigned number when it's original and new node have a common data base. The common data base identifies what station number is currently associated with which node. The station can be ported from one node to another node by altering the data base to indicate the new association of the ported number and the node to which the station has been ported.

Abstract: In a private communication network (10) served by a provider of call interconnection services, e.g., a carrier service node (15), the number of trunks (50-52) used within a call path is reduced without affecting the private nature of the private network. The service provider serves customer calls by means of a service node controller (SNC 40)--a switch such as a PBX. The SNC directly interconnects trunks (50,51) that connect it with a call-source and a call-destination node (20,21) of the customer, without routing the call through the customer's tandem node (24). The SNC merely queries the customer's tandem node over a control link (53), such as an ISDN D channel, to obtain requisite call-routing information from the customer's database (60). The customer retains ownership and control of the tandem node and its database, thereby preserving the private nature of the private network.