Abstract: Narrowband signaling from a transfer node for a call originating at an end office is received at a centralized control and signaling interworking function device in an asynchronous transfer mode switching network. The received narrowband signaling is converted to broadband signaling. The broadband signaling is provided to a plurality of trunk interworking function devices via the asynchronous transfer mode switching network, to establish a connection across the asynchronous transfer mode switching network, when the centralized control and signaling interworking function device and the plurality of trunk interworking function devices are determined to be members of a closed user group.

Abstract: A method for providing secure communications through a communications network comprising ATM channels and TDM channels. The communications network includes at least one closed user group of network elements configured to communicate with only other network elements in the closed user group. The method receives a connection setup request at an ingress ATM switch, via a UNI attached to the ATM switch, in response to a call initiated through a TDM channel. The UNI interfaces a first network element of the closed user group with the ATM switch. The method further verifies that an ATM End System Address (AESA) contained in calling party information of the connection setup request is consistent with the attached UNI. Additionally, the method establishes a connection with at least a second network element of the closed user group through an egress ATM switch in the communications network when the AESA is consistent with the attached UNI.

Abstract: A method for providing secure communications through a communications network comprising ATM channels and TDM channels. The communications network includes at least one closed user group of network elements configured to communicate with only other network elements in the closed user group. The method receives a connection setup request at an ingress ATM switch, via a UNI attached to the ATM switch, in response to a call initiated through a TDM channel. The UNI interfaces a first network element of the closed user group with the ATM switch. The method further verifies that an ATM End System Address (AESA) contained in calling party information of the connection setup request is consistent with the attached UNI. Additionally, the method establishes a connection with at least a second network element of the closed user group through an egress ATM switch in the communications network when the AESA is consistent with the attached UNI.

Abstract: A system and method for ensuring security in a voice trunking over ATM (VTOA) environment is provided. A telecommunications network is provided that carries control traffic and bearer traffic via ATM communications channels and TDM communications channels. The telecommunications network includes at least one closed user group consisting of multiple closed user group members. The closed user group members include trunk interworking function (T-IWF) devices configured to receive end office voice trunks from TDM channels and convert the trunks to ATM cell streams and to receive ATM cell streams and convert the ATM cell streams to end office voice trunks; and at least one centralized control and signaling interworking function (CS-IWF) device. The CS-IWF device performs call control functions and interfaces narrowband and broadband signaling for call processing and control within the ATM switching network. The closed user group members also includes a VTOA switch management system (SMS).