Abstract: A method for facilitating communication in a Session Initiation Protocol (SIP) environment is provided that includes receiving, by a first endpoint, dialog and presence information associated with a second endpoint. The first and second endpoints are operable to conduct a SIP communication system. The method also includes identifying the dialog and presence information associated with the second endpoint.

Abstract: A system for inter-enterprise telephony communications includes a central brokerage device that can receive a packet encoding a dialed telephone identifier generated by a first telephony device located in the first enterprise network, where the dialed telephone identifier is associated with a second telephony device located in a second enterprise network. The central brokerage device can also identify a network address of the second enterprise network using connectivity information if the dialed telephone identifier matches resolution information. The system also includes the first enterprise network, which can establish an encrypted communication link with the second enterprise network through a packet-based network using the identified network address if the dialed telephone identifier matches the resolution information.

Abstract: A system for securing telephony communications between an enterprise telephony endpoint and a remote telephony endpoint includes an isolated packet-based network, an exposed packet-based network, and an isolation device. The isolated packet-based network has a plurality of enterprise telephony endpoints. The exposed packet-based network is coupled to a public packet-based network and has a call management device that can receive an unsecured session request from a remote telephony endpoint coupled to the public packet-based network, determine that the unsecured session request identifies one of the enterprise telephony endpoints, and establish a media link between the remote telephony endpoint and the isolation device.