Method and apparatus for signaling over packet-based systems

Abstract

Signaling information is communicated over an ATM link or other packet-based communication link using packet headers. The information may be, for example, telephony signaling information such as an on-hook/off-hook indicator, a ring/no-ring indicator, or any other type of information used in establishing, maintaining, terminating or otherwise configuring a telephony-based communication. In an illustrative embodiment, a single bit of signaling information is incorporated into a low order bit of a packet type indicator field in a header of an ATM user data cell. This low order bit, which is generally used as an End of Message (EOM) indicator in a cell which is part of a multi-cell message, can be used to transmit the signaling information in packets corresponding to single-cell messages. For example, out-bound telephony signaling information may be received from a telephony device such as a telephone or a computer modem, incorporated into an ATM cell header of a single-cell voice sample message, transmitted over an ATM link, removed from the header in an ATM processing device, and delivered to a public switched telephone network. In-bound telephony signaling information may be received from the public switched telephone network, incorporated into an ATM cell header of a single-cell voice sample message, transmitted over an ATM link, removed from the header in an ATM processing device, and delivered to a telephony device.