Third party call control and status signaling

摘要

Aspects relate to call control by third parties, where IP or a similar transport is used over a part of the channel for a given call and circuit-switched signaling protocols are used on a different part. For example, a PBX can communicate using SIP signaling to a gateway to a PSTN network, to which a Public Land Mobile Network (PLMN) is coupled, and which a mobile device, uses for voice communication. Controlling or updating status in these kinds of situations can be accomplished by forming a Q.931/932 message, such as a FACILITY message, which has fields (Information Elements) for pre-defined purposes (other than third party call control), and providing control or status information in such field(s). The message (the info) is tunneled through the gateway and the network(s), and arrives at its destination device. That device determines that a field does not comport with a valid format interpretation, and on that basis, can determine that the field has contents to be interpreted as call control or status information.

主权项

1. A telephony system, comprising:
a mobile device with a telephony client responsive to signaling messages of one or more signaling protocols, each signaling message having one or more pre-defined fields received during an ongoing voice communication session, the response including determining whether a received signaling message includes a pre-defined field updated with data, wherein the data is consistent with a standard definition of the field but is undefined according to the standard definition of the field, and is portable across at least two telecommunication signaling formats, and responsive to the determining, interpreting the data in the pre-defined field as control information for use in the ongoing voice communication session using a pre-arranged signaling convention; and a server with a telephony control module for:
determining that a signaling message is to be carried using the pre-arranged signaling convention of the ongoing voice communication;in response to the determination, forming the signaling message according to the one or more signaling protocols, the forming respectively comprising providing the pre-defined field with data in the signaling message, indicative of control information, in a format that is consistent with the standard definition of the field but is undefined according to the standard definition of the field, wherein the server is coupled to an Internet Protocol (IP) network capable of tunneling the signaling messages to a network, for reception by the mobile device.