System and method for utilizing direct user signaling to enhance fault tolerant H.323 systems
An H.323 client terminal ( 102 ) according to an embodiment of the invention employs primary and secondary H.323 control units or state machines ( 110 a , 110 b ). The primary control unit ( 110 a ) sends signaling messages to a primary gatekeeper ( 108 a ) and triggers the secondary control unit ( 110 b ) to send a message with an appropriate correlation identifier directly to a second client terminal. The primary control unit ( 110 a ) establishes a call per standard H.323 protocols. The secondary control unit ( 110 b ) also establishes a direct signaling connection to the second client terminal as back up. However, no media channels are established for this backup signaling. The secondary control unit ( 110 b ) checks the status of the call with the primary control unit ( 110 a ). If the call signaling on the primary control unit ( 110 a ) is proceeding normally, no further action is taken. If the call signaling with the primary gatekeeper ( 108 a ) fails, the secondary control unit ( 110 b ) takes over the signaling communication via the direct signaling channel.
1. A telecommunications method, comprising:
establishing a primary signaling connection in a packet-switched network between a first client terminal and at least one second client terminal;
establishing a secondary redundant signaling connection in said packet-switched network between said first client terminal and said at least one second client terminal;
establishing a single packet-switched media connection between said first client terminal and said at least one second client terminal while said primary signaling connection and said secondary redundant signaling connection are ongoing, signaling for said single media connection being provided by said primary signaling connection; and
maintaining said single media connection using said secondary redundant signaling connection if said primary signaling connection fails.
2. A telecommunications method in accordance with claim 1 , wherein said primary signaling connection is via a first gatekeeper.
3. A telecommunications method in accordance with claim 2 , further comprising re-establishing a second primary signaling connection via a second gatekeeper if said primary signaling connection via said first gatekeeper has failed, while maintaining said secondary redundant signaling connection and while said media connection is ongoing.
4. A communication client terminal for use in a packet-switched network having separate signaling and media channels, comprising:
a first controller configured to handle call signaling over a first connection during a packet-switched media communication with another client terminal;
a second controller configured to handle call signaling over a second connection directly with said another client terminal;
wherein said second controller provides redundant signaling for said media connection while said media connection is ongoing and while said first controller provides call signaling for said media connection, and said second controller provides said call signaling for said media connection directly if said first connection fails.
5. A communication client terminal as recited in claim 4 , wherein said first signaling connection is via a gatekeeper.
6. A telecommunications system, having separate media and signaling channels, comprising:
a packet-switched network;
a plurality of client terminals coupled to said packet switched network;
wherein the plurality of client terminals are configured to establish primary signaling connections with one another and redundant signaling connections with one another directly while maintaining a single media connection such that if said primary signaling connections fail, said media connection is maintained with said redundant signaling connection during a search for a back-up primary signaling connection.
7. A telecommunications system according to claim 6 , wherein said primary signaling connection is via a first gatekeeper.
8. A telecommunications system according to claim 7 , wherein said search is for a back-up gatekeeper if said first gatekeeper fails while a signaling channel is maintained by said redundant signaling connection.