Call processing arrangement for ATM switches

• US 6,563,835 B1
• Filed: 02/19/1999
• Issued: 05/13/2003
• Est. Priority Date: 02/20/1998
• Status: Expired due to Fees

• Current Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Chen, Xiaoqiang
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): PHAM, BRENDA H
• Application Number:
  US09/251,903
• Time in Patent Office: 1,544 Days
• Field of Search: 370/230, 370/235, 370/352, 370/356, 370/359, 370/360, 370/389, 370/395, 370/396, 370/428, 370/410
• US Class Current: 370/410
• CPC Class Codes: H04L 12/5601 Transfer mode dependent, e.g. ATM
• CPC Class Codes: H04L 2012/5629 Admission control
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 45/10 Routing in connection-oriented networks, e.g. X.25 or ATM
• CPC Class Codes: H04L 45/44 Distributed routing
• CPC Class Codes: H04L 49/1576 Crossbar or matrix
• CPC Class Codes: H04L 49/255 Control mechanisms for ATM switching fabrics
• CPC Class Codes: H04L 49/256 Routing or path finding in ATM switching fabrics

Abstract

A connection oriented switch, for example, an ATM switch, achieves scalable performance and enhanced reliability through a call processing architecture in which call processing functions are distributed to each network interface module rather than centralized in a call control module. Each network interface module has its own dedicated processor module that performs certain call processing tasks to off-load the processing burden from the call control module. Depending on the degree of processing power distribution, three embodiments include a distributed signaling architecture, a distributed call control architecture, and a distributed routing architecture.

Claims

1. A connection oriented switch with distributed signaling, said switch comprising:

a switching fabric,

a switch control module for providing (a) coordination of call processing tasks performed in said switch and (b) path selection for calls routed through said switch, said switch control module including a call control unit, a router determination unit under the control of said call control unit, and a topology database updated by a topology exchange, and

a plurality of interface modules, each including a signaling unit cooperative with said call control unit for (a) the decentralizing of at least one said call processing task from said switch control module, (b) directing said incoming calls from a source to said switching fabric and from said switching fabric toward a destination, (c) processing the signaling messages associated with said incoming calls in accordance with the signaling protocol stack terminated at said signaling unit, and (d) directing internal control messages associated with incoming calls to said switch control module, said internal control messages containing only necessary information used for call set up and path selection.

2. A connection oriented switch with distributed call control, said switch comprising:

a switching fabric,

a switch control module for providing path selection for calls routed through said switch, and

a plurality of interface modules, each including a call control unit, said interface modules arranged to (a) decentralize at least one call processing task from said switch control module, (b) direct said incoming calls from a source to said switching fabric and from said switching fabric toward a destination, (c) process the signaling messages associated with said incoming calls in accordance with the signaling protocol stack terminated at said interface modules, (d) coordinate among said interface modules, call control tasks performed in said switch, and (e) direct internal control messages associated with incoming calls directly to said call control unit in said outgoing interface modules, said internal control messages containing signaling and control primitives.

3. The invention defined in claim 2 wherein said interface modules are further arranged to query said switch control module to obtain information used to route calls through said switch.

4. The invention defined in claim 2 wherein said switch is an ATM switch and wherein said path selection is based upon the PNNI routing protocol.

5. A connection oriented switch with distributed routing, said switch comprising:

a switching fabric,

a switch control module containing a topology exchange unit that exchanges routing information with other switches in the network of which said connection oriented switch is a part,

a plurality of interface modules, each including a route determination unit, said interface modules arranged to (a) decentralize at least one call processing task from said switch control module, (b) direct said incoming calls from a source to said switching fabric and from said switching fabric toward a destination, (c) process the signaling messages associated with said incoming calls in accordance with the signaling stack protocol used by said switch, (d) coordinate among said interface modules, call control tasks performed in said switch, and (e) direct internal control messages associated with incoming calls to said call control unit in said outgoing interface modules, said internal control messages containing signaling and control primitives, and (f) provide path selection for calls routed through said switch in accordance with information contained in a topology database unit within said interface module, wherein topology information in said topology database is updated with information from said topology exchange unit located at said switch control module.

6. The invention defined in claim 5, wherein said switch is an ATM switch and wherein said topology database is constructed from information in said topology exchange unit in a format specified in the PNNI routing protocol.

7. The invention defined in claim 5 wherein said updates occur on a periodic and/or on an event-driven basis.