Method and apparatus for distributed MTP Level 2 architecture

• US 6,687,251 B1
• Filed: 12/08/1999
• Issued: 02/03/2004
• Est. Priority Date: 12/08/1999
• Status: Expired due to Term

• Current Assignee: Ribbon Communications Operating Company, Inc. (Ribbon Communications, Inc.)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Yoakum, John H., Mousseau, Guy G.
• Primary Examiner(s): Ngo, Ricky
• Assistant Examiner(s): HA, YVONNE QUY M
• Application Number:
  US09/456,560
• Time in Patent Office: 1,518 Days
• Field of Search: 370/352-356, 370/401, 370/402, 370/410, 370/466, 370/467, 370/465, 379/229, 379/230, 379/88.17
• US Class Current: 370/401
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• CPC Class Codes: H04M 7/06 using auxiliary connections for control or supervision , e.g. where the auxiliary connection is a signalling system number 7 link
• CPC Class Codes: H04M 7/125 Details of gateway equipment
• CPC Class Codes: H04Q 3/0025 Provisions for signalling

Abstract

An apparatus and method for distributing the SS7 Message Transfer Part Level 2 (MTPL2) between a Media Gateway and a Signalling Gateway in a Voice over IP Switch is disclosed. The distribution of the MTP Level 2 stack allows data links in a fully associated SS7 network to be terminated on the Media Gateway and SS7 messages to be exchanged between the Media Gateway and the Signalling Gateway over an IP backbone.

Claims

1. A method providing distributed Message Transfer Part (MTP) functionality over an Internet Protocol (IP) network, said method comprising:

at a first media gateway;

receiving conventional MTP signaling units from a first network element;

removing repeated MTP signaling units from said MTP signaling units received;

either before or after said removing, encapsulating received MTP signaling units into data packets to form a reduced signaling unit packet stream; and

transmitting said reduced signaling unit packet stream to a signaling gateway;

receiving at said signaling gateway said reduced packet stream at said signaling gateway;

transmitting packets encapsulating MTP signaling units to one of said first media gateway and a second media gateway, said transmitted packets being responsive to said received reduced signaling unit packet stream;

receiving at said one of said first media gateway and said second media gateway said packets transmitted by said signaling gateway; and

at said one of said first media gateway and said second media gateway, re-creating conventional MTP signaling units based on said routed packets and transmitting said re-created conventional MTP signaling units to one of said first network element and a second network element.

2. The method of claim 1 wherein each of said packets comprises:

a packet header;

a Message Transfer Part Level 2 (MTPL2) header;

a distributed level two protocol header; and

a payload, said payload corresponding to conventional MTPL2 signaling units.

3. The method of claim 2 wherein each of said packets is an Internet Protocol (IP) and said packet header comprises:

an IP header; and

a UDP header.

4. The method of claim 3 wherein said each of said IP packets further comprises:

a length indicator indicating the length of the entire IP packet; and

a checksum field generated based on the uncorrupted values stored in the IP packet.

5. The method of claim 3 wherein said IP header comprises a source IP address and a destination IP address and said UDP header comprises a UDP header length indicator, a source port field, a destination port field and a length indicator indicating the length of said each of said IP packets.

6. A Voice over Internet Protocol (VoIP) switch providing a distributed Message Transfer Part Level 2 (MTPL2) protocol, said VoIP switch comprising:

a plurality of media gateways, each of said media gateways in communication with a conventional SS7 physical link, said conventional SS7 physical link in communication with a network element, each of said media gateways further comprising;

an SS7 receiver receiving conventional SS7 signaling units and interfacing with said conventional physical link;

an SS7 transmitter for transmitting conventional SS7 signaling units from said media gateway to a network element over said conventional physical link;

an IP transmitter for forming and transmitting IP packets corresponding to conventional SS7 signaling units complying with Message Transfer Part Level Two (MTPL2) protocol, said IP packets being transmitted over said IP network to said signaling gateway; and

an IP receiver for receiving IP packets corresponding to conventional SS7 signaling units complying with said MTPL2 protocol, said IP packets being received from said IP network from said signaling gateway;

a signaling gateway, said signaling gateway comprising;

an IP transmitter for routing IP packets corresponding to conventional SS7 signaling units complying with Message Transfer Part Level Two (MTPL2) protocol, said IP packets being transmitted over said IP network to one of said media gateways;

an IP receiver for receiving IP packets corresponding to conventional SS7 signaling units complying with said MTPL2 protocol, said IP packets being received from said IP network from one of said media gateways; and

a controller controlling the functions of said signaling gateway and said media gateways; and

an IP network providing IP communication between said plurality of media gateways and said signaling gateway.

7. The VoIP switch of claim 6 wherein each of said media gateways further comprises a processor, said processor adapted to:

generate IP packets encapsulating signaling units received by said SS7 receiver; and

generate conventional SS7 signaling units responsive to IP packets received by said IP receiver.

8. The VoIP switch of claim 7 wherein said IP packets generated by said processor comprise:

an IP header;

a UDP header;

a distributed level two protocol header;

a Message Transfer Part Level 2 (MTPL2) header; and

a payload, said payload corresponding to a conventional SS7 signaling unit.

9. The VoIP switch of claim 8 wherein said stream has a length such that for a stream of identical Fill-In Signaling Units (FISUs) or Link Status Signal Units (LSSUs) greater than said length one signaling unit is sent in an IP packet periodically.

10. The VoIP switch of claim 8 wherein said processor is further adapted to, for a data stream formed of a plurality of identical Fill-In Signaling Units (FISUs) or for a data stream formed from a plurality of identical Link Status Signal Units (LSSUs) received from said SS7 receiver, encapsulate only one signaling unit in an IP packet representative of said contiguous stream for transmission between said media gateway and said signaling gateway.

11. The VoIP switch of claim 10 wherein said processor is further adapted to, for an IP packet representative of a contiguous stream of FISUs or LSSUs received by said IP receiver, generate a plurality of identical conventional SS7 signaling units representative of said FISUs or LSSUs received from said SS7 receiver in response to an instruction received from said signaling gateway, said plurality of conventional signaling units transmitted by said SS7 transmitter of said media gateway.