Method and apparatus for ATM address resolution

• US 20010043604A1
• Filed: 04/12/2001
• Published: 11/22/2001
• Est. Priority Date: 04/25/1997
• Status: Active Grant

• Current Assignee: Ericsson AB (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Northern Telecom Limited (Nortel Networks Corporation)
• Inventors: Li, Li, Mistry, Nalin, Morris, Todd Douglas
• Granted Patent: US 7,075,931 B2
• Time in Patent Office: Days
• US Class Current: 370/395.7
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• CPC Class Codes: H04L 2012/563 Signalling, e.g. protocols, reference model
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections

Abstract

In a generic, end-to-end address resolution methodology, destination addresses in one format are translated into local addresses of different formats for purposes of routing calls across a plurality of interconnected networks which use different address formats. Translation of addresses is accomplished through either database query or by conversion algorithm. To facilitate routing across a particular network, the signaling message of the call is repacked with the local address as the routing address. The original destination address is preserved and carried transparently across that network. The signaling message is then repacked with the destination address as the routing address. Bi-level addressing schemes are supported, so that a network-level destination address and user-level destination address may both be carried transparently across a particular network.

Claims

1. A method for routing a call across a first ATM network toward a second ATM network, each network having an addressing format, the addressing format of the first network being different from the addressing format of the second network, the call having an associated signaling message specifying a destination address in the second network, the method comprising the steps of:

translating the destination address into a local address in the addressing format of the first network;

repacking the signaling message with the local address as a routing address;

routing the call through the first network using the local address; and

repacking the signaling message with the destination address as the routing address.

2. The method of

claim 1

further comprising the step of

forwarding the call toward the second network.

3. The method of

claim 1

wherein the step of translating the destination address into a local address includes the substep of

querying an address translation database populated with an address interface identifier pair to obtain the local address.

4. The method of

claim 1

wherein the step of translating the destination address into a local address includes the substep of

querying an address translation database populated with an address interface identifier pair to obtain the local address, wherein the interface identifier pair specifies as the local address the address of an egress port in the first network.

5. The method of

claim 1

wherein the step of translating the destination address into a local address includes the substep of

querying an address translation database populated with an address interface identifier pair to obtain the local address, wherein the interface identifier pair specifies as the local address the address of an egress port in the first network and specifies the destination address, and wherein the local address corresponds to the destination address such that routing the call to the local address causes the call to be routed toward the second network.

6. The method of

claim 1

wherein the step of translating the destination address into a local address includes the substep of

applying a conversion algorithm to the destination address to obtain the local address.

7. The method of

claim 1

wherein the step of translating the destination address into a local address includes the substep of

applying a conversion algorithm to the destination address to obtain the local address, wherein the local address corresponds to the destination address such that routing the call to the local address causes the call to be routed toward the second network.

8. The method of

claim 1

wherein the step of routing the call through the first network includes the substep of

carrying the destination address transparently across the first network.

9. The method of

claim 8

, wherein the signaling message further specifies a destination address in an end system beyond the second network, and wherein the step of routing the call through the first network further includes the substep of

carrying the end system destination address transparently across the first network.

10. The method of

claim 8

, wherein the signaling message further specifies a destination address in an end system beyond the second network, wherein the destination address is a network-level address and the end system destination address is a user-level address, and wherein the step of routing the call through the first network further includes the substep of

carrying the end system destination address transparently across the first network.

11. The method of

claim 1

wherein the step of repacking the signaling message with the local address includes the substeps of

demoting the destination address from a first signaling message parameter to a second signaling message parameter;

and

inserting the local address into the first signaling message parameter.

12. The method of

claim 11

wherein the step of repacking the signaling message with the destination address includes the substeps of

discarding the local address from the first signaling message parameter;

and

promoting the destination address to the first signaling message parameter.

13. An apparatus for use in routing a call across a first ATM network toward a second ATM network, each network having an addressing format, the addressing format of the first network being different from the addressing format of the second network, the call having an associated signaling message specifying a destination address in the second network, the apparatus comprising:

an address resolution server for translating the destination address into a local address in the addressing format of the first network;

means for repacking the signaling message with the local address as a routing address;

means for routing the call through the first network using the local address; and

means for repacking the signaling message with the destination address as the routing address.

14. The apparatus of

claim 13

further comprising

means for forwarding the call toward the second network.

15. The apparatus of

claim 13

wherein the address resolution server includes

means for querying an address translation database populated with an address interface identifier pair to obtain the local address.

16. The apparatus of

claim 13

wherein the address resolution server includes

means for querying an address translation database populated with an address interface identifier pair to obtain the local address, wherein the interface identifier pair specifies as the local address the address of an egress port in the first network.

17. The apparatus of

claim 13

wherein the address resolution server includes

means for querying an address translation database populated with an address interface identifier pair to obtain the local address, wherein the interface identifier pair specifies as the local address the address of an egress port in the first network, and wherein at least one interface identifier pair further specifies the destination address, the local address corresponding to the destination address such that routing the call to the local address causes the call to be routed toward the second network.

18. The apparatus of

claim 13

wherein the address resolution server includes

means for applying a conversion algorithm to the destination address to obtain the local address.

19. The apparatus of

claim 13

wherein the address resolution server includes

means for applying a conversion algorithm to the destination address to obtain the local address, wherein the local address corresponds to the destination address such that routing the call to the local address causes the call to be routed toward the second network.

20. The apparatus of

claim 13

wherein the means for routing the call through the first network includes

means for carrying the destination address transparently across the first network.

21. The apparatus of

claim 20

, wherein the signaling message further specifies a destination address in an end system beyond the second network, and wherein the means for routing the call through the first network further includes

means for carrying the end system destination address transparently across the first network.

22. The apparatus of

claim 20

, wherein the signaling message further specifies a destination address in an end system beyond the second network, wherein the destination address is a network-level address and the end system destination address is a user-level address, and wherein the means for routing the call through the first network further includes

means for carrying the end system destination address transparently across the first network.

23. The apparatus of

claim 13

wherein the means for repacking the signaling message with the local address includes

means for demoting the destination address from a first signaling message parameter to a second signaling message parameter;

and

means for inserting the local address into the first signaling message parameter.

24. The apparatus of

claim 23

, wherein the means for repacking the signaling message with the destination address includes

means for discarding the local address from the first signaling message parameter;

and

means for promoting the destination address to the first signaling message parameter.

25. A communications network comprising:

a first ATM network interconnected to a second ATM network, each network having an addressing format, the addressing format of the first network being different from the addressing format of the second network, the first network handling a call having an associated signaling message specifying a destination address in the second network, the first network including;

an address resolution server for translating the destination address into a local address in the addressing format of the first network;

means for repacking the signaling message with the local address as a routing address;

means for routing the call through the first network using the local address; and

means for repacking the signaling message with the destination address as the routing address.

26. The communications network of

claim 25

further including

means for forwarding the call toward the second network.

27. The communications network of

claim 25

wherein the means for routing the call through the first network includes

means for carrying the destination address transparently across the first network.

28. The communications network of

claim 25

wherein the means for repacking the signaling message with the local address includes

means for demoting the destination address from a first signaling message parameter to a second signaling message parameter;

and

means for inserting the local address into the first signaling message parameter.

29. The communications network of

claim 28

wherein the means for repacking the signaling message with the destination address includes

means for discarding the local address from the first signaling message parameter;

and

means for promoting the destination address to the first signaling message parameter.

30. A method for routing a call in a communications network, the communications network comprising a first ATM network interconnected to a second ATM network, each network having an addressing format, the addressing format of the first network being different from the addressing format of the second network, the first network handling a call having an associated signaling message specifying a destination address in the second network, the method comprising the steps of:

translating the destination address into a local address in the addressing format of the first network;

repacking the signaling message with the local address as a routing address;

routing the call through the first network using the local address; and

repacking the signaling message with the destination address as the routing address.

31. The method of

claim 30

further comprising the step of

forwarding the call toward the second network.

32. The method of

claim 30

wherein the step of routing the call through the first network includes the substep of

carrying the destination address transparently across the first network.

33. The method of

claim 30

wherein the step of repacking the signaling message with the local address includes the substeps of

demoting the destination address from a first signaling message parameter to a second signaling message parameter;

and

inserting the local address into the first signaling message parameter.

34. The method of

claim 33

wherein the step of repacking the signaling message with the destination address includes the substeps of

discarding the local address from the first signaling message parameter;

and

promoting the destination address to the first signaling message parameter.