Name resolution protocol, system and method for resolving a flat name space to an address space

• US 6,738,828 B1
• Filed: 07/06/2000
• Issued: 05/18/2004
• Est. Priority Date: 07/06/2000
• Status: Expired due to Fees

• Current Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Barry, Peter J., Corkum, Trevor D., Keats, Bruce D.
• Primary Examiner(s): LE, HIEU C
• Application Number:
  US09/611,943
• Time in Patent Office: 1,412 Days
• Field of Search: 709/227-229, 709/245, 709/204, 709/205, 709/238-239, 370/270, 370/264, 370/257, 370/475, 370/465-466, 370/351-354, 370/401-402
• US Class Current: 709/245
• CPC Class Codes: H04L 12/42 Loop networks
• CPC Class Codes: H04L 45/742 Route cache; Operation thereof
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/10 of different types

Abstract

Networks, network elements and methods providing a name resolution protocol which performs name resolution from a flat name space, such as the TL1 name space, to an address space, such as the IP address space are provided. Request functionality involves processing a requested name by determining if the requested name is the local name or a name of a previously resolved name-to-address mapping, and if not by sending a request message to a group of network elements which have joined the group, the request message containing the requested name for which a corresponding address is required. The group of addresses might for example be a multicast group of IP addresses. The reporting functionality involves responding to requests generated as outlined above and consists of joining a group of addresses, and processing the request message containing a requested name for which a corresponding address is required by comparing the requested name with the local name, and if there is a match, to reply with a response message specifying the local address. In embodiments employing the IP address space, the network elements have a stack interface between IP packets and physical layer frames which might for example be SONET frames. The stack interface might for example be adapted to insert the IP packets in a channel defined by predetermined byte locations in the physical layer frames. In the event the physical layer frames are SONET frames, such predetermined byte locations might for example be SONET D1 to D12 overhead bytes.

Claims

1. A network element adapted to perform address resolution from a flat name space to an address space, the network element comprising:

a first memory element adapted to store at least one local name of the network element, each local name belonging to a respective flat name space;

a processing element adapted to process a requested name by determining if the requested name is one of the at least one local names, and if not to send a request message to a group of network addresses in the address space belonging to network elements which have joined the group, the request message containing the requested name for which a corresponding address is required.

2. A network element according to claim 1 further comprising a second memory element adapted to store previously resolved name-to-address mappings;

wherein the processing element is adapted to process the requested name by determining if the requested name is one of the at least one local names or a name of a previously resolved name-to-address mapping, and if not to send the request message.

3. A network element according to claim 2 further adapted to receive a response message specifying a particular network address for the requested name, and to add a name-to-address mapping to the second memory element identifying the particular network address as being the network address for the requested name.

4. A network element according to claim 2 further comprising:

a third memory element adapted to store a local address;

a procedure by which the network element joins the group of network addresses;

a request message processing element adapted to process a received request message containing a requested name for which a corresponding address is required by comparing the requested name with the at least one local name, and if there is a match with any one of the at least one local name, to reply with a response message specifying the local address.

5. A network element according to claim 1 wherein at least one flat name space is a TL1 (transaction language 1) name space.

6. A network element according to claim 1 wherein the address space is an IP (Internet Protocol) address space.

7. A network element according to claim 6 wherein the group of network addresses is a multicast group of IP addresses.

8. A network element according to claim 1 further comprising:

an interface for receiving a command from an external source, the command specifying the requested name.

9. A network element according to claim 1 further comprising:

a second memory element adapted to store a local address;

a procedure by which the network element joins the group of network addresses;

a request message processing element adapted to process a received request message containing a requested name for which a corresponding address is required by comparing the requested name with the at least one local name, and if there is a match with any one of the at least one local name, to reply with a response message specifying the local address.

45. A network comprising a plurality of network elements of claim 1.

10. A network element adapted to perform address resolution from a TL1 address space to an IP address space, the network element comprising:

a first memory element adapted to store a local TL1 SID (system identifier) of the network element;

a second memory element adapted to store previously resolved TL1 TID (target identifier)-to-IP address mappings;

a TL1 message processing element adapted to process a requested TL1 TID by determining if the requested TL1 TID is the local TL1 SID, or a TL1 TID of a previously resolved TL1 TID-to-IP address mapping, and if not to send a request message IP packet to a multicast address of a multicast group containing IP addresses of all network elements which have joined the multicast group, the request message containing the requested TL1 TID for which a corresponding IP address is required.

11. A network element according to claim 10 further adapted to receive a response message specifying a particular IP address for the requested TL1 TID, and to add a TL1 TID-to-IP address mapping to the second memory element identifying the particular IP address as being the network address for the requested TL1 TID.

12. A network element according to claim 11 further comprising:

a procedure run to define the multicast group if not already in existence.

13. A network element according to claim 10 further comprising:

an interface for receiving a TL1 command from an external source, the TL1 command specifying the requested TL1 TID.

14. A network element according to claim 10 adapted to be connected to a network in an add/drop configuration so as to perform an add/drop multiplexing function on physical layer frames being transmitted on the network.

15. A network element according to claim 10 adapted to have a stack interface between IP packets and physical layer frames.

16. A network element according to claim 15 wherein the stack interface is adapted to insert the IP packets in a channel defined by predetermined byte locations in the physical layer frames.

17. A network element according to claim 15 wherein the physical layer frames are SONET frames.

18. A network element according to claim 15 wherein the physical layer frames are SONET frames and the predetermined byte locations are SONET D1 to D12 overhead bytes.

19. A network element according to claim 10 which is a SONET network element.

20. A network element according to claim 10 further comprising:

an IP stack with a local IP address;

a procedure by which the network element joins the multicast group having the multicast address;

a TID request message processing element adapted to process a received request message received through the multicast address containing a requested TL1 TID for which a corresponding IP address is required by comparing the requested TL1 TID with the local TL1 SID, and if there is a match, to reply with a response message sent by IP unicast specifying the local IP address.

46. A network comprising a plurality of network elements of claim 11.

21. A network element adapted to perform address resolution from a flat name space to a network address space, the network element comprising:

a stack with a local network address belonging to the address space;

a memory element adapted to store a local name of the network element, the local name belonging to the flat name space;

a procedure by which the network element joins a group of addresses;

a request message processing element adapted to process a request message sent to the group of network addresses containing a requested name for which a corresponding address is required by comparing the requested name with the local name, and if there is a match, to reply with a response message specifying the local network address.

22. A network element according to claim 21 wherein the name space is a TL1 (Transaction Language 1) name space.

23. A network element according to claim 21 wherein the address space is an IP address space.

24. A network element according to claim 21 wherein the group of network addresses is a multicast group of IP addresses.

25. A network comprising:

a plurality of network elements according to claim 21 connected together, the network being adapted to provide a channel for control packet transmission between network elements of the network on the basis of the respective local addresses;

an interface for receiving a command addressed to a target name;

a name resolution protocol function adapted to determine a network address corresponding with the target name by sending a request message to all network elements in the network asking each network element if their local name matches the target name, and by receiving a response message from the network element whose name matches the target name specifying the address corresponding with the target name.

26. A network according to claim 25:

wherein the network is a SONET ring, with each network element performing an add/drop multiplexing function on SONET frames on the ring.

27. A network according to claim 25 wherein each name is a TL1 TID.

28. A network according to claim 25 wherein each address is an IP address and the request message is sent by IP multicast.

29. A network according to claim 25 wherein the channel for packet transmission comprises overhead bytes in SONET frames.

30. A network element adapted to perform address resolution from a TL1 TID to an IP address, the network element comprising:

an IP stack with a local IP address;

a memory element adapted to store a local TL1 SID of the network element;

a procedure by which the network element joins a multicast group having a multicast address;

a TID request message processing element adapted to process a request message received through the multicast address containing a requested TL1 TID for which a corresponding IP address is required by comparing the requested TL1 TID with the local TL1 SID, and if there is a match, to reply with a response message sent by IP unicast specifying the local IP address.

31. A network element according to claim 30 further comprising:

a procedure run to define the multicast group if not already in existence.

32. A network element according to claim 30 adapted to be connected to a network in an add/drop configuration so as to perform an add/drop multiplexing function on physical layer frames being transmitted on the network.

33. A network element according to claim 32 adapted to have a stack interface between IP packets and physical layer frames.

34. A network element according to claim 33 wherein the stack interface is adapted to insert the DP packets in a channel defined by predetermined byte locations in the physical layer frames.

35. A network element according to claim 33 wherein the physical layer frames are SONET frames.

36. A network element according to claim 34 wherein the physical layer frames are SONET frames and the predetermined byte locations are SONET D1 to D12 overhead bytes.

37. A network element according to claim 30 which is a SONET network element.

38. A method for performing address resolution from a flat name space to an address space, the method comprising:

storing a local name belonging to said flat name space;

maintaining a plurality of previously resolved name-to-address mappings;

processing a requested name belonging to the flat name space by determining if the requested name is the local name or a name of a previously resolved name-to-address mapping, and if not to sending a request message to a group of network addresses in said address space belonging to network elements which have joined the group, the request message containing the requested name for which a corresponding address is required;

receiving a response specifying a particular network address for the requested name, and to adding a name-to-address mapping to the plurality of name-to-address mappings identifying the particular network address as being the network address for the requested name.

39. A method according to claim 38 wherein the flat name space is a TL1 (transaction language 1) name space.

40. A method according to claim 38 wherein the address space is an IP (Internet Protocol) address space.

41. A method according to claim 38 wherein the group of network addresses is a multicast group of IP addresses.

42. A method of responding to a request message generated according to claim 38 comprising:

maintaining another local name and a local address;

comparing the requested name with the another local name, and if there is a match, replying with a response message specifing the local address.

43. A computer readable medium containing computer implementable instructions which implement the method of claim 38.

44. A computer readable medium containing computer implementable instructions which implement the method of claim 42.