LAN TOPOLOGY DETECTION AND ASSIGNMENT OF ADDRESSES

• US 20070291665A1
• Filed: 02/26/2007
• Published: 12/20/2007
• Est. Priority Date: 06/14/2006
• Status: Active Grant

• Current Assignee: RPX Corporation
• Original Assignee: Nokia Corporation
• Inventors: Niggemeier, Peter, Hauenstein, Markus
• Granted Patent: US 8,331,266 B2
• Time in Patent Office: Days
• US Class Current: 370/255
• CPC Class Codes: H04L 12/4645 Details on frame tagging routing of packets H04L45/00; support for virtual LAN H04L49/354
• CPC Class Codes: H04L 12/467 Arrangements for supporting untagged frames, e.g. port-based VLANs
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• CPC Class Codes: H04L 43/045 for graphical visualisation of monitoring data
• CPC Class Codes: H04L 61/5038 for local use, e.g. in LAN or USB networks, or in a controller area network [CAN]

Abstract

A method, system, device and computer program product for automatically detecting a topology of a local area network, LAN. The LAN may be included in a telecommunication node, e.g. a base transceiver station. The LAN includes a central host and further hosts connected to the LAN. The central host sends topology descriptors to the hosts connected to the LAN, the hosts each reporting at least one of the received topology descriptors and other information to the central host. The central host can thus build up a topology data base describing the network topology. The topology descriptors are sent in broadcast frames to the hosts. A host, after having received a topology descriptor, may create one or more dedicated addresses, e.g. from the topology descriptor, and return the address(es) to the central host which may store the address(es).

Claims

1. A method for detecting a network topology of a local area network, the local area network comprising a central host and at least one further host, the method comprising:

sending topology descriptors from the central host to the at least one further host;

receiving a sent topology descriptor at the at least one further host;

each of the at least one further host reporting the received topology descriptor to the central host;

the central host building up a topology data base describing the network topology based on the reported received topology descriptors.

2. The method of claim 1, wherein the topology descriptors are sent via least one of:

broadcast from the central host to the at least one further host;

sent in broadcast frames;

sent in payloads of broadcast frames; and

sent in untagged broadcast frames.

6. The method of claim 1, wherein the at least one further host and the central host are network elements which are interconnected via the local area network.

7. The method of claim 1, wherein the at least one further host and the central host are internal elements of a local area network based network element.

8. The method of claim 7, wherein at least one of the internal elements is a switch, and connections between the internal elements are of point-to-point type connections.

9. The method of claim 1, wherein the topology descriptors are sent in frames, and wherein the method further comprises filtering the sent frames containing the topology descriptors.

11. The method of claim 9, wherein the filtering is based on tags in the frames received from the central host.

12. The method of claim 11, wherein the tags are removed from filtered frames that are dedicated to a potential host connected to a certain port.

13. The method of claim 11, wherein:

received non-tagged frames are broadcasted to all ports of the at least one switch;

a plurality of filtering hierarchies are used to enlarge the local area network and to increase the number of hosts that can be connected;

tagged frames targeted to a host on a lower hierarchy level are forwarded to ports of the switch without removing the tag;

a switch on a lower level receives tagged frames and filters them based on the tags; and

a switch on a lower level removes a tag from filtered frames that are dedicated to a potential host connected to a certain port of the switch.

15. A method according to claim 1, wherein a host receiving dedicated frame is adapted to check whether a received frame is tagged and to process only non tagged frames, ignoring tagged frames.

16. A method according to claim 1, wherein the at least one host computes at least one unique address based on the received topology descriptor.

17. A method according to claim 1, wherein the at least one further host includes a pre-programmed look-up table used for performing at least one of computing one or more addresses and generating the one or more addresses by appending the received topology descriptors to a prefix.

19. A method according to claim 1, wherein a reporting message of the at least one further host to the central host contains information comprising at least one of:

all topology descriptors received by the at least one further host,

the host type, and

at least one computed address of the at least one further host.

21. A method according to claim 1, wherein the local area network includes at least one intermediate switch provided between the central host and the at least one further host, and wherein the central host detects the existence of the at least one intermediate switch from the reported descriptors.

22. A method according to claim 1, wherein the local area network includes at least one intermediate switch provided between the central host and the at least one further host, the at least one intermediate switch having a fixed uplink port for communication with the central host.

24. A method according to claim 1, wherein port numbers of ports to which the at least one further host is connected are used to generate identifiers for identifying the at least one further host in the local area network.

25. A method according to claim 1, wherein the central host assigns addresses to the at least one further host based on at least one of the topology and the topology descriptors.

26. A method according to claim 1, wherein an intermediate switch is provided in a virtual local area network connected to the at least one further host and the central host, the central host having a switch, and wherein a matrix is used in the switch of a central box including the central host and its transpose matrix is used in the intermediate switch.

27. A method according to claim 1, wherein the local area network comprises at least one of an Ethernet local area network, a virtual local area network, and wherein the at least one further host is an Ethernet host.

43. A computer program product, embodied in a computer-readable medium, comprising computer code for carrying out the processes of claim 1.

44. The method of claim 9, wherein the sent frames containing the topology descriptors are filtered in such a way that only frames dedicated to a certain host reach or are processed by that host.

3. (canceled)

4. (canceled)

5. (canceled)

18. A method according to claim 5, wherein the dedicated frames contain at least one address from which the at least one host selects its host address.

10. (canceled)

14. (canceled)

20. (canceled)

23. (canceled)

28. A system for detecting a topology of a node, comprising:

a local area network having a central host; and

at least one further host connected to the local area network, wherein;

the central host of the local area network is configured to send topology descriptors to the at least one further host connected to the local area network,

the at least one further host is configured to report the received topology descriptor and/or other information to the central host, and

the central host of the local area network is configured to build up a topology data base describing the network topology based on the reported information.

29. The system according to claim 28, wherein the at least one further host is configured to send a reporting message to the central host, the reporting message containing at least one of:

the received topology descriptor,

all topology descriptors received by the host,

the host type, and

at least one address belonging to the at least one further host.

30. A system according to claim 28, wherein the local area network includes at least one intermediate switch provided between the central host and the at least one further host, the at least one intermediate switch having a fixed uplink port for communication with the central host.

31. A system according to claim 28, wherein the system is configured to assign at least one address to the at least one further host, wherein the at least one further host, after having received a topology descriptor, is configured to create the at least one address, and return the at least one created address to the central host, and wherein the central host stores the at least one created address.

32. A system according to claim 28, wherein the system is configured to assign at least one address to at least one further host, wherein the central host is adapted to create the at least one address for the at least one further host and to assign the at least one created address to the at least one further host.

33. A system according to claim 28, wherein the node is selected from one of a communication node;

a telecommunication node and a base transceiver station.

34. A host in a local area network, configured to:

send, when receiving one or more topology descriptors from a central host of the local area network, a reporting message to the central host, the reporting message containing at least one of;

the received topology descriptor,

all topology descriptors received by the host,

the host type, and

at least one computed address belonging to the host.

35. A host according to claim 34, wherein the host is adapted to ignore tagged frames and to evaluate only untagged frames.

36. A host according to claim 35, wherein the host is configured to create at least one address and to return the at least one created address to the central host.

37. A host according to claim 36, wherein the at least one address created by the host comprise at least one of a Media Access Control address and an Internet Protocol address.

38. A host according to claim 36, wherein the host is configured to create the at least one address by using a look-up operation for looking up in a pre-defined table mapping topology descriptors to addresses.

39. A host according to claim 36, wherein the host is configured to create an identifier for identifying the host in the local area network based on a port number of a port to which the host is connected.

40. A central host in a local area network, configured to:

send topology descriptors to other hosts connected to the local area network, and to receive, from each of the other hosts, at least one of;

the host type of the respective other host,

the topology descriptor received by the respective other host,

all topology descriptors received by the respective other host, and

at least one address belonging to each respective other host,

and wherein the central host is configured to build up a topology data base describing the network topology based on the received information.

41. A central host according to claim 40, wherein the central host is further configured to send the topology descriptors in one of broadcast frames and payloads of broadcast frames.

42. A central host according to claim 40, wherein the central host is further configured to provide at least one address to the hosts.