Method for allowing a client to access a wireless system

• US 7,016,328 B2
• Filed: 06/24/2003
• Issued: 03/21/2006
• Est. Priority Date: 06/24/2003
• Status: Expired due to Term

• Current Assignee: Hitachi Energy Switzerland AG (Hitachi, Ltd.)
• Original Assignee: Tropos Networks Incorporated (ABB Limited)
• Inventors: Srikrishna, Devabhaktuni, Chari, Amalavoyal
• Primary Examiner(s): Nguyen, Chau
• Assistant Examiner(s): Moore, Ian N.
• Application Number:
  US10/602,179
• Publication Number:
  US 20040264435A1
• Time in Patent Office: 1,001 Days
• Field of Search: 370/389, 370/310, 3703101-3102, 370/312, 370/351, 370/314, 370/352, 370/328, 370/329, 370/331, 370/332, 370/336, 370/338, 370/345, 370/345.52, 370/442, 370/355, 370/353, 370/356, 370/326, 370/238, 370/469, 370/395.54, 455/433, 455/436, 455/437, 455/439, 455/442, 455/445, 709/238, 709/229, 709/226, 709/230
• US Class Current: 370/331
• CPC Class Codes: H04L 12/2856 Access arrangements, e.g. Internet access asynchronous transfer mode networks H04L12/5601; broadband local area networks H04L12/2801; optical access or distribution networks H04Q11/0067; access to open networks H04L12/5691; digital subscriber line end-user equipment and bit-level processing of data on a PSTN-based network H04M11/00; home network gateways H04L12/2834; wireless access networks H04W
• CPC Class Codes: H04L 45/04 Interdomain routing, e.g. hierarchical routing
• CPC Class Codes: H04L 61/10 of different types
• CPC Class Codes: H04L 61/5014 using dynamic host configuration protocol [DHCP] or bootstrap protocol [BOOTP]
• CPC Class Codes: H04W 40/02 Communication route or path selection, e.g. power-based or shortest path routing
• CPC Class Codes: H04W 40/246 Connectivity information discovery
• CPC Class Codes: H04W 40/248 Connectivity information update
• CPC Class Codes: H04W 40/32 for defining a routing cluster membership
• CPC Class Codes: H04W 40/36 due to handover
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: H04W 88/16 Gateway arrangements

Abstract

An apparatus and method for allowing a client to access a wireless system is disclosed. The system includes at least a first wireless access node. The method includes the first wireless access node detecting a client seeking access to the system. The first wireless access node being able to wirelessly connect to a back bone network. Client information is obtained. The first wireless node provides the client a communication path to and from a destination. The communication path is able to include wired and wireless communication links. Routing of information through the communication path between the client and the destination is aided based upon detection of the client. The wireless connection between the first access node and the back bone network can include at least one wireless hop between the first access node and a third access node.

Claims

1. A method of allowing a client to access a wireless system, the system comprising at least a first wireless access node, the method comprising:

the first wireless access node detecting the client seeking access to the system, the first wireless access node able to wirelessly connect to a back bone network;

the first wireless access node obtaining client information, the client information comprising an IP address of the client'"'"'s default gateway, and the client'"'"'s IP address, wherein the IP address of the client'"'"'s default gateway is obtained by the first wireless access node by intercepting and inspecting a DHCP acknowledgement packet, and wherein the client'"'"'s IP address is also obtained by the first wireless access node by interception and inspection of the DHCP acknowledgment packet;

the first wireless access node providing the client a first communication path to and from a destination, the first communication path able to include wired and wireless communication links; and

aiding in routing of information through the first communication path between the client and the destination based upon detection of the client.

2. The method of allowing a client to access a wireless system of claim 1, wherein the wireless connection between the first wireless access node and the back bone network comprises at least one wireless hop between the first wireless access node and a third access node.

3. The method of allowing a client to access a wireless system of claim 1, further comprising:

the client roaming from the first wireless access node to a second wireless access node;

the second wireless access node detecting the client seeking access to the system, the second wireless access node able to connect to the back bone network;

obtaining client information;

the second wireless access node providing the client a second communication path to and from the destination, the second communication path able to include wired and wireless communication links; and

aiding in routing of information through the second communication path between the client and the destination based upon detection of the client.

4. The method of allowing a client to access a wireless system of claim 3, wherein the wireless connection between the second access node and the back bone network comprises at least one wireless hop between the second access node and a fourth access node.

5. The method of allowing a client to access a wireless system of claim 3, wherein the first wireless access node and the second wireless access node belong to a common cluster.

6. The method of allowing a client to access a wireless system of claim 3, wherein the first wireless access node belong to a first cluster, and the second wireless access node belongs to a second cluster.

7. The method of allowing a client to access a wireless system of claim 6, wherein the first cluster is connected to a first subnet, and the second cluster is connected to a second subnet.

8. The method of allowing a client to access a wireless system of claim 3, wherein the second wireless access node allows the client to maintain a same default gateway IP address as client roams from the first wireless access node.

9. The method of allowing a client to access a wireless system of claim 3, wherein the second wireless access node allows the client to maintain a same default gateway MAC address as client roams from the first wireless access node.

10. The method of allowing a client to access a wireless system of claim 1, wherein a first gateway maintains information pertaining to the client.

11. The method of allowing a client to access a wireless system of claim 10, wherein the first gateway is within a same cluster as the first wireless access node.

12. The method of allowing a client to access a wireless system of claim 1, wherein at least a third gateway not within a same cluster as the first wireless access node maintains information pertaining to the client.

13. The method of allowing a client to access a wireless system of claim 1, wherein at least two gateways maintain client information parameters.

14. The method of allowing a client to access a wireless system of claim 3, wherein at least two gateways maintain client information parameters.

15. The method of allowing a client to access a wireless system of claim 1, wherein a network management system connected to the wireless system maintains information pertaining to the client.

16. The method of allowing a client to access a wireless system of claim 3, wherein a second gateway within a same cluster as the second wireless access node maintains information pertaining to the client.

17. The method of allowing a client to access a wireless system of claim 1, wherein the first wireless access node references at least one of:

a first gateway within a same cluster as the first wireless access node, and a third gateway, to obtain client information regarding the client.

18. The method of allowing a client to access a wireless system of claim 1, wherein the first wireless access node obtains the client information from a gateway by sending an anti-ARP request.

19. The method of allowing a client to access a wireless system of claim 1, wherein if a first requested gateway does not have the client information, then the first requested gateway requests the client information from another gateway.

20. The method of allowing a client to access a wireless system of claim 19, wherein the requests of the first gateway can be transmitted over a back haul interface of the first gateway.

21. The method of allowing a client to access a wireless system of claim 19, wherein the requests of the first gateway can be unicast as IP datagrams.

22. The method of allowing a client to access a wireless system of claim 19, wherein the requests of the first gateway can be multicast to other gateways.

23. The method of allowing a client to access a wireless system of claim 19, wherein the requests of the first gateway can be broadcast to other gateways.

24. The method of allowing a client to access a wireless system of claim 18, wherein the anti-ARP request is continuously re-transmitted until a response is received.

25. The method of allowing a client to access a wireless system of claim 17, wherein if none of the gateways have information regarding the client, then information regarding the client is obtained by the first wireless access node querying a network interface card driver of the access node that is detecting the client.

26. The method of allowing a client to access a wireless system of claim 17, wherein if none of the gateways have information regarding the client, then an IP address of the client is obtained by the first wireless access node by at least one of:

pinging the broadcast address, snooping IP datagrams originating from MAC address of client, the first wireless access node inspecting a DHCP acknowledgment packet.

27. The method of allowing a client to access a wireless system of claim 26, wherein information of a second gateway is updated with the obtained client information.

28. The method of allowing a client to access a wireless system of claim 17, wherein if none of the gateways have information regarding the client, then a default gateway IP address of the client is obtained by interception and inspection by the first wireless access node of a DHCP acknowledgment packet sent to the client.

29. The method of allowing a client to access a wireless system of claim 10, wherein the first gateway can provide a proxy ARP so that a device outside of the wireless system can be spoofed into sending frames addressed to the client IP address to the MAC address of the first gateway.

30. The method of allowing a client to access a wireless system of claim 6, wherein a second gateway gratuitously sends an APP to an edge router upon the client switching from a first cluster to a second cluster so that an ARP cache within the edge router can be updated.

31. The method of allowing a client to access a wireless system of claim 6, wherein an IP-in-IP tunnel is created between a first gateway of the first cluster and a second gateway of the second cluster.

32. The method of allowing a client to access a wireless system of claim 31, wherein the first cluster is connected to a first subnet, and the second cluster is connected to a second subnet, and information destined for the client through the first gateway is rerouted to the second gateway through an IP-in-IP encapsulated tunnel.

33. The method of allowing a client to access a wireless system of claim 31, wherein the first gateway and the second gateway are maintained by a network management system, and the network management system controls creation, maintenance, and removal, of an IP-in-IP tunnel formed between the first gateway and the second gateway.

34. The method of allowing a client to access a wireless system of claim 31, wherein data traffic for the client is received by the first gateway, encapsulated within an IP datagram having a same destination IP address as the second gateway, and routed through the tunnel.

35. The method of allowing a client to access a wireless system of claim 34, wherein the second gateway decapsulates the IP datagram by stripping an IP header, and routes the data traffic based upon an IP destination address.

36. The method of allowing a client to access a wireless system of claim 1, wherein the first IP address remains fixed as the client roams.

37. The method of allowing a client to access a wireless system of claim 36, wherein a default gateway IP address that is consistent with a local subnet is dynamically assigned to the client by the DHCP server.

38. The method of allowing a client to access a wireless system of claim 37, wherein the default route on the client device remains fixed as the client roams.

39. The method of allowing a client to access a wireless system of claim 38, wherein both the first IP address and the default gateway route on the client device remain fixed as the client roams within a cluster, both the first IP address and the default gateway route on the client device remain fixed as the client roams between clusters having a common subnet, both the first IP address and the default gateway route on the client device remain fixed as the client roams between clusters having different subnets.

40. The method of allowing a client to access a wireless system of claim 38, wherein the default gateway route on the client device remain fixed as the client roams within a cluster, the default gateway route on the client device remain fixed as the client roams between clusters having a common subnet, and the default gateway route on the client device remain fixed as the client roams between clusters having different subnets.

41. The method of allowing a client to access a wireless system of claim 1, wherein both the first IP address and the default gateway route on the client device remain fixed as the client roams within a cluster, between clusters having a common subnet, between clusters having different subnets.

42. The method of allowing a client to access a wireless system of claim 1, wherein aiding in a routing of information through the communication path between the client includes updating a routing table for each of the access nodes and gateways that exist in the communication path between the first wireless access node and the destination.

43. The method of allowing a client to access a wireless system of claim 1, wherein routing tables of other network elements on the backbone network may be updated.

44. The method of allowing a client to access a wireless system of claim 10, wherein the client information expires out of the first gateway database unless the client information is periodically refreshed.

50. The method of allowing a client to access a wireless system of claim 38, wherein an ARP cache entry on the client does not change as the client roams.

51. The method of allowing a client to access a wireless system of claim 50, wherein both the first IP address and the default gateway route on the client device remain fixed as the client roams within a cluster, between clusters having a common subnet, between clusters having different subnets.

45. A wireless system, the system comprising at least a first wireless access node, the system further comprising:

means for the first wireless access node detecting a client seeking access to the system, the first wireless access node able to wirelessly connect to a back bone network;

means for the first wireless access node obtaining client information, the client information comprising an IP address of the client'"'"'s default gateway, and the client'"'"'s IP address, wherein the IP address of the client'"'"'s default gateway is obtained by the first wireless access node by intercepting and inspecting a DHCP acknowledgement packet, and wherein the client'"'"'s IP address is also obtained by the first wireless access node by interception and inspection of the DHCP acknowledgment packet;

means for the first wireless access node providing the client a first communication path to and from a destination, the first communication path able to include wired and wireless communication links; and

means for the first wireless access node aiding in routing of information through the first communication path between the client and the destination based upon detection of the client.

46. The wireless system of claim 45, wherein the wireless connection between the first wireless access node and the back bone network comprises at least one wireless hop between the first wireless access node and a third access node.

47. The wireless system of claim 45, further comprising:

means for allowing the client to roam from the first wireless access node to a second wireless access node;

means for the second wireless access node detecting the client seeking access to the system, the second wireless access node able to connect to the back bone network;

means for the second wireless access node for obtaining client information;

means for the second wireless node providing the client a second communication path to and from the destination, the second communication path able to include wired and wireless communication links; and

means for the second wireless access node aiding in a routing of information through the second communication path between the client and the destination based upon detection of the client.

48. The method of allowing a client to access a wireless system of claim 47, wherein the wireless connection between the second wireless access node and the back bone network comprises at least one wireless hop between the second wireless access node and a fourth access node.

49. A first wireless access node, the first wireless access node comprising:

means for detecting a client seeking access to the system, the first wireless access node able to wirelessly connect to a back bone network;

means for obtaining client information, the client information comprising an IP address of the client'"'"'s default gateway and the client'"'"'s IP address, wherein the IP address of the client'"'"'s default gateway is obtained by the first wireless access node by intercepting and inspecting a DHCP acknowledgement packet, and wherein the client'"'"'s IP address is also obtained by the first wireless access node by interception and inspection of the DHCP acknowledgment packet;

the first wireless access node including means for providing the client a first communication path to and from a destination, the first communication path able to include wired and wireless communication links; and

means for aiding in a routing of information through the first communication path between the client and the destination based upon detection of the client.

52. A method of allowing a client to access a wireless system, the system comprising at least a first wireless access node, the method comprising:

the first wireless access node detecting the client seeking access to the system, the first wireless access node able to wirelessly connect to a back bone network;

the first wireless access node obtaining client information, the client information comprising an IP address of the client'"'"'s default gateway, wherein the IP address of the client'"'"'s default gateway is assigned to the client by a DHCP server;

the first wireless access node providing the client a first communication path to and from a destination, the first communication path able to include wired and wireless communication links; and

aiding in routing of information through the first communication path between the client and the destination based upon detection of the client;

wherein the first wireless access node obtains the client information from a gateway by sending an anti-ARP request, if no gateway referenced by the first wireless access node have information regarding the client, then a default gateway IP address of the client is obtained by interception and inspection by the first wireless access node of a DHCP acknowledgment packet sent to the client.

53. The method of allowing a client to access a wireless system of claim 52, wherein a first gateway maintains information pertaining to the client.

54. The method of allowing a client to access a wireless system of claim 53, wherein the first gateway is within a same cluster as the first wireless access node.

55. The method of allowing a client to access a wireless system of claim 53, wherein at least a third gateway not within a same cluster as the first wireless access node maintains information pertaining to the client.

56. The method of allowing a client to access a wireless system of claim 53, wherein at least two gateways maintain client information parameters.

57. The method of allowing a client to access a wireless system of claim 53, wherein a network management system connected to the wireless system maintains information pertaining to the client.

58. The method of allowing a client to access a wireless system of claim 53, wherein the first wireless access node references at least one of:

a first gateway within a same cluster as the first wireless access node, and a third gateway, to obtain client information regarding the client.

59. The method of allowing a client to access a wireless system of claim 53, wherein the first wireless access node obtains the client information from a gateway by sending an anti-ARP request.

60. The method of allowing a client to access a wireless system of claim 53, wherein if a first requested gateway does not have the client information, then the first requested gateway requests the client information from another gateway.

61. The method of allowing a client to access a wireless system of claim 60, wherein the requests of the first gateway can be transmitted over a back haul interface of the first gateway.

62. The method of allowing a client to access a wireless system of claim 60, wherein the requests of the first gateway can be unicast as IP datagrams.

63. The method of allowing a client to access a wireless system of claim 60, wherein the requests of the first gateway can be multicast to other gateways.

64. The method of allowing a client to access a wireless system of claim 60, wherein the requests of the first gateway can be broadcast to other gateways.

65. The method of allowing a client to access a wireless system of claim 59, wherein the anti-ARP request is continuously re-transmitted until a response is received.

66. The method of allowing a client to access a wireless system of claim 59, wherein if none of the gateways have information regarding the client, then information regarding the client is obtained by the first wireless access node querying a network interface card driver of the access node that is detecting the client.

67. The method of allowing a client to access a wireless system of claim 59, wherein if none of the gateways have information regarding the client, then an IP address of the client is obtained by the first wireless access node by at least one of:

pinging the broadcast address, snooping IP datagrams originating from MAC address of client, the first wireless access node inspecting a DHCP acknowledgment packet.

68. The method of allowing a client to access a wireless system of claim 67, wherein information of a second gateway is updated with the obtained client information.

69. The method of allowing a client to access a wireless system of claim 59, wherein if none of the gateways have information regarding the client, then a default gateway IP address of the client is obtained by interception and inspection by the first wireless access node of a DHCP acknowledgment packet sent to the client.

70. A method of allowing a client to access a wireless system, the system comprising at least a first wireless access node, the method comprising:

the first wireless access node detecting the client seeking access to the system, the first wireless access node able to wirelessly connect to a back bone network, wherein detecting the client comprises the first wireless access node detecting a MAC address of the client, the first wireless access node determining an IP address of the client from the MAC address of the client, the first wireless access node determining client information parameters comprising a MAC address of client'"'"'s default gateway, and an IP address of the client;

the first wireless access node obtaining client information, the client information comprising an IP address of the client'"'"'s default gateway, wherein the IP address of the client'"'"'s default gateway is assigned to the client by a DHCP server;

the first wireless access node providing the client a first communication path to and from a destination, the first communication path able to include wired and wireless communication links; and

aiding in routing of information through the first communication path between the client and the destination based upon detection of the client.