Bridging between a bluetooth scatternet and an ethernet LAN

• US 20040141511A1
• Filed: 12/12/2003
• Published: 07/22/2004
• Est. Priority Date: 12/23/2002
• Status: Abandoned Application

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Larsson, Tony, Rune, Johan, Kauppinen, Tero
• Application Number:
  US10/735,047
• Publication Number:
  US 20040141511A1
• Time in Patent Office: Days
• US Class Current: 370/401
• CPC Class Codes: H04L 45/20 Hop count for routing purposes, e.g. TTL
• CPC Class Codes: H04W 40/00 Communication routing or communication path finding
• CPC Class Codes: H04W 84/04 Large scale networks; Deep hierarchical networks
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: H04W 92/02 Inter-networking arrangements

Abstract

System and method are disclosed for bridging a point-to-point network such as a Bluetooth scatternet with a shared medium network such as an Ethernet LAN. The scatternet is connected to the LAN via a network access point (NAP). Data packets sent from the LAN to the scatternet are filtered at the NAP to eliminate unnecessary data packets from being sent to the scatternet. Only certain ones of the data packets are forwarded between the LAN and the scatternet. An inter-NAP protocol is used to exchange messages where two or more NAPs are connected to the LAN. Broadcast loops are prevented from occurring in the scatternet and the LAN by defining Administrative domains and NAP service areas (NAPSAs), and controlling the borders thereof according to a broadcast type of the data packets.

Claims

1. A method of bridging a point-to-point network with a shared medium network, said point-to-point network having a plurality of nodes including at least one network access point, comprising:

connecting said point-to-point network to said shared medium network via said network access point;

receiving data packets from said shared medium network and said point-to-point network;

converting said data packets from a shared medium network format to a point-to-point network format, or vice versa; and

forwarding certain ones of said data packets, including ARP requests and ARP route requests, between said shared medium network and said point-to-point network.

2. The method according to claim 1, wherein said step of forwarding includes receiving said ARP request from a source node in said shared medium network at said network access point, converting said ARP request to said ARP route request in said network access point, sending said ARP route request to said point-to-point network, and indicating said shared medium network as a next hop node in a route entry for a source node of said ARP request.

3. The method according to claim 2, wherein said step of forwarding further includes receiving an ARP route reply from a destination node in said point-to-point network at said network access point in response to said ARP route request, converting said ARP route reply to an ARP reply in said network access point, and sending said ARP reply to said shared medium network.

4. The method according to claim 2, wherein said step of forwarding further includes receiving a broadcast ARP reply from a destination node in said point-to-point network at said network access point in response to said ARP route request, sending said broadcast ARP reply to said shared medium network as a broadcast ARP reply, receiving a unicast ARP route reply from said point-to-point network at said network access point in response to said ARP route request, converting said unicast ARP route reply to a unicast ARP reply in said network access point, and sending said unicast ARP reply to said shared medium network.

5. The method according to claim 1, wherein said step of forwarding includes receiving a unicast data packet from a node in said shared medium network at said network access point without a preceding ARP request, and sending said unicast packet to a destination node in said point-to-point network if a route entry exists for said destination node in said network access point.

6. The method according to claim 5, wherein said step of forwarding further includes broadcasting a non-ARP route request to said point-to-point network from said network access point to establish a route to said destination node if no route entry for said destination node exists in said network access point, and sending said unicast data packet along said established route, wherein a non-ARP route reply received by said network access point in response to said non-ARP route request is not sent to said shared medium network.

7. The method according to claim 1, wherein said step of forwarding includes receiving an ARP route request from a source node in said point-to-point network at said network access point, encapsulating said ARP route request, and sending said encapsulated ARP route request to said shared medium network.

8. The method according to claim 7, wherein said step of forwarding further includes converting said ARP route request into an ARP request, and sending said ARP request to said shared medium network after said encapsulated ARP route request has been sent.

9. The method according to claim 8, wherein no ARP request is sent to said shared medium network if it is determined that a destination node of said ARP request is located in any point-to-point network, and no encapsulated ARP route request is sent to said shared medium network if it is determined that said destination node is located in said shared medium network.

10. The method according to claim 8, wherein said step of forwarding further includes storing a target IP address and source MAC address for said ARP request in said network access point, receiving an ARP reply at said network access point, converting said ARP reply to an ARP route reply, and sending said ARP route reply to said point-to-point network if a sender IP address and target MAC address for said ARP reply matches said stored target IP address and source MAC address of said ARP request.

11. The method according to claim 10, wherein said target IP address and source MAC address for said ARP request are stored in said network access point in a table for pending ARP requests triggered by route requests received from said point-to-point network.

12. The method according to claim 11, wherein said network access point is a first network access point, said step of forwarding further includes receiving said encapsulated ARP route request at a second network access point, storing a target IP address and source MAC address for said encapsulated ARP route request in said second network access point, extracting said ARP route request from said encapsulated ARP route request, sending said ARP route request to said point-to-point network, and indicating another NAP as a next hop node in a route entry for said source node in said second network access point.

13. The method according to claim 12, wherein said target IP address and source MAC address of said encapsulated ARP route request are stored in a table for pending ARP route requests triggered by encapsulated ARP route requests.

14. The method according to claim 12, wherein said step of forwarding further includes receiving said ARP request at said second network access point, comparing a target IP address and source MAC address of said ARP request with said stored target IP address and source MAC address of said encapsulated ARP route request, and if they do not match, converting said ARP request to an ARP route request and sending said converted ARP route request to said point-to-point network.

15. The method according to claim 14, wherein said step of forwarding further includes receiving an ARP route reply from said point-to-point network at said second network access point, encapsulating said ARP route reply, and sending said encapsulated ARP route reply to said shared medium network.

16. The method according to claim 15, wherein said step of forwarding further includes receiving said encapsulated ARP route reply at said first network access point, extracting said ARP route reply from said encapsulated ARP route reply, determining whether a sender IP address and a target MAC address of said ARP route reply matches said stored target IP address and source MAC address of said ARP route request, and sending said ARP route reply to said point-to-point network if a match is found.

17. The method according to claim 14, wherein said step of forwarding further includes receiving an ARP reply from said point-to-point network at said second network access point in response to said ARP route request and sending said ARP reply to said shared medium network.

18. The method according to claim 17, wherein said step of forwarding further includes receiving said ARP reply at said first network access point, determining whether a sender IP address and a target MAC address of said ARP reply matches said stored target IP address and source MAC address of said ARP route request, sending said ARP reply to said point-to-point network if no match is found, and converting said ARP reply to an ARP route reply and sending said ARP route reply to said point-to-point network if a match is found.

19. The method according to claim 18, wherein said ARP reply received from said point-to-point network at said second network access point is a broadcast ARP reply, said step of forwarding further including sending said ARP reply as a broadcast ARP reply from said first network access point to said point-to-point network in addition to said ARP route reply if a match is found.

20. The method according to claim 1, wherein said step of forwarding includes receiving a non-ARP route request from a source node in said point-to-point network at said network access point, encapsulating said non-ARP route request, and sending said encapsulated non-ARP route request to said shared medium network.

21. The method according to claim 20, wherein said step of forwarding further includes sending an unconfirmed proxy non-ARP route reply from said network access point to said point-to-point network, generating an unconfirmed route entry for a destination node of said non-ARP route request in said network access point, and indicating said shared medium network as a next hop node in said unconfirmed route entry.

22. The method according to claim 21, wherein no unconfirmed proxy non-ARP route reply is sent to said point-to-point network if it is determined that said destination node of said non-ARP route request is located in any point-to-point network, and no encapsulated non-ARP route request is sent to said shared medium network if it is determined that said destination node is located in said shared medium network.

23. The method according to claim 21, wherein said network access point is a first network access point, said step of forwarding further includes receiving said encapsulated non-ARP route request at a second network access point, extracting said non-ARP route request from said encapsulated non-ARP route request, and sending said non-ARP route request to said point-to-point network.

24. The method according to claim 22, wherein said step of forwarding further includes receiving a non-ARP route reply from said point-to-point network at said second network access point, encapsulating said non-ARP route reply, and sending said encapsulated non-ARP route reply to said shared medium network.

25. The method according to claim 24, wherein said step of forwarding further includes receiving said encapsulated non-ARP route reply at said first network access point, replacing said unconfirmed route entry with a confirmed route entry for said destination node, extracting said non-ARP route reply from said encapsulated non-ARP route reply, and sending said non-ARP route reply to said point-to-point network.

26. The method according to claim 1, wherein said step of forwarding includes receiving an ARP route request from a source node in said point-to-point network at said network access point, creating a route entry for said source node if no previous route entry for said source node exists, converting said ARP route request into an ARP request, and sending said ARP request to said shared medium network.

27. The method according to claim 26, wherein said step of forwarding further includes storing, in said network access point, a target IP address and source MAC address for said ARP request, a pointer to said route entry for said source node, and a type of reply indicator.

28. The method according to claim 27, wherein said target IP address and source MAC address for said ARP request, said pointer to said route entry for said source node, and said type of reply indicator are stored in said network access point in a table for pending ARP requests triggered by route requests received from said point-to-point network.

29. The method according to claim 28, wherein said type of reply indicator indicates an ARP route reply, and said pointer to said route entry is a source MAC address of said ARP route request.

30. The method according to claim 29, wherein said network access point is a first network access point, said step of forwarding further includes receiving said ARP request at a second network access point connected to said shared medium network, converting said ARP request to an ARIP route request and sending said ARP route request from said second network access point to said point-to-point network.

31. The method according to claim 30, wherein said step of forwarding further includes receiving an ARP route reply from said point-to-point network at said second network access point in response to said ARP route request, converting said ARP route reply to an ARP reply, and sending said ARP reply to said shared medium network.

32. The method according to claim 31, wherein said step of forwarding further includes receiving a broadcast ARP reply from said point-to-point network at said second network access point in response to said ARP route request and sending said broadcast ARP reply to said shared medium network.

33. The method according to claim 30, wherein said step of forwarding further includes receiving an ARP reply at said first network access point, determining whether a sender IP address and target MAC address of said ARP reply matches said stored target IP address and source MAC address, and if a match is found, converting said ARP reply to an ARP route reply if the type of reply indicator indicates an ARP route reply and sending said ARP route reply to said point-to-point network.

34. The method according to claim 33, wherein said step of forwarding further includes removing said matching entry from said table for pending ARP requests triggered by route requests received from said point-to-point network.

35. The method according to claim 1, wherein said step of forwarding includes receiving a non-ARP route request from a source node in said point-to-point network at said network access point, retrieving a destination node 1P address for said non-ARP route request from an ARP cache, generating a new ARP request using said retrieved IP address as a target IP address and a MAC address of said network access point as a sender MAC address for said new ARP request, using an IP address of said network access point as a sender IP address and said MAC address of said network access point as a source MAC address for said new ARP request, and sending said new ARP request to said shared medium network.

36. The method according to claim 35, wherein said step of forwarding further includes storing, in said network access point, said target IP address and source MAC address for said new ARP request, a pointer to said route entry for said source node, and a type of reply indicator.

37. The method according to claim 36, wherein said target IP address and source MAC address for said new ARP request, said pointer to said route entry for said source node, and said type of reply indicator are stored in said network access point in a table for pending ARP requests triggered by route requests received from said point-to-point network.

38. The method according to claim 37, wherein said type of reply indicator indicates a non-ARP route reply, and said pointer to said route entry is a source MAC address of said non-ARP route request.

39. The method according to claim 27, wherein said step of forwarding further includes receiving a unicast ARP reply at said network access point, comparing a sender IP address and target MAC address of said unicast ARP reply with said stored target IP address and source MAC address, and if a match is found, converting said unicast ARP reply to a non-ARP route reply if said type of reply indicator indicates a non-ARP route reply, and sending said non-ARP route reply to said point-to-point network.

40. The method according to claim 35, wherein if said destination node IP address cannot be received from said ARP cache, said step of forwarding further includes sending an unconfirmed proxy non-ARP route reply from said network access point to said point-to-point network, generating an unconfirmed route entry for a destination node of said non-ARP route request in said network access point, and indicating said shared medium network as a next hop node in said unconfirmed route entry.

41. A system for bridging a point-to-point network with a shared medium network, comprising:

a plurality of nodes in said point-to-point network and said shared medium network, said nodes including at least one network access point connecting said point-to-point network to said shared medium network;

a bridging function in said network access point configured to convert said data packets from a shared medium network format to a point-to-point network format, or vice versa, and forward certain ones of said data packets, including ARP requests and ARP route requests, between said shared medium network and said point-to-point network.

42. The system according to claim 41, wherein said network access point receives an ARP request from a source node in said shared medium network, said bridging function configured to cause said network access point to convert said ARP request to an ARP route request, send said ARP route request to said point-to-point network, and indicate said shared medium network as a next hop node in a route entry for a source node of said ARP request in said network access point.

43. The system according to claim 42, wherein said network access point receives an ARP route reply from a destination node in said point-to-point network in response to said ARP route request, said bridging function further configured to cause said network access point to convert said ARP route reply to an ARP reply and send said ARP reply to said shared medium network.

44. The system according to claim 42, wherein said network access point receives a broadcast ARP reply from a destination node in said point-to-point network in response to said ARP route request, said bridging function further configured to cause said network access point to send said broadcast ARP reply to said shared medium network as a broadcast ARP reply, and when a unicast ARP route reply from said point-to-point network is received at said network access point in response to said ARP route request, said bridging function further configured to cause said network access point to convert said ARP route reply to an ARP reply and send said ARP reply to said shared medium network.

45. The system according to claim 41, wherein said network access point receives a unicast data packet from a node in said shared medium network without a preceding ARP request, said bridging function further configured to cause said network access point to send said unicast packet to a destination node in said point-to-point network if a route entry exists for said destination node in said network access point.

46. The system according to claim 45, wherein said bridging function is further configured to cause said network access point to broadcast a non-ARP route request to said point-to-point network to establish a route to said destination node if no route entry for said destination node exists in said network access point, and send said unicast data packet along said established route, wherein a non-ARP route reply received by said bridging function in response to said non-ARP route request is not sent to said shared medium network.

47. The system according to claim 41, wherein said network access point receives an ARP route request from a source node in said point-to-point network, said bridging function further configured to cause said network access point to send said ARP route request as an encapsulated ARP route request to said shared medium network.

48. The system according to claim 47, wherein said bridging function is further configured to cause said network access point to convert said ARP route request into an ARP request and send said ARP request to said shared medium network after said encapsulated ARP route request has been sent.

49. The system according to claim 48, wherein no ARP request is sent to said shared medium network from said bridging function if it is determined that a destination node of said ARP request is located in any point-to-point network, and no encapsulated ARP route request is sent to said shared medium network from said bridging function if it is determined that said destination node is located in said shared medium network.

50. The system according to claim 48, wherein said bridging function is further configured to cause said network access point to store a target IP address and source MAC address for said ARP request in said network access point, and when an ARP reply is received at said network access point, said bridging function is further configured to cause said network access point to convert said ARP reply to an ARP route reply and send said ARP route reply to said point-to-point network if a sender IP address and target MAC address for said ARP reply matches said stored target IP address and source MAC address of said ARP request.

51. The system according to claim 50, wherein said target IP address and source MAC address for said ARP request are stored in said network access point in a table for pending ARP requests triggered by route requests received from said point-to-point network.

52. The system according to claim 51, wherein said network access point is a first network access point and said encapsulated ARP route request is received at a second network access point, said second network access point having a bridging function that is configured to cause said second network access point to store a target IP address and source MAC address for said encapsulated ARP route request, send an ARP route request contained in said encapsulated ARP route request to said point-to-point network, and indicate another NAP as a next hop node in a route entry for said source node in said second network access point.

53. The system according to claim 52, wherein said target IP address and source MAC address of said encapsulated ARP route request are stored in a table for pending ARP route requests triggered by encapsulated ARP route requests.

54. The system according to claim 52, wherein said ARP request sent by said first network access point is received at said second network access point, said bridging function of said second network access point further configured to cause said second network access point to compare a target IP address and source MAC address of said ARP request with said stored target IP address and source MAC address of said encapsulated ARP route request, and if they do not match, convert said ARP request to an ARP route request and send said converted ARP route request to said point-to-point network.

55. The system according to claim 52, wherein an ARP route reply from said point-to-point network is received at said second network access point, said bridging function of said second network access point further configured to cause said second network access point to send said ARP route reply as an encapsulated ARP route reply to said shared medium network.

56. The system according to claim 55, wherein said encapsulated ARP route reply is received at said first network access point, said bridging function of said first network access point further configured to cause said first network access point to determine whether a sender IP address and a target MAC address of said encapsulated ARP route reply matches said stored target IP address and source MAC address of said ARP route request, and send said ARP route reply contained in said encapsulated ARP route reply to said point-to-point network if a match is found.

57. The system according to claim 54, wherein an ARP reply from said point-to-point network is received at said second network access point in response to said ARP route request, said bridging function of said second network access point further configured to cause said second network access point to send said ARP reply to said shared medium network.

58. The system according to claim 57, wherein said ARP reply is received at said first network access point, said bridging function of said first network access point further configured to cause said first network access point to determine whether a sender IP address and a target MAC address of said ARP reply matches said stored target IP address and source MAC address of said ARP route request, send said ARP reply to said point-to-point network if no match is found, and convert said ARP reply to an ARP route reply and send said ARP route reply to said point-to-point network if a match is found.

59. The system according to claim 58, wherein said ARP reply received from said point-to-point network at said second network access point is a broadcast ARP reply, said bridging function of said first network access point further configured to cause said first network access point to send said ARP reply as a broadcast ARP reply from said to said point-to-point network in addition to said ARP route reply if a match is found.

60. The system according to claim 41, wherein a non-ARP route request is received at said network access point from a source node in said point-to-point network, said bridging function further configured to cause said network access point to encapsulate said non-ARP route request and send said encapsulated non-ARP route request to said shared medium network.

61. The system according to claim 60, wherein said bridging function further configured to cause said network access point to send an unconfirmed proxy non-ARP route reply to said point-to-point network, generate an unconfirmed route entry for said destination node of said non-ARP route request, and indicate said shared medium network as a next hop node in said unconfirmed route entry.

62. The system according to claim 61, wherein no unconfirmed proxy non-ARP route reply is sent to said point-to-point network if it is determined that said destination node of said non-ARP route request is located in any point-to-point network, and no encapsulated non-ARP route request is sent to said shared medium network if it is determined that said destination node is located in said shared medium network.

63. The system according to claim 61, wherein said network access point is a first network access point and said encapsulated non-ARP route request is received at a second network access point, said second network access point having a bridging function that is configured to cause said second network access point to extract said non-ARP route request from said encapsulated non-ARP route request, and send said non-ARP route request to said point-to-point network.

64. The system according to claim 62, wherein a non-ARP route reply from said point-to-point network at said second network access point, said bridging function of said second network access point further configured to cause said second network access point to encapsulate said non-ARP route reply and send said encapsulated non-ARP route reply to said shared medium network.

65. The system according to claim 64, wherein said encapsulated non-ARP route reply is received at said first network access point, said bridging function of said first network access point further configured to cause said first network access point to replace said unconfirmed route entry with a confirmed route entry for said destination node, extract said non-ARP route reply from said encapsulated non-ARP route reply, and send said non-ARP route reply to said point-to-point network.

66. The system according to claim 41, wherein an ARP route request from a source node in said point-to-point network is received at said network access point, said bridging function configured to cause said network access point to create a route entry for said source node if no previous route entry for said source node exists, convert said ARP route request into an ARP request, and send said ARP request to said shared medium network.

67. The system according to claim 66, wherein said bridging function is further configured to cause said network access point to store a target IP address and source MAC address for said ARP request, a pointer to said route entry for said source node, and a type of reply indicator.

68. The system according to claim 67, wherein said target IP address and source MAC address for said ARP request, said pointer to said route entry for said source node, and said type of reply indicator are stored in said network access point in a table for pending ARP requests triggered by route requests received from said point-to-point network.

69. The method according to claim 68, wherein said type of reply indicator indicates an ARP route reply, and said pointer to said route entry is a source MAC address of said ARP route request.

70. The system according to claim 69, wherein said network access point is a first network access point and an ARP request is received at a second network access point connected to said shared medium network, said second network access point having a bridging function therein configured to cause said second network access point to convert said ARP request to an ARP route request and send said ARP route request from said second network access point to said point-to-point network.

71. The system according to claim 70, wherein an ARP route reply from said point-to-point network is received at said second network access point in response to said ARP route request, said bridging function of said second network access point further configured to cause said second network access point to convert said ARP route reply to an ARP reply, and send said ARP reply to said shared medium network.

72. The system according to claim 71, wherein a broadcast ARP reply from said point-to-point network is received at said second network access point in response to said ARP route request, said bridging function of said second network access point further configured to cause said second network access point to send said broadcast ARP reply to said shared medium network.

73. The system according to claim 70, wherein an ARP reply is received at said first network access point, said bridging function of said first network access point further configured to cause said first network access point to determine whether a sender IP address and target MAC address of said ARP reply matches said stored target IP address and source MAC address, and if a match is found, convert said ARP reply to an ARP route reply if the type of reply indicator indicates an ARP route reply and send said ARP route reply to said point-to-point network.

74. The system according to claim 73, wherein said bridging function of said first network access point is further configured to cause said first network access point to remove said matched entry from said table for pending ARP requests triggered by route requests received from said point-to-point network.

75. The system according to claim 41, wherein a non-ARP route request from a source node in said point-to-point network is received at said network access point, said bridging function further configured to cause said network access point to retrieve a destination node IP address for said non-ARP route request from an ARP cache, generate a new ARP request us said retrieved IP address as a target IP address and a MAC address of said network access point as a sender MAC address for said new ARP request, use an IP address of said network access point as a sender IP address and said MAC address of said network access point as a source MAC address for said new ARP request, and send said new ARP request to said shared medium network.

76. The system according to claim 75, wherein said bridging function further configured to cause said network access point to store said target IP address and source MAC address for said new ARP request, a pointer to said route entry for said source node, and a type of reply indicator.

77. The system according to claim 76, wherein said target IP address and source MAC address for said new ARP request, said pointer to said route entry for said source node, and said type of reply indicator are stored in said network access point in a table for pending ARP requests triggered by route requests received from said point-to-point network.

78. The system according to claim 77, wherein said type of reply indicator indicates a non-ARP route reply, and said pointer to said route entry is a source MAC address of said non-ARP route request.

79. The system according to claim 67, wherein a unicast ARP reply is received at said network access point, said bridging function further configured to cause said network access point to compare a sender IP address and target MAC address of said unicast ARP reply with said stored target IP address and source MAC address, and if a match is found, convert said unicast ARP reply to a non-ARP route reply if said type of reply indicator indicates a non-ARP route reply, and send said non-ARP route reply to said point-to-point network.

80. The system according to claim 75, wherein if said destination node IP address cannot be retrieved from said ARP cache, said bridging function further configured to cause said network access point to send an unconfirmed proxy non-ARP route reply from said network access point to said point-to-point network, generate an unconfirmed route entry for a destination node of said non-ARP route request in said network access point, and indicate said shared medium network as a next hop node in said unconfirmed route entry.