Method and system for enabling connections into networks with local address realms

• US 7,533,164 B2
• Filed: 03/28/2003
• Issued: 05/12/2009
• Est. Priority Date: 04/08/2002
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Ismailov, Yuri, Chambert, George, Landfeldt, Bjorn, Korling, Martin, Volz, Bernie
• Primary Examiner(s): Pwu; Jeffrey
• Assistant Examiner(s): Bruckart; Benjamin R
• Application Number:
  US10/510,546
• Publication Number:
  US 20050223095A1
• Time in Patent Office: 2,237 Days
• Field of Search: 709/223, 709/220, 709/226, 709/227, 709/238, 709/230, 709/244, 709/245, 709/250
• US Class Current: 709/223
• CPC Class Codes: H04L 61/2567 for reachability, e.g. inquiring the address of a correspondent behind a NAT server
• CPC Class Codes: H04L 61/2578 without involvement of the NAT server
• CPC Class Codes: H04L 61/2582 through control of the NAT server, e.g. using universal plug and play [UPnP]
• CPC Class Codes: H04L 61/4511 using domain name system [DNS]
• CPC Class Codes: H04L 67/01 Protocols

Abstract

The invention generally concerns the issue of providing connectivity between two different address realms, generally referred to as an inside realm and an outside realm, by establishing connections through an intermediate gateway. The gateway normally has a number of outside-realm gateway addresses for enabling representation of inside-realm nodes in the outside realm. In a first aspect, support for flexible outside-realm initiated connections is enabled by dynamically establishing new gateway connection states triggered, for each new connection, by a respective user-resource identifier query initiated from a corresponding outside node. In a second aspect of the invention, intelligent use of predetermined connection information in the process of setting up new gateway connection states makes it possible to significantly increase the number of connections that can be simultaneously supported by the gateway using a limited number of outside-realm addresses.

Claims

1. A method for supporting establishment of a requested connection between a node of an inside address realm and a node of an outside address realm through an intermediate communication gateway having a gateway address pool comprising a limited number of available outside-realm gateway addresses for enabling outside-realm representation of inside-realm nodes, said method comprising the steps of:

i) providing multiplexing information including at least one of network address information and port information of at least one of said inside-realm node and said outside-realm node;

ii) performing, prior to initiating establishment of said requested connection, a network address allocation procedure to determine an outside-realm gateway address based on a unique combination of one of said limited number of outside-realm gateway addresses and said multiplexing information, said network address allocation procedure including the steps of;

selecting, from said gateway address pool, a candidate outside-realm gateway address for combination with said multiplexing information,

determining whether the combination of the selected candidate outside-realm gateway address and said multiplexing information is already being utilized for another connection;

repeating, if the combination of the selected candidate outside-realm gateway address and said multiplexing information is already being utilized for another connection, the selecting step until a unique combination is found that is not already being utilized for another connection,

wherein the unique combination of outside-realm gateway address and said multiplexing information defines an outside-realm gateway state representation that has no counterpart in a predetermined set of existing gateway connection states, and said determining step is based on a comparison in relation to said predetermined set of existing gateway connection states,

wherein said multiplexing information, for an inside-realm initiated connection, includes at least one of outside node address information and outside node port information, said outside-realm gateway state representation is an at least partially complete gateway state representation, and said predetermined set of gateway connection states includes the existing gateway connection states in said gateway; and

iii) thereafter, initiating establishment of said requested connection based on the unique combination of outside-realm gateway address and said multiplexing information.

2. The method according to claim 1, further comprising the step of maintaining a separate list representation of said predetermined set of existing gateway connection states, and wherein said outside-realm gateway state representation is selected based on comparison with corresponding information of said gateway connection states represented in said list representation.

3. The method according to claim 1, wherein said selecting step also includes selecting associated gateway port information for combination with said multiplexing information, said outside-realm representation is a complete outside-realm representation, and said step of initiating establishment of said connection comprises the step of requesting that said gateway creates a gateway connection state based on said complete outside-realm representation.

4. The method according to claim 1, wherein said outside-realm representation is a partially complete outside-realm representation, and said step of initiating establishment of said connection comprises the step of requesting that said gateway creates a partially complete gateway connection state based on said partially complete outside-realm representation.

5. A method for supporting establishment of a requested connection between a node of an inside address realm and a node of an outside address realm through an intermediate communication gateway having a gateway address pool comprising a limited number of available outside-realm gateway addresses for enabling outside-realm representation of inside-realm nodes, said method comprising the steps of:

i) providing multiplexing information including at least one of network address information and port information of at least one of said inside-realm node and said outside-realm node;

ii) performing, prior to initiating establishment of said requested connection, a network address allocation procedure to determine an outside-realm gateway address based on a unique combination of one of said limited number of outside-realm gateway addresses and said multiplexing information, said network address allocation procedure including the steps of;

selecting, from said gateway address pool, a candidate outside-realm gateway address for combination with said multiplexing information,

determining whether the combination of the selected candidate outside-realm gateway address and said multiplexing information is already being utilized for another connection;

repeating, if the combination of the selected candidate outside-realm gateway address and said multiplexing information is already being utilized for another connection, the selecting step until a unique combination is found that is not already being utilized for another connection,

wherein the unique combination of outside-realm gateway address and said multiplexing information defines an outside-realm gateway state representation that has no counterpart in a predetermined set of existing gateway connection states, and said determining step is based on a comparison in relation to said predetermined set of existing gateway connection states,

wherein said multiplexing information, for an outside-realm initiated connection, includes at least one of outside node address information and inside node port information, said outside-realm gateway state representation is a partially complete gateway state representation and said predetermined set of gateway connection states includes the existing partially complete gateway connection states in said gateway; and

iii) thereafter, initiating establishment of said requested connection based on the unique combination of outside-realm gateway address and said multiplexing information.

6. The method according to claim 5, wherein outside-realm gateway addresses of the gateway are traversed until finding an outside-realm gateway address, which in combination with said multiplexing information has no counterpart in any existing partially complete gateway connection state.

7. The method according to claim 5, wherein said step of determining whether the combination of the selected candidate outside-realm gateway address and said multiplexing information is already being utilized for a connection comprises the step of verifying that a pre-allocated outside-realm gateway address in combination with said

multiplexing information has no counterpart in any existing partially complete gateway connection state.

8. The method according to claim 5, wherein said step of initiating establishment of said connection comprises the step of requesting that said gateway establishes a partially complete gateway connection state based on said partially complete outside-realm representation.

9. The method according to claim 8, further comprising the step of transforming, upon receipt of a packet from said outside node to said gateway, said partially complete gateway connection state that has been created in said gateway into a complete gateway connection state based on complementary connection information associated with said packet.

10. The method according to claim 9, wherein said multiplexing information is predetermined outside node address information, and said complementary connection information includes inside node port information and outside node port information.

11. The method according to claim 9, wherein said multiplexing information is predetermined inside node port information, and said complementary connection information includes outside node address information and outside node port information.

12. The method according to claim 5, further comprising the steps of:

selecting, if it is not possible to find a unique combination based on predetermined inside node port information, another gateway port; and

selecting an outside-realm gateway address based on said selected gateway port to define a unique, partially complete outside-realm representation of a gateway connection state.

13. The method according to claim 5, wherein said multiplexing information originates from a user-resource identifier query initiated from said outside node.

14. The method according to claim 5, wherein said connection establishment is based on said outside-realm gateway state representation and a corresponding inside-realm gateway state representation.

15. The method according to claim 5, further comprising the steps of:

preparing, at said outside node, a user-resource identifier query that includes an inside node identifier as well as said multiplexing information including at least one of outside node address information and inside node port information;

determining inside-realm network address information based on said inside node identifier included in said identifier query;

selecting, based on said multiplexing information included in said identifier query, said outside-realm gateway address to be used in establishing a dynamic gateway

connection state for a flow between said outside node and said inside node through said gateway; and

establishing said dynamic gateway connection state based on said selected outside-realm gateway address, said multiplexing information included in said identifier query and said inside-realm network address information, thereby enabling an outside-realm initiated connection.

16. The method according to claim 15, wherein said step of establishing said dynamic gateway connection state comprises the steps of:

creating a partially complete gateway connection state based on said selected outside-realm gateway address, said multiplexing information included in said identifier query and said inside-realm network address information; and

upon receipt of a packet from said outside node to said gateway, transforming said partially complete gateway state into a complete gateway connection state based on complementary connection information associated with said packet.

17. The method according to claim 16, wherein said multiplexing information included in said identifier query is an outside network address of said outside node, and said complementary connection information for completing the gateway connection state includes a port number of said inside node and a port number of said outside node.

18. The method according to claim 16, wherein said multiplexing information included in said identifier query is an inside node port number, and said complementary connection information for completing the gateway connection state

includes an outside network address of said outside node and a port number of said outside node.

19. The method according to claim 15, wherein said step of selecting an outside-realm gateway address comprises the step of selecting an outside-realm gateway address, which in combination with said multiplexing information included in said identifier-query defines a partially complete outside-realm gateway state representation that has no counterpart in any existing partially complete gateway connection state.

20. The method according to claim 19, further comprising the step of maintaining a separate list representation of existing partially complete gateway connection states, and wherein said partially complete outside-realm representation is

allocated based on comparison with corresponding information of all existing partially complete gateway connection states represented in said list representation.

21. The method according to claim 20, wherein outside-realm gateway addresses associated with said gateway are traversed until finding an outside-realm gateway address, which in combination with said multiplexing information included in said identifier query has no counterpart in any existing partially complete gateway connection state represented in said list representation.

22. The method according to claim 20, wherein said step of determining whether the combination of the selected candidate outside-realm gateway address and said multiplexing information is already being utilized for a connection comprises the step of verifying that a pre-allocated outside-realm gateway address in combination with said multiplexing information included in said identifier query has no counterpart in any existing partially complete gateway connection state represented in said list representation.

23. The method according to claim 15, further comprising the step of notifying said outside node of said selected outside-realm gateway address.

24. The method according to claim 15, wherein said user-resource identifier query is a Domain Name Server (DNS) query.

25. The method according to claim 15, wherein said inside address realm is a private address realm and said outside address realm is a public address realm.

26. A device for supporting establishment of a requested connection between a node of an inside address realm and a node of an outside address realm through an intermediate communication gateway having a gateway address pool comprising a limited number of available outside-realm gateway addresses for enabling outside-realm representation of inside-realm nodes, said device comprising:

i) means for providing multiplexing information including at least one of network address information and port information of at least one of said inside-realm node and said outside-realm node;

ii) means for network address allocation to determine an outside-realm gateway address based on a unique combination of one of said limited number of outside-realm gateway addresses and said multiplexing information, said network address allocation means being configured, prior to initiating establishment of said requested connection, for;

selecting, from said gateway address pool, a candidate outside-realm gateway address for combination with said multiplexing information,

determining whether the combination of the selected candidate outside-realm gateway address and said multiplexing information is already being utilized for another connection;

repeating, if the combination of the selected candidate outside-realm gateway address and said multiplexing information is already being utilized for another connection, the selection of outside-realm gateway address until a unique combination is found that is not already being utilized for another connection,

wherein the unique combination of outside-realm gateway address and said multiplexing information defines an outside-realm gateway state representation that has no counterpart in a predetermined set of existing gateway connection states, and said network address allocation means is configured for determining whether the combination of the selected candidate outside-realm gateway address and said multiplexing information is already being utilized for another connection based on a comparison in relation to said predetermined set of existing gateway connection states,

wherein said multiplexing information, for an inside-realm initiated connection, includes at least one of outside node address information and outside node port information, said outside-realm gateway state representation is an at least partially complete gateway state representation, and said predetermined set of gateway connection states includes the existing gateway connection states in said gateway; and

iii) means for initiating establishment of said requested connection based on the unique combination of outside-realm gateway address and said multiplexing information.

27. The device according to claim 26, further comprising means for maintaining a separate list representation of said predetermined set of existing gateway connection states, and wherein said network address allocation means is configured for finding said outside-realm gateway state representation based on comparison with corresponding information of said gateway connection states represented in said list representation.

28. The device according to claim 26, wherein said network address allocation means is configured for selecting also associated gateway port information for combination with said multiplexing information, said outside-realm representation is a complete outside-realm representation, and said means for initiating establishment of said connection comprises means for requesting that said gateway creates a gateway connection state based on said complete outside-realm representation.

29. The device according to claim 26, wherein said outside-realm representation is a partially complete outside-realm representation, and said means for initiating establishment of said connection comprises means for requesting that said gateway creates a partially complete gateway connection state based on said partially complete outside-realm representation.

30. A device for supporting establishment of a requested connection between a node of an inside address realm and a node of an outside address realm through an intermediate communication gateway having a gateway address pool comprising a limited number of available outside-realm gateway addresses for enabling outside-realm representation of inside-realm nodes, said device comprising:

i) means for providing multiplexing information including at least one of network address information and port information of at least one of said inside-realm node and said outside-realm node;

ii) means for network address allocation to determine an outside-realm gateway address based on a unique combination of one of said limited number of outside-realm gateway addresses and said multiplexing information, said network address allocation means being configured, prior to initiating establishment of said requested connection, for;

selecting, from said gateway address pool, a candidate outside-realm gateway address for combination with said multiplexing information,

determining whether the combination of the selected candidate outside-realm gateway address and said multiplexing information is already being utilized for another connection;

repeating, if the combination of the selected candidate outside-realm gateway address and said multiplexing information is already being utilized for another connection, the selection of outside-realm gateway address until a unique combination is found that is not already being utilized for another connection,

wherein the unique combination of outside-realm gateway address and said multiplexing information defines an outside-realm gateway state representation that has no counterpart in a predetermined set of existing gateway connection states, and said network address allocation means is configured for determining whether the combination of the selected candidate outside-realm gateway address and said multiplexing information is already being utilized for another connection based on a comparison in relation to said predetermined set of existing gateway connection states,

wherein said multiplexing information, for an outside-realm initiated connection, includes at least one of outside node address information and inside node port information, said outside-realm gateway state representation is a partially complete gateway state representation and said predetermined set of gateway connection states includes the existing partially complete gateway connection states in said gateway; and

iii) means for initiating establishment of said requested connection based on the unique combination of outside-realm gateway address and said multiplexing information.

31. The device according to claim 30, wherein said network address allocation means is configured for traversing outside-realm gateway addresses of the gateway until finding an outside-realm gateway address, which in combination with said multiplexing information has no counterpart in any existing partially complete gateway connection state.

32. The device according to claim 30, wherein said means for determining whether the combination of the selected candidate outside-realm gateway address and said multiplexing information is already being utilized for a connection comprises means for verifying that a pre-allocated outside-realm gateway address in combination with said multiplexing information has no counterpart in any existing partially complete gateway connection state.

33. The device according to claim 30, wherein said means for initiating establishment of said connection comprises means for requesting that said gateway establishes a partially complete gateway connection state based on said partially complete outside-realm representation.

34. The device according to claim 33, further comprising means for transforming, upon receipt of a packet from said outside node to said gateway, said partially complete gateway connection state that has been created in said gateway into a complete gateway connection state based on complementary connection information associated with said packet.

35. The device according to claim 34, wherein said multiplexing information is predetermined outside node address information, and said complementary connection information includes inside node port information and outside node port information.

36. The device according to claim 34, wherein said multiplexing information is predetermined inside node port information, and said complementary connection information includes outside node address information and outside node port information.

37. The device according to claim 30, further comprising means for selecting, if it is not possible to find a unique combination based on predetermined inside node port information, another gateway port, and means for selecting an

outside-realm gateway address based on said selected gateway port to define a unique, partially complete outside-realm representation of a gateway connection state.

38. The device according to claim 30, wherein said multiplexing information originates from a user-resource identifier query initiated from said outside node.

39. The device according to claim 30, wherein said means for initiating establishment of said connection is configured to operate based on said outside-realm gateway state representation and a corresponding inside-realm gateway state representation.

40. The device according to claim 30, further comprising:

means, responsive to a user-resource identifier query from said outside node, for determining inside-realm network address information based on an inside node identifier included in said identifier query, wherein said identifier query further includes said multiplexing information including at least one of outside node address information and inside node port information;

means for selecting, based on said multiplexing information included in said identifier query, said outside-realm gateway address to be used in establishing a dynamic gateway connection state for a flow between said outside node and said inside node through said gateway; and

means for establishing said dynamic gateway connection state based on said selected outside-realm gateway address, said multiplexing information included in said identifier query and said inside-realm network address information, thereby enabling an outside-realm initiated connection.

41. The device according to claim 40, wherein said means for establishing said dynamic gateway connection state comprises:

means for creating a partially complete gateway connection state based on said selected outside-realm gateway address, said multiplexing information included in said identifier query and said inside-realm network address information; and

means for transforming, upon receipt of a packet from said outside node to said gateway, said partially complete gateway state into a complete gateway connection state based on complementary connection information associated with said packet.

42. The device according to claim 41, wherein said multiplexing information included in said identifier query is an outside network address of said outside node, and said complementary connection information for completing the gateway connection state includes a port number of said inside node and a port number of said outside node.

43. The device according to claim 41, wherein said multiplexing information included in said identifier query is an inside node port number, and said complementary connection information for completing the gateway connection state includes an outside network address of said outside node and a port number of said outside node.

44. The device according to claim 40, wherein said means for selecting an outside-realm gateway address is operable for selecting an outside-realm gateway address, which in combination with said multiplexing information included in said identifier-query defines a partially complete outside-realm gateway state representation that has no counterpart in any existing partially complete gateway connection state.

45. The device according to claim 44, further comprising means for maintaining a separate list representation of existing partially complete gateway connection states, and wherein said network address allocation means is configured for finding said partially complete outside-realm representation based on comparison with corresponding information of all existing partially complete gateway connection states represented in said list representation.

46. The device according to claim 45, wherein said network address allocation means is configured for traversing outside-realm gateway addresses associated with said gateway until finding an outside-realm gateway address, which in combination with said multiplexing information included in said identifier query has no counterpart in any existing partially complete gateway connection state represented in said list representation.

47. The device according to claim 45, wherein said means for determining whether the combination of the selected candidate outside-realm gateway address and said multiplexing information is already being utilized for a connection comprises means for verifying that a pre-allocated outside-realm gateway address in combination with said multiplexing information included in said identifier query has no counterpart in any existing partially complete gateway connection state represented in said list representation.

48. The device according to claim 40, further comprising means for notifying said outside node of said selected outside-realm gateway address.

49. The device according to claim 40, wherein said user-resource identifier query is a Domain Name Server (DNS) query.

50. The device according to claim 40, wherein said inside address realm is a private address realm and said outside address realm is a public address realm.

51. A gateway resource manager for a communication gateway that has a limited number of available outside-realm gateway addresses for enabling outside-realm representation of inside-realm nodes, said gateway resource manager comprising:

i) an input configured to receive multiplexing information including at least one of network address information and port information of at least one of said inside-realm node and said outside-realm node;

ii) network address allocation circuitry configured to determine an outside-realm gateway address based on a unique combination of one of said limited number of outside-realm gateway addresses and said multiplexing information, said network address allocation circuitry being configured to perform the following tasks prior to initiating establishment of a requested connection;

select, from said outside-realm gateway addresses, a candidate outside-realm gateway address for combination with said multiplexing information;

determine whether the combination of the selected candidate outside-realm gateway address and said multiplexing information is already being utilized for another connection;

repeat, if the combination of the selected candidate outside-realm gateway address and said multiplexing information is already being utilized for another connection, the selection of outside-realm gateway address until a unique combination is found that is not already being utilized for another connection,

wherein the unique combination of outside-realm gateway address and said multiplexing information defines an outside-realm gateway state representation that has no counterpart in a predetermined set of existing gateway connection states, and said network address allocation circuitry is configured for determining whether the combination of the selected candidate outside-realm gateway address and said multiplexing information is already being utilized for another connection based on a comparison in relation to said predetermined set of existing gateway connection states,

wherein said multiplexing information, for an inside-realm initiated connection, includes at least one of outside node address information and outside node port information, said outside-realm gateway state representation is an at least partially complete gateway state representation, and said predetermined set of gateway connection states includes the existing gateway connection states in said gateway; and

iii) resource allocation circuitry configured to initiate establishment of said requested connection based on the unique combination of outside-realm gateway address and said multiplexing information.

52. The gateway resource manager according to claim 51, wherein said network address allocation circuitry is configured for finding said outside-realm gateway state representation based on comparison with corresponding information of said gateway connection states represented in a list representation of said predetermined set of existing gateway connection states.

53. A gateway resource manager for a communication gateway that has a limited number of available outside-realm gateway addresses for enabling outside-realm representation of inside-realm nodes, said gateway resource manager comprising:

i) an input configured to receive multiplexing information including at least one of network address information and port information of at least one of said inside-realm node and said outside-realm node;

ii) network address allocation circuitry configured to determine an outside-realm gateway address based on a unique combination of one of said limited number of outside-realm gateway addresses and said multiplexing information, said network address allocation circuitry being configured to perform the following tasks prior to initiating establishment of a requested connection;

select, from said outside-realm gateway addresses, a candidate outside-realm gateway address for combination with said multiplexing information;

determine whether the combination of the selected candidate outside-realm gateway address and said multiplexing information is already being utilized for another connection;

repeat, if the combination of the selected candidate outside-realm gateway address and said multiplexing information is already being utilized for another connection, the selection of outside-realm gateway address until a unique combination is found that is not already being utilized for another connection,

wherein the unique combination of outside-realm gateway address and said multiplexing information defines an outside-realm gateway state representation that has no counterpart in a predetermined set of existing gateway connection states, and said network address allocation circuitry is configured for determining whether the combination of the selected candidate outside-realm gateway address and said multiplexing information is already being utilized for another connection based on a comparison in relation to said predetermined set of existing gateway connection states,

wherein said multiplexing information, for an outside-realm initiated connection, includes at least one of outside node address information and inside node port information, said outside-realm gateway state representation is a partially complete gateway state representation and said predetermined set of gateway connection states includes the existing partially complete gateway connection states in said gateway; and

iii) resource allocation circuitry configured to initiate establishment of said requested connection based on the unique combination of outside-realm gateway address and said multiplexing information.

54. The gateway resource manager according to claim 53, wherein said input is configured to receive inside-realm network address information corresponding to an inside node, and multiplexing information including at least one of outside node address information and inside node port information;

said outside-realm gateway address is to be used in establishing a dynamic gateway connection state for a flow between said outside node and said inside node through said gateway;

said resource allocation circuitry is configured to request said gateway to establish said dynamic gateway connection state based on said selected outside-realm gateway address, said multiplexing information and said inside-realm network address information.

55. The gateway resource manager according to claim 54, wherein said multiplexing information is an outside node address, and said input is configured to request allocation of said selected outside-realm gateway address to said inside node for traffic coming from said outside node address.

56. The gateway resource manager according to claim 54, wherein said input is configured to send a request to said gateway for establishment of a partially complete gateway connection state based on said selected outside-realm gateway address, said multiplexing information and said inside-realm network address information.

57. The gateway resource manager according to claim 56, further comprising:

means for receiving a reply from said gateway that said partially complete gateway connection state has been created; and

means for notifying said outside node of said selected outside-realm gateway address in response to said reply from said gateway.

58. The gateway resource manager according to claim 56, wherein said network address allocation circuitry is configured to select an outside-realm gateway address, which in combination with said multiplexing information, defines a partially complete outside-realm gateway state representation that has no counterpart in any existing partially complete gateway connection state.

59. The gateway resource manager according to claim 58, further comprising means for maintaining a list representation of existing partially complete gateway connection states, and wherein said network address allocation circuitry is configured to find said partially complete outside-realm representation based on comparison with corresponding information of all existing partially complete gateway connection states represented in said list representation.

60. The gateway resource manager according to claim 53, wherein said network address allocation circuitry is configured to determine whether the combination of the selected candidate outside-realm gateway address and said multiplexing information is already being utilized for a connection based on comparison with established connections and/or connections under establishment.