Method and apparatus for connecting IPV6 devices through an IPv4 network and a network address translator (NAT) using a tunnel setup protocol

• US 20040133692A1
• Filed: 01/07/2003
• Published: 07/08/2004
• Est. Priority Date: 01/07/2003
• Status: Active Grant

• Current Assignee: Hexago, Inc. (gogo6, Inc.)
• Original Assignee: Hexago, Inc. (gogo6, Inc.)
• Inventors: Blanchet, Marc, Boudreault, Jean-Francois, Parent, Florent
• Granted Patent: US 7,305,481 B2
• Time in Patent Office: Days
• US Class Current: 709/230
• CPC Class Codes: H04L 61/251 between different IP versions
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04L 67/56 Provisioning of proxy services store-and-forward switching systems in data switching networks H04L12/54
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/167 Adaptation for transition between two IP versions, e.g. between IPv4 and IPv6 translation of Internet protocol [IP] addresses H04L61/2503
• CPC Class Codes: H04W 80/045 involving different protocol versions, e.g. MIPv4 and MIPv6

Abstract

A tunnel setup protocol enables tunnel clients to set up IPv6-in-IPv4 networks to permit IPv6 nodes to communicate across the IPv4 network using IPv6 native packets, even if the IPv4 network contains a Network Address Translation function. The tunnel setup protocol uses a control channel to negotiate tunnel configuration parameters and exchange tunnel configuration data between a tunnel client and a tunnel broker server. The tunnel setup is automatic, and migration to IPv6 is ameliorated.

Claims

1. A method for connecting IPv6 devices through an IPv4 network with network address translation (NAT) to an IPv6 node in an IPv6 network using a tunnel setup protocol (TSP) session, comprising steps of:

sending a message from a tunnel client in the IPv4 network to a tunnel broker server in the IPv4 network to establish a control channel with the tunnel broker server;

sending to the tunnel broker server, via the control channel, a request message to establish an IPv6-in-IPv4 tunnel through the IPv4 network, the request including tunnel configuration parameters desired by the tunnel client;

determining at the tunnel broker server whether there is NAT between the tunnel client and the tunnel broker server by examining information in the request message; and

receiving from the tunnel broker server, via the control channel, any one of;

an acceptance of the request with a specification of information respecting the tunnel configuration parameters desired by the tunnel client;

an acceptance of the request with a specification of at least one alternate parameter for the tunnel configuration desired by the tunnel client; and

, a refusal to establish the tunnel.

2. The method as claimed in claim 1 wherein the step of determining is performed by comparing a source address extracted from an IPv4 message encapsulating the request with an IPv4 tunnel client endpoint address specified in the request.

3. The method as claimed in claim 1 wherein after the control channel is established with the tunnel broker server, the method further comprises steps of:

sending from the tunnel client to the tunnel broker server a version of a tunnel session protocol installed on the tunnel client;

determining at the tunnel broker server whether the version of the tunnel session protocol is supported by the tunnel broker server; and

returning an error message if the version of the tunnel session protocol is not supported by the tunnel broker server.

4. A method as claimed in claim 3 wherein after the step of returning an error message, the method further comprises a step of returning, from the tunnel broker server to the tunnel client, a list of alternate tunnel broker servers to permit the tunnel client to attempt to obtain service from another tunnel broker server.

5. A method as claimed in claim 3 wherein if the tunnel broker server supports the version of the tunnel session protocol, the method further comprises a step of returning, from the tunnel broker server to the tunnel client, service capabilities of the tunnel broker server.

6. A method as claimed in claim 5 wherein the service capabilities comprise a specification of authentication types, and the method further comprises steps of selecting by the tunnel client an authentication type, and sending authentication information to the tunnel broker server to permit the tunnel broker server to verify that the client is authenticated for the service.

7. A method as claimed in claim 1 wherein the step of sending the message through the IPv4 network comprises a step of formulating either one of a Transfer Control Protocol (TCP) and an User Datagram Protocol (UDP) message that is sent to the tunnel broker server to establish the control channel.

8. A method as claimed in claim 1 wherein the step of sending the request comprises a step of formulating tunnel configuration parameters, comprising a tunnel action type, a tunnel type, and an IPv4 tunnel endpoint address.

9. A method as claimed in claim 8 wherein the tunnel configuration parameters further comprise a request for an IPv6 prefix of a specified length, and a domain name service (DNS) delegation and router peering.

10. A method as claimed in claim 1 wherein the step of receiving the acceptance from the tunnel broker server comprises a step of receiving information specifying a tunnel lifetime, a tunnel client endpoint IPv4 address, a tunnel client endpoint IPv6 address, a tunnel broker server endpoint IPv4 address, and a tunnel broker server endpoint IPv6 address, and an indication that the control channel is subject to NAT and the control channel must be used as the data channel.

11. A method as claimed in claim 10 wherein subsequent to receiving the information, the tunnel client further performs a step of closing the TSP session and configuring the tunnel client endpoint using the tunnel client endpoint IPv4 address and the tunnel client endpoint IPv6 address.

12. A method as claimed in claim 1 wherein prior to the step of sending an acceptance of the request with a specification of information respecting the tunnel configuration parameters desired by the tunnel client, the tunnel broker server performs a step of reserving a tunnel broker server endpoint.

13. A method as claimed in claim 12 wherein if the step of reserving the tunnel broker server endpoint is unsuccessful, the tunnel broker server returns an error message to the tunnel client, along with a refusal to establish the tunnel.

14. A method as claimed in claim 13 wherein the tunnel broker server further returns a list of alternate tunnel broker servers to the tunnel client, to permit the tunnel client to attempt to establish a tunnel using another tunnel broker server.

15. A method as claimed in claim 1 wherein after the tunnel client receives an acceptance of the request with a specification of information respecting the tunnel configuration parameters desired by the tunnel client, the tunnel client periodically sends a keep-alive message to the tunnel broker server to maintain the NAT state opened to preserve the tunnel.

16. Apparatus for connecting IPv6 devices through an IPv4 network with network address translation (NAT) to an IPv6 node in an IPv6 network using a tunnel setup protocol (TSP) session, comprising:

a tunnel broker server adapted to function as a tunnel broker, the tunnel broker server being programmed to;

respond to a message establishing a control channel with a tunnel client;

authenticate a tunnel client wishing to establish an IPv6-in-IPv4 tunnel through an IPv4 network to which the tunnel broker server is connected;

accept desired parameters for a configuration of the IPv6-in-IPv4 tunnel from the tunnel client;

determine if a NAT occurs between the tunnel client and the tunnel broker and inform the tunnel client of the NAT; and

configure a tunnel endpoint after receiving acknowledgement that the desired parameters for the configuration of the tunnel client have been accepted and the TSP session has been closed.

17. Apparatus as claimed in claim 16 wherein the tunnel broker server is further adapted to return to the tunnel client an encapsulation specification and parameters for a configuration of the IPv6-in-IPv4 tunnel after accepting the desired parameters from the tunnel client.

18. Apparatus as claimed in claim 16 wherein the tunnel broker server is adapted to return a list of other tunnel broker servers which may be used by the tunnel client, if the tunnel broker server is not adapted to provide service in accordance desired parameters for a configuration of the IPv6-in-IPv4 tunnel from the tunnel client.

19. Apparatus as claimed in claim 17 wherein the tunnel broker server is adapted to configure a tunnel end point after returning parameters for a configuration of the IPv6-in-IPv4 tunnel to the tunnel client and closing the TSP session.

20. Apparatus as claimed in claim 16 wherein the tunnel client is adapted to:

establish a control channel with the tunnel broker server;

provide authentication information to the tunnel broker server to permit the tunnel broker server to authenticate the tunnel client;

provide to the tunnel broker desired parameters for a configuration of the tunnel;

accept from the tunnel broker an encapsulation specification and parameters for the configuration of the tunnel;

configure a tunnel endpoint given the parameters for the configuration of the tunnel after acknowledging acceptance of the configuration of the tunnel and closing the TSP session; and

encapsulate packets to be sent through the tunnel using the encapsulation specification provided by the tunnel broker.

21. Apparatus as claimed in claim 20 wherein the tunnel client is a router and is further adapted to request an IPv6 prefix of a specified length when providing the tunnel broker server with the desired parameters for a configuration of the tunnel.

22. Apparatus as claimed in claim 20 wherein the tunnel client is adapted to configure itself as a tunnel endpoint.

23. Apparatus as claimed in claim 20 wherein the tunnel client is adapted to maintain a NAT state open by periodically sending keep-alive messages to the tunnel broker server after the tunnel client has configured the tunnel endpoint.

24. Apparatus as claimed in claim 23 wherein the tunnel client is adapted to encapsulate the keep-alive messages using tunnel setup protocol (TSP) over User Datagram Protocol (UDP) over IPv6 over UDP over IPv4.

25. A system for connecting IPv6 devices through an IPv4 network with network address translation (NAT) to an IPv6 node in an IPv6 network using a tunnel setup protocol (TSP), comprising:

a tunnel broker server and a tunnel client that function as respective nodes in the IPv4 network, the tunnel broker server being adapted to respond to a message sent from the tunnel client to establish a control channel between the tunnel client and the tunnel broker server, use the control channel to authenticate the tunnel client attempting to establish an IPv6-in-IPv4 tunnel through the IPv4 network, accept parameters for a configuration of the IPv6-in-IPv4 tunnel sent by the tunnel client via the control channel; and

the tunnel broker server and the tunnel client being respectively adapted to configure a tunnel endpoint for the IPv6-in-IPv4 tunnel, and set up the tunnel through the NAT using User Datagram Protocol (UDP) or Transport Control Protocol (TCP) over IPv4 after the tunnel parameters are negotiated and the TSP session is closed.

26. The system as claimed in claim 25 wherein the tunnel client is a host in the IPv4 network.

28. The system as claimed in claim 25 wherein the tunnel broker server is adapted to assign an IPv6 prefix to be used by the tunnel endpoint for a duration of the IPv6-in-IPv4 tunnel.

29. The system as claimed in claim 28 wherein the tunnel client is adapted to request the IPv6 prefix from the tunnel broker client.

27. The system as claimed in claim 31 wherein the tunnel client is a router having an IPv4 stack and an IPv6 stack, and at least one link to each of the IPv4 and IPv6 networks.