Mobile IP supporting quality of service

1. A method of establishing a session between a correspondent node and a mobile node, the mobile node having a home address in a home network and being temporarily connected at a care-of address in a foreign network, the session being a quality of service session between the correspondent node and the mobile node, the method comprising the steps of:

generating, in the foreign network, a modified reply message of an Internet Protocol packet having a source address of the mobile node's care-of address in place of the mobile node's home address and having a destination address of the correspondent node;

transmitting the modified reply message to the correspondent node; and

receiving a modified request message in the foreign network, the modified reply message being generated in response to the receipt of the modified request message in the foreign network, the modified request message being created by replacing a destination address of a request message received in the home network with the mobile node's care-of address, the request message received in the home network having a source address of the correspondent node and a destination address of the mobile node's home address; and

wherein the quality of service session is an RSVP session, the request message is a Path message, and the modified reply message is a Reservation message.

2. The method of claim 1 ,

wherein the step of generating the modified reply message is carried out by a proxy device in the foreign network, the proxy device being associated with the mobile node; and

further comprising the steps of:

responsive to receipt of the modified request message at the proxy device, sending a quality of service indication signal to the mobile node, whereby the modified reply message is generated responsive to receipt of a quality of service acknowledgement from the mobile node.

3. The method of claim 1 , further comprising the steps of:

receiving, in the home network, the modified reply message;

creating a further modified reply message by replacing the source address with the mobile node's home address; and

transmitting the further modified reply message.

4. The method of claim 3 , wherein the correspondent node generates the request message and receives the further modified reply message.

5. The method of claim 3 , wherein:

the correspondent node is associated with a correspondent proxy device, whereby:

the correspondent proxy device generates the request message responsive to a quality of service request from the correspondent node; and

the correspondent proxy device generates a quality of service confirmation responsive to receipt of the further modified reply message.

6. The method of claim 1 , wherein the step of generating the modified reply message is carried out in the mobile node.

7. The method of claim 1 , in which the step of generating the modified reply message is carried out by a proxy device in the foreign network, the proxy device being associated with the mobile node.

8. The method of claim 1 wherein the step of generating the modified reply message comprises:

generating a reply message having a source address of the mobile node's home address and a destination address of the correspondent node; and

replacing the source address with the mobile node's care-of address, thereby generating the modified reply message.

9. A system configured to support a session, comprising:

a proxy device, in a foreign network, the proxy device being associated with a mobile node both having a home address in a home network and being temporarily connected at a care-of address in the foreign network, the proxy device being configured for generating a modified reply message of an Internet Protocol packet having a source address of the mobile node's care-of address in place of the mobile node's home address and having a destination address of a correspondent node, the session being a quality of service session between the correspondent node and the mobile node; and

wherein the quality of service session is an RSVP session and the modified reply message is a Reservation message; and

wherein the proxy device is configured to generate the modified reply message responsive to receipt of a modified request message in the foreign network, the modified request message being created by a home agent in response to receiving a request message having a source address of the correspondent node and a destination address of the mobile node's home address, the modified request message being created by the home agent by replacing the destination address of the request message received by the home agent with the mobile node's care-of address, the request message received by the home agent being a Path message.

10. The system of claim 9 , wherein the proxy device is located in the mobile node.

11. The system of claim 10 , further comprising the mobile node.

12. The system of claim 9 , wherein the proxy device is located outside the mobile node and coupled to the mobile node.

13. The system of claim 12 , further comprising the foreign network.

14. The system of claim 9 , wherein the system is a mobile IP environment.