Mobile VPN proxy method based on session initiation protocol

• US 20060230445A1
• Filed: 04/06/2005
• Published: 10/12/2006
• Est. Priority Date: 04/06/2005
• Status: Abandoned Application

• Current Assignee: Zyxel Communications Corporation (Unizyx Holding Corporation)
• Original Assignee: Zyxel Communications Corporation (Unizyx Holding Corporation)
• Inventors: Huang, Shun-Chao
• Application Number:
  US11/099,508
• Publication Number:
  US 20060230445A1
• Time in Patent Office: Days
• US Class Current: 726/15
• CPC Class Codes: H04L 63/0272 Virtual private networks
• CPC Class Codes: H04W 12/033 of the user plane, e.g. user's traffic
• CPC Class Codes: H04W 12/04 Key management, e.g. using generic bootstrapping architecture [GBA]
• CPC Class Codes: H04W 12/041 Key generation or derivation
• CPC Class Codes: H04W 12/0431 Key distribution or pre-distribution; Key agreement
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]
• CPC Class Codes: H04W 80/10 adapted for application session management, e.g. SIP [Session Initiation Protocol] connection management H04W76/00; arrangements for session management H04L67/14

Abstract

A mobile VPN proxy method is based on an SIP communication protocol, whereby a mobile node (MN) roaming in a foreign network has secure communication with a communication node (CN) in a home network. A first SIP proxy server, an application level gateway (ALG), a second SIP proxy server and an AAA server are provided between the home network and the foreign network. The second SIP proxy server modifies a message transmission direction of an SIP/SDP message packet of the CN and sends the packet to the ALG, when the second SIP proxy server detects the MN intending to connect to the home network. The first SIP proxy server performs identification/authentication for the MN and generates a negotiation key to the ALG to establish a secure connection between the first SIP proxy server and the ALG. Moreover, the ALG takes over the communication between the MN and the CN.

Claims

1. A mobile VPN proxy method based on SIP communication protocol, the method applied to a home network and at least one foreign network such that a mobile node (MN) roaming in the foreign network has secure communication with a communication node (CN) in the home network, the method comprising the steps of:

a) providing a first SIP proxy server and an application level gateway (ALG) at a path between the home network and the foreign network;

b) providing a second SIP proxy server in the home network;

c) the second SIP proxy server modifying a message transmission direction of an SIP/SDP message packet of the CN and sending the SIP/SDP message packet to the ALG, when the second SIP proxy server detecting that the MN roaming in the foreign network intends to connect to the home network;

d) the first SIP proxy server performing identification and authentication for the MN and generating a negotiation key to the ALG in order to establish a secure connection between the first SIP proxy server and the ALG; and

e) the ALG taking over the communication between the MN and the CN.

2. The method as in claim 1, wherein in the step b) the second SIP proxy server provides secure function for message packet sent from the CN and sends the message packet to the ALG.

3. The method as in claim 1, wherein before the step c), the second SIP proxy server monitors each packet for each SIP session.

4. The method as in claim 1, wherein after the step d), the first SIP proxy server will response the SIP message packet completely and orderly to the CN when the MN located in the foreign network intends to roam to another foreign network, whereby a connection between he ALG and the CN is sustained.

5. The method as in claim 1, wherein in the step d), the first SIP proxy server performs the identification and authentication to generate the negotiation key through an Authentication, Authorization and Accounting (AAA) server.

6. The method as in claim 5, wherein the AAA server is placed between the first SIP proxy server and the second SIP proxy server.

7. The method as in claim 1, further comprising steps after the step d):

the first SIP proxy server commanding the ALG to reserve a sufficient resource for taking over the transmitting data; and

the ALG intervening an SIP message flow by responding a necessary result.

8. The method as in claim 1, wherein the MN and the CN are computers with wireless network equipment.

9. The method as in claim 1, wherein in the step a) the first SIP proxy server and the ALG are provided at edge of the home network.