Mobile terminating L2TP using mobile IP data

• US 6,452,920 B1
• Filed: 12/30/1998
• Issued: 09/17/2002
• Est. Priority Date: 12/30/1998
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Comstock, David R.
• Primary Examiner(s): Kizou, Hassan
• Assistant Examiner(s): Logsdon, Joe
• Application Number:
  US09/223,187
• Time in Patent Office: 1,357 Days
• Field of Search: 370/310, 370/328, 370/331, 370/351, 370/352, 370/389, 370/392, 370/400, 370/401, 370/465, 370/466, 370/469, 370/474, 370/901, 370/902, 370/912, 370/913, 370/349, 379/900, 379/901
• US Class Current: 370/349
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling
• 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 69/161 Implementation details of TCP/IP or UDP/IP stack architecture; Specification of modified or new header fields
• CPC Class Codes: H04L 69/168 specially adapted for link layer protocols, e.g. asynchronous transfer mode [ATM], synchronous optical network [SONET] or point-to-point protocol [PPP]
• CPC Class Codes: H04L 69/324 in the data link layer [OSI layer 2], e.g. HDLC
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]
• CPC Class Codes: Y10S 370/901 Wide area network

Abstract

In accordance with embodiments of the invention, Mobile IP binding information is used to deliver mobile terminating packets using layer-2 tunneling. When terminating packets destined for a mobile node are received by a home network for the mobile node, the Mobile IP binding is used to obtain the address of a foreign network to which the mobile node is attached. A Layer 2 Tunneling Protocol tunnel is created between the home network and the foreign network, and an outgoing L2TP call is made from the home network to the foreign network. A call is made from the foreign network to the mobile node, and a PPP session is established between the home network and the mobile node, via the Layer 2 Tunneling Protocol tunnel between the home network and the foreign network. After the PPP session is established the home network can optionally assign the mobile node a private IP address, and translate the home IP address labeling the terminating packets to the private IP address.

Claims

1. A data network, comprising:

a correspondent node;

a mobile node; and

a Mobile IP interface between the correspondent node and the mobile node, wherein the data network further comprises;

a home network of the mobile node;

a home agent within the home network;

a Layer 2 Tunneling Protocol Network Server within the home network;

a foreign network;

a foreign agent within the foreign network;

a Layer 2 Tunneling Protocol Access Concentrator within the foreign network;

a Layer 2 Tunneling Protocol interface between the Layer 2 Tunneling Protocol Network Server and the Layer 2 Tunneling Protocol Access Concentrator; and

a Point to Point Protocol interface between the home network and the mobile node through the Layer 2 Tunneling Protocol interface between the Layer 2 Tunneling Protocol Network Server and the Layer 2 Tunneling Protocol Access Concentrator.

2. The data network of claim 1, wherein at least one of the home network and the foreign network is an operator'"'"'s network.

3. The data network of claim 1, wherein at least one of the home network and the foreign network is an Internet Service Provider.

4. The data network of claim 1, wherein at least one of the home network and the foreign network is a corporate network.

5. A method for using Mobile IP binding information and Layer 2 Tunneling Protocol tunneling to route packets from a correspondent node to a mobile node, comprising the steps of:

receiving at a home network of the mobile node a packet from the correspondent node for routing to the mobile node through the home network, the home network corresponding to a destination address on the packet, wherein the destination address is a home address for the mobile node;

determining a care-of address corresponding to a foreign network using the home address and the Mobile IP binding information for the mobile node;

establishing a Layer 2 Tunneling Protocol tunnel between the home network and the foreign network;

making a call from the foreign network to the mobile node;

establishing a Point-to-Point Protocol session between the home network and the mobile node;

encapsulating the received packet in accordance with the Layer 2 Tunneling Protocol for transmission through the Layer 2 Tunneling Protocol tunnel from the home network to the foreign network; and

sending the encapsulated packet through the Layer 2 Tunneling Protocol tunnel from the home network to the foreign network.

6. The method of claim 5, further comprising the steps of:

receiving the encapsulated packet at the foreign network;

decapsulating the received packet; and

forwarding the decapsulated packet to the mobile node.

7. A method for transmitting data packets to a mobile node across at least one internetwork, comprising the steps of:

receiving at a home network of the mobile node a data packet bearing a first Internet Protocol address and intended for terminal delivery to the mobile node;

encapsulating the data packet and the first Internet Protocol address using Point to Point Protocol to create a first message capsule;

encapsulating the first message capsule with a second Internet Protocol address designating a foreign network connected to the mobile node to create a second message capsule in accordance with Layer 2 Tunneling Protocol;

forwarding the second message capsule from the home network to the foreign network via a Layer 2 Tunneling Protocol tunnel between the home network and the foreign network;

decapsulating the second message capsule at the foreign network to recover the first message capsule; and

forwarding the recovered first message capsule from the foreign network to the mobile node.

8. The method of 7, further comprising the step of determining the second Internet Protocol address based on Mobile IP binding information for the mobile node.

9. The method of 7, further comprising the step of determining the second Internet Protocol address based on the first Internet Protocol address.