Packet forwarding methods for use in handoffs

• US 20030193912A1
• Filed: 05/07/2003
• Published: 10/16/2003
• Est. Priority Date: 02/04/2002
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: OʼNeill, Alan
• Granted Patent: US 8,649,352 B2
• Time in Patent Office: Days
• US Class Current: 370/331
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04L 63/0892 by using authentication-authorization-accounting [AAA] servers or protocols
• CPC Class Codes: H04W 12/062 Pre-authentication
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 60/00 Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration
• CPC Class Codes: H04W 60/005 Multiple registrations, e.g. multihoming
• CPC Class Codes: H04W 8/20 Transfer of user or subscriber data
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]

Abstract

Extending Mobile IP (MIP) to support both local and remote access by using two MIP client stacks in the end node, a roaming Node in the local access network, a standard Home Agent in the remote network is described. Messages between the access node and the mobile node, and between the internal modules of the mobile node are used to control hand-off for each of multiple MIP clients operating in parallel in the mobile node and to enable backwards compatibility with legacy remote access clients.

Claims

1. A method of processing packets addressed to a HoA included in a packet flow, said method comprising:

operating a first node serving as a Home Agent to add an additional destination address field including an oRoA, to perform a first redirection operation on the packet flow to an oRN to produce a first redirected packet flow;

operating an oRN to receive said first redirected packet flow and to perform a second redirection to a CoA based on a binding table including an entry associating said CoA with said oRoA, said second redirection producing a second redirected packet flow; and

operating an AN, to receive said second packet flow or a third redirected packet flow and to perform a fourth redirection operation redirecting said received second or third redirected packet flow as flow to an end node as a function of an entry in a binding table, wherein said CoA in the oRN is one of a group of CoAs including a nRoA at a nRN and a MSCoA at a nAN and a CCoA at a nAN and a SHCoA at a nAN and a MSCoA at an oAN and a CCoA at an oAN and a SHCoA at an oAN.

2. The method of claim 1,

wherein said CoA is one of a SHCoA at a nAN and a SHCoA at an oAN;

wherein performing a second redirection to a CoA performed at said oRN includes adding the CoA associated with said oRoA to packets included in said received first redirected packet flow;

wherein said fourth redirection operation performed by said AN, includes removing the added CoA and forwarding the packet based on the oRoA destination address.

3. The method of claim 1,

wherein said CoA is one of a MSCoA at a nAN, a CCoA at a nAN, a MSCoA at an oAN and a CCoA at an oAN;

wherein performing a second redirection to a CoA performed at said oRN includes adding the CoA associated with said oRoA to packets included in said received first redirected packet flow;

wherein said fourth redirection operation performed by said AN includes forwarding the packet based on the CoA.

4. The method of claim 1,

wherein packets in said first redirected packet flow include a destination address equal to the oRoA;

and

wherein performing a second redirection to a CoA performed at said oRN includes replacing the included oRoA destination address with one of a MSCoA at a nAN, a CCoA at a nAN, a MSCoA at an oAN and a CCoA at an oAN; and

wherein said fourth redirection operation performed by said AN includes forwarding the packet based on the CoA.

5. The method of claim 1,

wherein packets in said first redirected packet flow include a destination address equal to the oRoA;

wherein the CoA is equal to a nRoA associated with a nRN, and

wherein said second redirection to a CoA performed at the oRN includes one of i) removing the destination address equal to the oRoA and replacing it with the CoA and ii) adding the CoA to the packets in the first redirected flow, before forwarding the packets as second redirected flow to the CoA equal to the nRoA, and

wherein said nRN receives said second redirected packets,

operating the nRN to perform a third redirection to a CoA associated with a nAN, said nAN CoA being one of a group including a SHCoA and a MSCoA.

6. The method of claim 5,

wherein the third redirection at the nRN produces a third redirected flow, the performing of said third redirection including one of i) removing the destination address equal to the nRoA and replacing it with the CoA and ii) adding the CoA to the packets in the second redirected flow, and iii) forwarding the third redirected packets to the CoA, and

wherein said oRN, nRN and nAN redirections are managed by a redirection routine.

7. The method of claim 1 wherein

the oRN compares received packets against a binding table and performs at least one of a group of processes on a received packet, said processes including i) a check that the packet was redirected by a HA whose address was registered into the binding entry associated with an oRoA destination address and ii) that the HoA destination address contained in the packet received at the oRN is registered in the binding table entry for said oRoA.

8. The method of claim 7

wherein the binding table entry in the oRN identifies a list of processes to be performed on a packet, said list being from a group of processes including i)redirecting the packet and ii) comparing the packet to firewall state to drop an unwanted packet and iii) modifying the packet diff-serv header value in either the received or second redirected packet and iv) modifying a counter associated with one of the oRoA and HoA and HA of the received packet and v) applying a Network Address Translation to the oRoA of the received or redirected packet if said oRoA address is a public address at the oRN but is at private address at the AN, and vi) undertaking a MIP NAT Traversal for said packet.

9. The method of claim 1

wherein operating an oAN to perform a fourth redirection operation to an end node additionally includes a redirection to a CoA at a nAN as redirected flow, as a function of an entry in a binding table, wherein said CoA at the nAN is one of a nCCoA, a SHCoA and a MSCoA, and

operating said nAN to perform a fifth redirection to the end node.

10. The method of claim 1

wherein the oRN receives packets from a CN that has a destination address equal to the oRoA,

wherein the oRN further redirects said packets to a CoA based on a binding table including an entry associating said CoA with said oRoA, said redirection being included as an additional packet flow in said second or third redirected packet flow;

and

operating an AN to receive a second or third redirected packet flow and to perform on the additional packet flow one of a group of checks associated with a binding entry including i) a check to ensure it is a local access flow and ii) a check to ensure it is received from a registered oRN with address RN1 and iii) a check to ensure it is received from a registered CN,

operating the AN to drop packets that fail a check, and

operating the AN′

to perform a process list associated with said binding entry before forwarding the packet to the end node.

11. The method of claim 1

wherein the HoA or the RoA that is assigned to the end node can be used as the source address of reverse packets towards a CN, and

wherein the AN′

and RN are operated to use the registered CoAs and, associated binding table entries and redirection methods in the AN and RN, to reverse tunnel said reverse packets via at least one of said AN and the RN, said mode of reverse tunneling.