Routing in a data communication network

• US 20060050692A1
• Filed: 10/08/2003
• Published: 03/09/2006
• Est. Priority Date: 10/09/2002
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola Mobility, Inc. (Lenovo Group Ltd.)
• Inventors: Petrescu, Alexandru, Lach, Hong-Yon, Janneteau, Christophe
• Granted Patent: US 7,706,301 B2
• Time in Patent Office: Days
• US Class Current: 370/389
• CPC Class Codes: H04L 2012/445 with switching in a hub, e.g. ETHERNET switch
• CPC Class Codes: H04L 61/5084 Providing for device mobility network addressing or numbering for mobility support in wireless networks H04W8/26; mobile IP H04W80/04
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04W 40/02 Communication route or path selection, e.g. power-based or shortest path routing
• CPC Class Codes: H04W 40/248 Connectivity information update
• CPC Class Codes: H04W 40/36 due to handover
• CPC Class Codes: H04W 8/02 Processing of mobility data, e.g. registration information at HLR [Home Location Register] or VLR [Visitor Location Register]; Transfer of mobility data, e.g. between HLR, VLR or external networks
• CPC Class Codes: H04W 8/087 for preserving data network PoA address despite hand-offs
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 80/00 Wireless network protocols or protocol adaptations to wireless operation
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]

Abstract

“A method of supporting mobility in an Internet Protocol (IP)-based data network. The method comprises the steps of generating a first stateful IP autoconfiguration message at a mobile node, whereby the message includes an address capable of use for routing maintenance. The mobile node transmits the generated message to a first access node, which incorporates its address and forwards the message to a dynamic host configuration protocol (DHCP) Server. The DHCP Server and access node analyse the message to determine a route to deliver data to and/or from the mobile node. One or more route update message are triggered from said access node and said DHCP server to a number of network elements between said access node and said DHCP server in the IP based data network to support mobility in an IP domain with minimum bandwidth use and minimum tunnelling required.”

Claims

1. A method of supporting mobility in an Internet protocol (IP)-based data network, the method characterised by the steps of:

generating a first stateful IP autoconfiguration message at a mobile node, wherein said message contains an address capable of use for route maintenance to/from said mobile node;

transmitting, by said mobile node, said generated message to a first access node, where said access node adds its address to said message;

forwarding said generated message, by an access node, to a dynamic host configuration protocol (DHCP) Server;

analysing said message, at said DHCP server, to determine a route to deliver data to and/or from said mobile node;

analysing said message, at said access node, to determine a route to deliver data to and/or from said mobile node; and

triggering one or more route update messages from said access node and said DHCP server to a number of network elements between said access node and said DHCP server in the IP based data network.

2. The method of supporting mobility according to claim 1, the method further characterised by the steps of:

repeating said steps of generating, transmitting and forwarding for a second stateful IP autoconfiguration message when said mobile node attaches to a second access node;

analysing said second message at said DHCP Server to determine that said second address used for route maintenance in said second message is inconsistent with said first address analysed in said first message; and

triggering a route update message based on said determination.

3. The method of supporting mobility according to claim 2, the method further characterised by the step of:

transmitting, in response to said determination, a deletion message to said first access node or said second access node and a number of network elements between said DHCP Server and said first access node or said second access node, where the deletion message instructs said number of network elements to delete obsolete address information used for route maintenance to/from said mobile node.

4. The method of supporting mobility according to claim 1, wherein said first and/or second stateful Internet Protocol autoconfiguration message is a DHCPv6 ‘

CONFIRM’

message.

5. The method of supporting mobility according to claim 1, wherein said address information used for route maintenance is based on a distance-vector routing protocol, for example the routing information protocol (RIP).

6. The method of supporting mobility according to claim 1, further characterised by the step of:

updating route maintenance information by a plurality of nodes in the IP-based data network, for example a DHCP Server, an access node such as a DHCP Relay or an Access router, and an intermediate router.

18. An IPv6 communication message transmitted from a DHCP Server to an access node via a number of routers, wherein the IPv6 communication message comprises route and/or address deletion instructions generated in accordance with claim 3.

19. A storage medium storing processor-implementable instructions for controlling a processor to carry out the method according to claim 1.

20. An apparatus adapted to perform the method steps according to claim 1.

7. An access node comprising:

a receiving function receiving at least one first Internet Protocol (IP) message from a mobile node, wherein said at least one first IP message comprises a mobile node address capable of use for route maintenance to deliver data to and/or from said mobile node; and

a processor, operably coupled to said receiving function, wherein said processor analyses said at least one first IP message, to determine a route to deliver data to and/or from said mobile node and triggers a transmission of one or more route update message from said access node to a number of network elements between said access node and a DHCP server in the IP based data network.

8. A dynamic host configuration protocol DHCP Server comprising:

a receiving function for receiving at least one first Internet Protocol (IP) message from a mobile node through a first access node, wherein said at least one first IP message comprises a number of addresses used for route maintenance to deliver data to and/or from said mobile node via said first access node; and

a processor, operably coupled to said receiving function, wherein said processor analyses said at least one first IP message, to determine a route to deliver data to and/or from said mobile node and triggers a transmission of one or more route update message from said DHCP server to a number of network elements between said access node and said DHCP server in the IP based data network.

9. The DHCP Server according to claim 8, wherein said DHCP Server receives and analyses at least one second IP message comprising a second set of addresses capable of use for route maintenance from said mobile node through a second access node, such that said processor analyses said at least one second IP message to determine whether said second set of addresses are consistent with said first set of addresses.

10. The DHCP Server according to claim 9, wherein said DHCP Server further characterised by said processor, in response to said determination, triggering a route update message to said first access node or triggering a route update message to said second access node to delete obsolete address information used for route maintenance to/from said mobile node.

11. The DHCP Server according to claims 8, wherein said at least one first IP message and said at least one second IP message are IPv6 messages.

12. The DHCP Server according to claims 9, wherein said at least one first IP message and/or said at least one second IP message is an IPv6 stateful autoconfiguration ‘

CONFIRM’

message.

13. The DHCP Server according to claims 8, the DHCP Server further characterised by:

a memory element, operably coupled to said processor, containing a router table for storing route maintenance information extracted from said first and/or second IP message.

14. A data communication network adapted to incorporate the DHCP Server of claim 8.

15. The data communication network according to claim 14, wherein said first access node and/or said second access node are Access Routers collocated with DHCPv6 Relay functions.

16. The data communication network according to claim 14, wherein the data communication network includes a number of routers located between said first access node and/or said second access node and said DHCP Server in a substantially tree-type topology.

17. The data communication network according to claim 14, wherein a communication link between said mobile node and said first access node and/or said second access node is a wireless access media communication link to facilitate a wireless link.

21. (canceled)

22. (canceled)