Active Mode Internet Protocol Gateway Relocation in a Partial Meshed Deployment

• US 20080062871A1
• Filed: 06/14/2007
• Published: 03/13/2008
• Est. Priority Date: 07/10/2006
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Grayson, Mark
• Granted Patent: US 8,155,077 B2
• Time in Patent Office: Days
• US Class Current: 370/231
• CPC Class Codes: H04W 40/18 based on predicted events

Abstract

Methods, apparatuses and systems directed to facilitating optimized routing and mobility for communication sessions in partial mesh network deployments. According to one embodiment, routing a packet flow in a communication session includes facilitating a communication session between a first mobile node and a second mobile node. A packet flow from the first mobile node is received at a transient anchor of a visited network. The transient anchor establishes whether the packet flow is to be routed along an optimized path according to one or more routing rules. One or more of the routing rules may be based on the current cell location of the first mobile node relative to a mobility or radio coverage boundary associated with the transient anchor. For example, if the first mobile node is located at a cell near a radio coverage boundary that, if traversed, would not allow for handover of the communications session if optimized routing were used, optimized routing may not be employed for the communications session.

Claims

1. A method comprising

receiving, at a transient anchor of a visited network, a message from a first endpoint requesting initiation of a communications session between the first endpoint and a second endpoint;

identifying an access node to which the first endpoint is connected;

determining whether packet flows of the communications session are to be routed along an optimized path based, at least in part, on the location of the access node relative to a mobility border associated with the transient anchor; and

forwarding the packet flows of the communications session between the first end point and the second endpoint along the optimized path, if the packet flows are to be routed along the optimized path;

forwarding the packet flows of the communications session between the first end point and the second endpoint to a permanent anchor of a home network of the first endpoint, if the flows are not to be routed along the optimized path.

2. The method of claim 1 further comprising receiving from a home network policy server of the first endpoint associated with the transient anchor of the visited network one or more policy rules relating to a communications session between the first endpoint and the second endpoint.

3. The method of claim 2 configuring the transient anchor to forward the packet flows of the communications session between the first end point and the second endpoint along the optimized path, if the packet flows are to be routed along the optimized path;

configuring the transient anchor to forward the packet flows of the communications session between the first end point and the second endpoint to a permanent anchor of a home network of the first endpoint, if the flows are not to be routed along the optimized path.

4. The method of claim 1 wherein the mobility border is defined by a physical radio coverage border comprising individual radio coverage areas of a plurality of access nodes associated with the transient anchor.

5. The method of claim 1 wherein a cell topology map is associated with the transient anchor, the cell topology map defining the relative locations of access nodes having connectivity to the transient anchor;

the cell topology map further identifying one or more border access nodes of the access nodes at the border of the aggregate radio coverage area defined by the access nodes;

the topology map further identifying the border of border access nodes physically adjacent to the border nodes; and

wherein the determining step includes

determining that the optimized path is to be used for the communications session, if the identified access node is not a border access node or a border of border access node;

else, determining that a default path including the permanent anchor of a home network of the first endpoint is to be used for the communications session.

6. The method of claim 1 further comprising

forwarding the message to the home network of the first endpoint;

and

receiving from a home network policy server of a first endpoint associated with a transient anchor of a visited network one or more policy rides relating to the communications session between the first endpoint and a second endpoint.

7. The method of claim 1 further comprising

responsive to a roam event of the first endpoint from the identified access node to a second access node, conditionally signaling the home network of the first endpoint to re-negotiate a path for the communications session based at least in part on the location of the second access node relative to the mobility border associated with the transient anchor.

8. Logic encoded in one or more tangible media for execution and when executed operable to:

receive, at a transient anchor of a visited network, a message from a first endpoint requesting initiation of a communications session between the first endpoint and a second endpoint;

identify an access node to which the first endpoint is connected;

determine whether packet flows of the communications session are to be routed along an optimized path based, at least in part, on the location of the access node relative to a mobility border associated with the transient anchor; and

forward the packet flows of the communications session between the first end point and the second endpoint along the optimized path, if the packet flows are to be routed along the optimized path;

else, forwarding the packet flows of the communications session between the first end point and the second endpoint to a permanent anchor of a home network of the first endpoint.

9. The logic of claim 8 wherein the mobility border is defined by a physical radio coverage border comprising individual radio coverage areas of a plurality of access nodes associated with the transient anchor.

10. The logic of claim 8 wherein a cell topology map is associated with the transient anchor, the cell topology map defining the relative locations of access nodes having connectivity to the transient anchor;

the cell topology map further identifying one or more border access nodes of the access nodes at the border of the aggregate radio coverage area defined by the access nodes;

the topology map further identifying the border of border access nodes physically adjacent to the border nodes; and

wherein the logic is further operable to;

determine that the optimized path is to be used for the communications session, if the identified access node is not a border access node or a border of border access node;

else, determine that a default path including the permanent anchor of a home network of the first endpoint is to be used for the communications session.

11. The logic of claim 8 wherein the logic is further operable to

forward the message to the home network of the first endpoint;

and

receive from a home network policy server of a first endpoint associated with a transient anchor of a visited network one or more policy rules relating to the communications session between the first endpoint and a second endpoint.

12. The logic of claim 8 wherein the logic is further operable to

responsive to a roam event of the first endpoint from the identified access node to a second access node, conditionally signal the home network of the first endpoint to re-negotiate a path for the communications session based at least in part on the location of the second access node relative to the mobility border associated with the transient anchor.

13. The logic of claim 8 wherein the logic is further operable to receive from a home network policy server of the first endpoint associated with the transient anchor of the visited network one or more policy rules relating to a communications session between the first endpoint and the second endpoint.

14. The logic of claim 8 wherein the logic is further operable to

configure the transient anchor to forward the packet flows of the communications session between the first end point and the second endpoint along the optimized path, if the packet flows are to be routed along the optimized path;

configure the transient anchor to forward the packet flows of the communications session between the first end point and the second endpoint to a permanent anchor of a home network of the first endpoint, if the flows are not to be routed along the optimized path.

15. A method comprising

forwarding packet flows of a communications session between a first end point and a second endpoint along an optimized path, wherein the first endpoint is connected to a first access node associated with a transient anchor of a visited network;

responsive to a roam event of the first endpoint from the first access node to a second access node, conditionally signaling the home network of the first endpoint to re-negotiate a path for the communications session based at least in part on the location of the second access node relative to a mobility border associated with the transient anchor.

16. The method of claim 15 wherein the mobility border is defined by a physical radio coverage border comprising individual radio coverage areas of a plurality of access nodes associated with the transient anchor.

17. The method of claim 15 further comprising

accessing a cell topology map associated with the transient anchor, the cell topology map defining the relative locations of access nodes having connectivity to the transient anchor;

the cell topology map further identifying one or more border access nodes of the access nodes at the border of the aggregate radio coverage area defined by the access nodes;

the topology map further identifying the border of border access nodes physically adjacent to the border nodes; and

wherein the determining step includes

signaling the home network to re-negotiate the path, if the second access node is a border access node or a border of border access node.

18. The method of claim 15 further comprising

forwarding packet flows of a communications session between a first end point and a second endpoint to a permanent anchor of a home network of the first endpoint, wherein the first endpoint is connected to a first access node associated with a transient anchor of a visited network;

and

responsive to a roam event of the first endpoint from the first access node to a second access node, conditionally signaling an option to establish an optimized path for the communications session to the home network of the first endpoint based at least in part on the location of the second access node relative to a mobility border associated with the transient anchor.

19. Logic encoded in one or more tangible media for execution and when executed operable to:

forward packet flows of a communications session between a first end point and a second endpoint along an optimized path, wherein the first endpoint is connected to a first access node associated with a transient anchor of a visited network;

responsive to a roam event of the first endpoint from the first access node to a second access node, conditionally signal the home network of the first endpoint to re-negotiate a path for the communications session based at least in part on the location of the second access node relative to a mobility border associated with the transient anchor.

20. The logic of claim 19 wherein the mobility border is defined by a physical radio coverage border comprising individual radio coverage areas of a plurality of access nodes associated with the transient anchor.