Policy based mechanisms for selecting access routers and mobile context

Abstract

In mobile IP networks, when a mobile node (MN) moves from one cell to another, handover occurs. The result of the handover is that the MN connects to the network through a new access router (AR). The handover may occur between access routers of the same or different administrative domains. In all cases, the information related to the mobile node has to be transferred from the old AR to the new AR in order to minimize the effect of the change of access routers.

1 . A method comprising:
 receiving all contexts from a first policy server, wherein said all contexts comprise a context added with a second context;   extracting a relevant context from said all contexts;   forwarding a rest of context to a second policy server to extract a static context; and   wherein the static context is forwarded to at least one network element, and wherein a context transfer complete message is transmitted to a first access router and forwarded to the first policy server.   
   
   
       2 . The method of  claim 1 , wherein the first policy server is a component of a first autonomous system, and the second policy server is a component of a second autonomous system. 
   
   
       3 . The method of forwarding a context of  claim 1 , further comprising forwarding a context transfer request from the first policy server to a second autonomous system wherein the first policy server is a component of a first autonomous system. 
   
   
       4 . The method of forwarding a context of  claim 3 , further comprising requesting the first policy server to send a context transfer request. 
   
   
       5 . The method of forwarding a context of  claim 4 , further comprising receiving an identity packet at the first access router. 
   
   
       6 . A method comprising:
 identifying, to a mobile node currently served by a first autonomous system, a list of at least one capable access router, wherein the identifying comprises
 getting an identifier; 
 forwarding the identifier to a neighboring policy server; and 
 sending a message to the mobile node, said message having the list of at least one capable access router. 
   
   
   
       7 . The method of  claim 6 , further comprising:
 determining if a second autonomous system can serve the mobile node; and   calculating the list of at least one access router that can serve the mobile node.   
   
   
       8 . The method of  claim 6 , wherein the getting of the identifier comprises getting a link layer identifier. 
   
   
       9 . The method of  claim 6 , wherein the getting of the identifier comprises getting an autonomous system number. 
   
   
       10 . The method of  claim 9 , further comprising:
 determining if a second autonomous system can serve the mobile node; and   calculating the list of at least one access router that can serve the mobile node.   
   
   
       11 . An apparatus comprising:
 a receiver configured to receive all contexts from a first policy server, wherein said all contexts comprise a context added with a second context;   an extractor configured to extract a relevant context from said all contexts; and   a transmitter configured to forward a rest of context to a second policy server to extract a static context,   wherein the static context is forwarded to at least one network element, and wherein a context transfer complete message is transmitted to a first access router and forwarded to the first policy server.   
   
   
       12 . The apparatus of  claim 11 , further comprising a requester configured to request the first policy server to send a context transfer request. 
   
   
       13 . An apparatus comprising:
 an identifying unit configured to identify, to a mobile node currently served by a first autonomous system, a list of at least one capable access router, wherein the identifying unit comprises
 a retrieving unit configured to retrieve an identifier; 
 an identifier transmitter configured to forward the identifier to a neighboring policy server; and 
 a message transmitter configured to send a message to the mobile node, said message having the list of at least one capable access router. 
   
   
   
       14 . The apparatus of  claim 13 , further comprising:
 a determiner configured to determine if a second autonomous system can serve the mobile node; and   a calculator configured to calculate the list of at least one access router that can serve the mobile node.   
   
   
       15 . The apparatus of  claim 13 , wherein the retrieving unit is configured to retrieve a link layer identifier. 
   
   
       16 . The apparatus of  claim 13 , wherein the retrieving unit is configured to retrieve an autonomous system number. 
   
   
       17 . A computer program, embodied on a computer readable medium, the computer program configured to perform the following:
 receiving all contexts from a first policy server, wherein said all contexts comprise a context added with a second context;   extracting a relevant context from said all contexts; and   forwarding a rest of context to a second policy server to extract a static context,   wherein the static context is forwarded to at least one network element, and wherein a context transfer complete message is transmitted to a first access router and forwarded to the first policy server.   
   
   
       18 . A computer program, embodied on a computer readable medium, the computer program configured to perform the following:
 identifying, to a mobile node currently served by a first autonomous system, a list of at least one capable access router, wherein the identifying comprises
 getting an identifier; 
 forwarding the identifier to a neighboring policy server; and 
 sending a message to the mobile node, said message having the list of at least one capable access router. 
   
   
   
       19 . An apparatus comprising:
 receiving means for receiving all contexts from a first policy server, wherein said all contexts comprise a context added with a second context;   extracting means for extracting a relevant context from said all contexts; and   transmitting means for forwarding a rest of context to a second policy server to extract a static context,   wherein the static context is forwarded to at least one network element, and wherein a context transfer complete message is transmitted to a first access router and forwarded to the first policy server.   
   
   
       20 . An apparatus comprising:
 identifying means for identifying, to a mobile node currently served by a first autonomous system, a list of at least one capable access router, wherein the identifying means comprises
 retrieving means for retrieving an identifier; 
 identifier transmitting means for forwarding the identifier to a neighboring policy server; and 
 message transmitting means for sending a message to the mobile node, said message having the list of at least one capable access router.