Variable aaa load distribution for pdsn

Abstract

A packet data serving node (PDSN) manages sessions between mobile devices and a packet-based network. The PDSN sends requests to and receives responses from an authentication, authorization, and accounting (AAA) server. The PDSN includes a packet session manager configured to create, maintain, and terminate the sessions between mobile devices and the packet-based network. The PDSN also includes a global AAA manager configured to determine latency in communication between the PDSN and the AAA server based on latencies of responses to at least two requests which the PDSN sends to the AAA server. The global AAA manager determines an adjustment in a load which may be imposed on the AAA sever based on the determined latency and causes the determined adjustment in the load which may be imposed on the AAA server to be implemented.

1 . A method comprising steps of
 managing through a packet data serving node (PDSN) packet communication sessions of mobile stations through a network, the managing step including:
 (a) sending from the PDSN requests to an authentication, authorization, and accounting (AAA) server for authentication, authorization, and/or accounting services with regard to the packet communication sessions of the mobile stations, and 
 (b) receiving responses to the requests from the AAA server; 
   based on latencies of responses received from the AAA server, determining a latency in communication between the PDSN and the AAA server; and   adjusting number of requests for authentication, authorization, and/or accounting services with regard to the packet communication sessions sent from the PDSN to the AAA server based on the latency in communication between the PDSN and the AAA server.   
     
     
         2 . The method of  claim 1 , wherein the adjusting step comprises directing a portion of future requests for authentication, authorization, and/or accounting services with regard to the packet communication sessions sent from the PDSN to an alternate AAA server, to reduce load on the AAA server. 
     
     
         3 . The method of  claim 1 , wherein the adjusting step comprises directing a portion of future requests for authentication, authorization, and/or accounting services with regard to the packet communication sessions sent from the PDSN to the AAA server, instead of to an alternate AAA server, to increase load on the AAA server. 
     
     
         4 . The method of  claim 1 , wherein the adjusting step is responsive to determination of a relationship of the latency in communication between the PDSN and the AAA server relative to one of a set of pre-determined latency threshold values. 
     
     
         5 . The method of  claim 4 , wherein the adjusting step is responsive to the latency in communication between the PDSN and the AAA server reaching or exceeding the one threshold value. 
     
     
         6 . The method of  claim 5 , wherein the adjusting step comprises directing a portion of future requests for authentication, authorization, and/or accounting services with regard to the packet communication sessions sent from the PDSN to an alternate AAA server, to reduce load on the AAA server, when the latency in communication between the PDSN and the AAA server reaches or exceeds the one threshold value. 
     
     
         7 . The method of  claim 4 , wherein the adjusting step is responsive to the latency in communication between the PDSN and the AAA server falling to or below the one threshold value. 
     
     
         8 . The method of  claim 7 , wherein the adjusting step comprises directing a portion of future requests for authentication, authorization, and/or accounting services with regard to the packet communication sessions sent from the PDSN to the AAA server, instead of to an alternate AAA server, to increase load on the AAA server, when the latency in communication between the PDSN and the AAA server falls to or below the one threshold value. 
     
     
         9 . The method of  claim 4 , further comprising a step of adjusting the number of requests for authentication, authorization, and/or accounting services with regard to the packet communication sessions sent from the PDSN to the AAA server based on a relationship of the latency in communication between the PDSN and the AAA server relative to a different one of the pre-determined latency threshold values. 
     
     
         10 . The method of  claim 9 , wherein the adjusting steps adjust the number of requests for authentication, authorization, and/or accounting services sent from the PDSN to the AAA server in discrete steps corresponding to successively higher ones of the pre-determined latency threshold values. 
     
     
         11 . The method of  claim 9 , wherein:
 for determined latency below a lowest of the pre-determined latency threshold values, there is no adjusting of requests authentication, authorization, and/or accounting services sent from the PDSN to the AAA server; and   as the adjusting steps correspond to successively higher ones of the pre-determined latency threshold values, the adjusting steps comprise directing successively higher portions of future requests for authentication, authorization, and/or accounting services with regard to the packet communication sessions sent from the PDSN to an alternate AAA server.   
     
     
         12 . The method of  claim 11 , wherein successively higher portions are not proportional to successively higher ones of the pre-determined latency threshold values. 
     
     
         13 . The method of  claim 1 , further comprising:
 repeatedly performing the determining and adjusting steps; and   waiting an amount of time after each performance of the adjusting step before performing the subsequent determining step.   
     
     
         14 . The method of  claim 1 , wherein the determining step comprises averaging the latencies of the responses received from the AAA server. 
     
     
         15 . The method of  claim 1 , wherein the determining step comprises treating each request from the PDSN to which no response is received from the AAA server within a pre-determined time as a response from the AAA server with a pre-determined latency. 
     
     
         16 . The method of  claim 1 , wherein the determining step comprises determining the latency in communication between the PDSN and the AAA server based on only most recent latency data for responses from the AAA server. 
     
     
         17 . The method of  claim 1 , wherein the determining step comprises determining the latency in communication between the PDSN and the AAA server based on a history of latency data for responses from the AAA server. 
     
     
         18 . The method of  claim 17 , wherein the determining step involves differently weighting of latency data from the history based on respectively different age of the latency data. 
     
     
         19 . The method of  claim 18 , wherein more recent latency data is weighted more heavily than older latency data from the history. 
     
     
         20 . A packet data serving node (PDSN), comprising:
 a processor;   a storage device; and   coded instructions for the processor, in the storage device,   wherein the coded instructions configure the PDSN to implement functions, including functions to:   manage packet communication sessions of mobile stations through a network, including to:
 (a) send from the PDSN requests to an authentication, authorization, and accounting (AAA) server for authentication, authorization, and/or accounting services with regard to the packet communication sessions of the mobile stations, and 
 (b) receive responses to the requests from the AAA server; 
   based on latencies of responses received from the AAA server, determine a latency in communication between the PDSN and the AAA server; and   adjust number of requests for authentication, authorization, and/or accounting services with regard to the packet communication sessions sent from the PDSN to the AAA server based on the latency in communication between the PDSN and the AAA server.   
     
     
         21 . A system, comprising:
 a radio communication network;   a packet data serving node (PDSN), comprising a processor and a memory device, configured to manage sessions of mobile devices through the radio communication network for communication with a packet-based network; and   first and second authentication, authorization, and accounting (AAA) servers,   wherein the PDSN is further configured to:   send requests to the first and second AAA servers for authentication, authorization, and/or accounting services with regard to the packet communication sessions of the mobile stations;   receive responses to the requests from the first and second AAA servers;   based on latencies of responses received from the first AAA server, determine a latency in communication between the PDSN and the first AAA server; and   adjust number of the requests sent to the first AAA server and number of the requests sent to the second AAA server, based on the latency in communication between the PDSN and the AAA server.