Patent ID: 8775628

Claim:
A system for balancing a SIP processing load, comprising: a memory and a processor; a load balancer in communication with the processor; and a plurality of server nodes, including: a first SIP server instance stored in the memory, the first SIP server instance arranged to handle one or more SIP processes during normal operation as an active server instance, and a second SIP server instance stored in the memory, the second SIP server instance arranged to act as a standby server instance during normal operation, the second SIP server instance being further arranged to take over the handling of said one or more SIP processes as an active server instance responsive to failure of the first SIP server instance, wherein the load balancer is arranged to assign a SIP process to an active SIP server instance, wherein, responsive to a second SIP server instance taking over the handling of one of more SIP processes previously handled by a first SIP server instance, the load balancer is arranged to assign new SIP processes to a group of active SIP server instances that excludes said second SIP server instance, wherein at least one active SIP server instance of the group of active SIP server instances that excludes said second SIP server instance is configured to provide a load factor value representative of a current resource usage associated with the active SIP server instance, and wherein the load balancer comprises: an interface for receiving said load factor value from said one active SIP server instance of the group of active SIP server instances; a loading calculator to determine a countdown value for the group of active SIP server instances based on the load factor value; and a load assigner for selecting a SIP server instance of the group of active SIP server instances and assigning a SIP process to the selected SIP server instance if said countdown value is above a predetermined threshold, the countdown value for the selected SIP server instance being decremented after the SIP process is assigned.