1. A method for controlling processing of messages for a plurality of protocol instances, comprising: receiving a plurality of messages for a plurality of processors, wherein each message is associated with one of the protocol instances; generating, for each message, a processing request identifying the one of the protocol instances with which the message is associated; queuing the processing requests using a respective plurality of queues associated with the protocol instances, wherein each processing request is queued in the queue associated with the one of the protocol instances with which the processing request is associated; and servicing the queues in a manner for arbitrating access by the queues to the processors for processing the messages, wherein each of the queues having at least one processing request queued therein is serviced by reading a processing request from the queue and causing the one of the processors with which the retrieved processing request is associated to process one of the messages associated with the protocol instance identified by the processing request.