Patent ID: 8694677

Claim:
A retry communication control method for a packet communication system that includes a plurality of packet transfer apparatuses each connected to a network and to at least one terminal apparatus and is capable of exchanging packets between the terminal apparatuses according to priority levels assigned to the packets, comprising: sending packets of a trial class for a predetermined period from a caller terminal apparatus; estimating whether or not a communication quality of the packets is sufficient; if it is sufficient, sending packets of a priority class thereafter; if it is insufficient, stopping to send packets of the trial class for a second predetermined period; after the second predetermined period, selecting one or more terminal apparatuses eligible to send packets of the trial class according to an execution probability, wherein the execution probability is equal to max/total, wherein “total” represents the number of terminal apparatuses trying to send packets of the trial class within a certain time unit, and “max” represents the maximum number of terminal apparatuses trying to send packets of the trial class within the certain time unit and allowed to successfully transfer the packets of the trial class without deteriorating communication quality, estimated from the communication quality of the preceding trial-class packets; and if the caller terminal apparatus is a terminal apparatus eligible to send packets of the trial class, again sending packets of the trial class for the predetermined period from the caller terminal apparatus.