Packet data processing apparatus and packet data processing method

A packet data processing program for processing a packet data stream received by a computer system through a packet-switched network, wherein:

• said packet data processing program is read and executed by said computer system, to implement:
• a buffer for temporarily storing packet data that constitute said packet data stream received through said packet-switched network;
• a processing unit for sequentially reading and processing packet data stored in said buffer;
• and
• a monitoring unit for monitoring a state of said buffer periodically;
• on said computer system;
• and
• said monitoring unit comprises:
• an underflow or overflow processing part which periodically judges whether the buffer is in a state of underflow or overflow, and if the buffer is in the state of underflow or overflow, performs a process to have an amount of data stored in the buffer to be equivalent to a predetermined amount of data for absorbing transmission fluctuation, and
• a synchronous processing part which makes said processing unit skip at least one packet data to be read and processed next by said processing unit, if a number of the packet data stored in said buffer shows a tendency of increasing from a predetermined number of packet data, successively a given number of times;
• and
• which makes said processing unit suspend operation during a period of time required for reading and processing at least one packet data, if the number of the packet data stored in said buffer shows a tendency of decreasing from the predetermined number of packet data, successively the given number of times.

A packet data processing method for processing a packet data stream received through a packet-switched network, comprising:

• a storing step in which packet data constituting said packet data stream are received from said packet-switched network and stored temporarily in a buffer;
• a processing step in which packet data stored in said buffer are sequentially read and processed;
• and
• a monitoring step in which a state of said buffer is monitored periodically;
• and
• said monitoring step comprises:
• performing in an underflow or overflow processing part which periodically judges whether the buffer is in a state of underflow or overflow, and if the buffer is in the state of underflow or overflow, a process to have an amount of data stored in the buffer to be equivalent to a predetermined amount for absorbing transmission fluctuation, and
• making, by a synchronous processing part, said processing unit skip at least one packet data to be read and processed next by said processing unit, if a number of the packet data stored in said buffer shows a tendency of increasing from a predetermined number of data, successively a given number of times, and making said processing unit suspend operation during a period of time required for reading and processing at least one packet data, if the number of the packet data stored in said buffer shows a tendency of decreasing from the predetermined number of packet data, successively the given number of times.