Avoiding delayed data

A method for selectively transmitting data onto a network from a data processing system supporting at least one application and a network interface device, the at least one application being operable to transmit data over a network by means of the network interface device, the method comprising:

• forming data for transmission at an application;
• generating a timestamp and associating the timestamp with the data for transmission;
• subsequently, forming the data for transmission into one or more network messages for transmission over the network, the one or more network messages being associated with the timestamp;
• and
• immediately prior to the one or more network messages being transmitted onto the network, checking the timestamp to determine the time elapsed from the time represented by the timestamp and, if the time elapsed is greater than a maximum period, causing the one or more network messages to be discarded.

A method for avoiding retransmission of network messages at a data processing system supporting an application and a network protocol stack operable to transmit network messages in accordance with a network communication protocol supporting message retransmission, the method comprising:

• forming a network message from data provided by an application;
• the application indicating that retransmissions are to be disabled in respect of the network message;
• the network protocol stack causing the network message to be transmitted over a network connection;
• and
• on the expiry of a retransmission period without an acknowledgement being received at the network protocol stack in respect of the transmitted network message, the network protocol stack discarding the network message and abandoning the message retransmission.

A method for filtering data in a communication system comprising first and second data processing systems connected to a network, each of the first and second data processing systems supporting an application and a network interface device, the method comprising:

• at a first data processing system:
• signaling to a second data processing system a first maximum period;
• forming a network message from data provided by an application of the first data processing system, the network message including a timestamp;
• and
• a network interface device of the first data processing system transmitting the network message over a network connection to the second data processing system;
• and at the second data processing system:
• receiving the network message;
• determining the time elapsed since the time represented by the timestamp;
• and
• if the time elapsed since the time represented by the timestamp exceeds the first maximum period, discarding the network message.