Method for quick identification of special data packets
View Patent ↗In packetized data communication, certain special data packets must be identified quickly without the variable overhead of processing through the data protocol stack. A common example of such packets is those used for triggering events: immediate action must be taken on their arrival. This disclosure concerns a method for identifying such packets through the use of the error checking codes which are usually included in packet transmission protocols. By adding appropriate bits to a special data packet before transmission, the error checking code can be forced to a specific, predetermined sequence which will be recognized by error checking hardware at a receiver. If the specific sequence is all ones (or all zeros), the recognition hardware can be simplified.
1. In a data transmission system for transporting data packets created according to a defined data protocol for processing data, the protocol including
a) a process for computing an error detection code to be included in a packet transported by the system and
b) a process for detecting possible errors in the packet by utilizing such error detection code,
a method for tagging a special data packet, comprising the steps of:
1) examining the special data packet without the error detection code;
2) determining, from the examining step, additional data to be included with the special data packet in order to cause the error detection process to compute a predetermined sequence of error detection code; and
3) modifying the special data packet by including the additional data determined by the determining step.
2. A method for tagging a special data packet, as recited in claim 1 , in which the predetermined sequence is composed of identical symbols.
3. In a data transmission system for transporting data packets created according to a defined data protocol for processing data, the protocol including
a) a process for computing an error detection code to be included in a packet transported by the system and
b) a process for detecting possible errors in the packet by utilizing such error detection code,
a method for detecting a special data packet, comprising the steps of:
1) identifying, by reference to the data protocol, error detection code associated with a data packet;
2) comparing the error detection code with a predetermined sequence; and
3) determining the data packet to be a special tagged data packet when the comparing step results in a match.
4. A method for tagging a special data packet, as recited in claim 3 , in which the predetermined sequence is composed of identical symbols.
5. In a data transmission system for transporting data packets created according to a defined data protocol for processing data, a method for tagging a special data packet, comprising the steps of:
1) defining a subset of data within the special data packet, excluding any error correcting code contained in the packet;
2) by utilizing a suitable algorithm for generating a code sequence as a function of the data subset, determining what additional data which, when added to the subset, causes the algorithm to generate a predetermined code sequence; and
3) adding the additional data to the data packet.
6. A method for tagging a special data packet, as recited in claim 5 , in which the predetermined sequence is composed of identical symbols.
7. In a data transmission system for transporting data packets created according to a defined data protocol for processing data, a method for detecting a special data packet, comprising the steps of:
1) identifying a predefined subset of data within a trial data packet;
2) generating a code sequence as a function of the subset by utilizing a suitable algorithm;
3) comparing the generated code sequence with a predetermined sequence; and
4) identifying the trial data packet as a special data packet when the comparing step results in a match.
8. A method for detecting a special data packet, as recited in claim 7 , in which the predetermined sequence is composed of identical symbols.