Patent ID: 6389016
Filing Date: 2002-05-14
Classification: H04L

Abstract:
A method for transporting data between a sending entity and a receiving entity over a data communication system wherein the sending entity divides data into a plurality of groups which are sequentially indexed with group numbers, each group is segmented into a plurality of packets which are sequentially indexed in each group with sequence numbers, the method comprising the steps of, by the receiving entity:receiving each packet transmitted over the data communication system; reading a group number identifying a group and a sequence number of the received packet; comparing the sequence number with an expected sequence number of the group; accepting the received packet for further processing when the sequence number of the received packet matches the expected sequence number; incrementing the expected sequence number of the group when the received packet is accepted; discarding the received packet when the sequence number of the received packet does not match the expected sequence number; setting a negative acknowledgment sent indicator when the packet is discarded and no negative acknowledgment sent indicator has been set for the group, the negative acknowledgment sent indicator indicating that a negative acknowledgment has been sent and the receiving entity is waiting for a packet with the expected sequence number; sending a negative acknowledgment when the sequence number of the received packet is greater than the expected sequence number and the negative acknowledgment sent indicator has not been set; sending a positive acknowledgment when the received packet is a last packet of the group and the sequence number of the received packet matches or smaller than the expected sequence number.