| abstract |
An apparatus for measuring data transmission performance through a packet switched network, the apparatus having a time of day (TOD) clock for determining a send TOD timestamp, and for determining a present TOD when a data packet returns to the sending apparatus. The apparatus further comprising a counter that is incremented by a send sequence number each time data is sent, and one or more subtractors for calculating a first time difference between the send TOD timestamp and a receive TOD timestamp, and for calculating a second time difference between the receive TOD and the present TOD. Additionally, one or more comparators of the apparatus compare a sequence difference between the send sequence number and a receive sequence number in order to measure data transmission performance. |