Patent ID: 6853624

Claim:
A method for calibrating a propagation delay in a network trunk comprising the steps of: (a) providing a counter in each of first and second network switches in a network switch system; (b) each counter calculating a time period Ti that begins when the first network switch transmits a trunk package and marker to the second network switch and that ends when the first network switch receives a trunk package acknowledgement marker from the second network switch, and a time period Tt that begin when the second network switch receives the trunk package and the marker from the first network switch and that ends when the second network switch transmits an acknowledgement marker containing the trunk package back to the first network switch; (c) commanding the second network switch to append the time period Tt to the acknowledgement marker prior to sending the acknowledgement marker back to the first network switch; (d) reading out the time period Tt after the first network switch has received the acknowledgement marker; and (e) calculating a time delay Tx after reading out the time period Tt by an equation Tx=(Ti−Tt)2 wherein the time delay Tx is caused by sending the trunk package on each of a plurality of channels between the first and the second network switches.