Patent ID: 7339889

Claim:
A method of determining an acceptability of a port for a connection in an Automatically Switched Optical Network, the port having a current port load, the method comprising: if the current port load is below a lower threshold, determining that the port is acceptable; if the current port load is above an upper threshold, determining that the port is not acceptable; and if the current port load is between the lower threshold and the upper threshold, determining whether the current port load was most recently above the upper threshold or below the lower threshold, and: if the current port load was most recently above the upper threshold, determining that the port is not acceptable; and if the current port load was most recently below the lower threshold, determining that the port is acceptable; wherein determining whether the current port load was most recently above the upper threshold or below the lower threshold comprises: maintaining a value of a flag by setting the value of the flag to a first value if the current port load falls below the lower threshold and setting the value of the flag to a second value if the current port load reaches the upper threshold; if the value of the flag is equal to the first value, determining that the current port load was most recently below the lower threshold; and if the value of the flag is equal to the second value, determining that the current port load was most recently above the upper threshold.