Patent ID: 7710888

Claim:
In an access network, a method for performing loopback testing at the data link layer comprising: creating a data link layer loopback test pattern data flow comprising one or more test frames with a test frame originator device having a source management address; sending the data link layer loopback test pattern data flow over a communications link to a receiving port, wherein the communications link carries the data link layer loopback test pattern data flow concurrently with one or more customer data flows, thereby allowing a data link layer loopback test to be performed without taking the communications link out of service; receiving the data link layer loopback test pattern data flow at the receiving port; reading at least an address portion of the test frames at the receiving port by comparing the source management address of the test frames to the receiving port address; returning the test frames to the test frame originator device if the test frames are recognized as part of a data link layer loopback test pattern data flow; and analyzing the returned test frames at the test frame originator device, wherein the test frame originator device determines the performance of a portion of the access network based on the analysis.