Abstract: An arrangement is provided for detecting a matching DSL data link layer protocol. A matching-protocol detection mechanism is triggered under certain condition. The matching-protocol detection mechanism, once triggered, detects a matching protocol from at least one initiating protocol. The matching protocol is supported by both a customer premise equipment and a digital subscriber line access module and is used by both to establish a DSL connection. When the matching protocol is successfully identified, it is activated. When the matching protocol is not found, a failure is reported.