The Frame Relay Forum has now completed its promised Frame Relay/Asynchronous Transfer Mode Permanent Virtual Circuit Network Interworking Agreement, enabling the transport of Frame Relay traffic, at speeds up to T1/E1, over an Asynchronous Transfer Mode backbone. The specification was developed with the help of the ATM Forum, as was a complementary effort – which is still under way – guaranteeing quality of service; this specification is expected to be agreed next month. Since Frame Relay is most efficient at speeds up to T1/E1 – and Asynchronous Transfer Mode comes into its own above these speeds – the specifications are seen as being particularly significant for Asynchronous Mode service providers, who will be able to transport users’ Frame Relay traffic over their wide area backbones, while not requiring users to invest in Asynchronous Mode customer premises equipment, which carries a price premium over Frame Relay equipment. It will also enable Frame Relay users to communicate directly with Asynchronous Transfer users across an Asynchronous Mode network, since the transport is invisible to Frame Relay end users. Frame Relay service features that are supported by the specification include variable length protocol data unit formatting and delimiting, error detection, connection multiplexing, loss priority indication, congestion indication – both forward and backward – and permanent virtual connection status management.
