Frame relaying is designed to eliminate much of the overhead that X.25 imposes on end user systems and on the packet switching network. The key differences b/w frame relaying and a conventional X.25 packet switching services, are:
- Call control signaling is carried on a separate logical connection from user data. Thus, intermediate nodes need not maintain state tables or process message relating to call control on an individual per-connection basis.
- Multiplexing & switching of logical connections take place at layer 2 instead of layer 3, eliminating one entire layer of processing.
- There is-no hope-by-hope flow control and error control. End-to-end flow control & error control, if they are employed at all, are the responsibility of a higher layer.