From: Dave McGuire <mcguire at neurotica.com> I'd do it with an HDLC/SDLC-capable chip like a Z8530...offload as much from the firmware as possible, leave those cycles for protocol handling. FWIW, I'm in the middle of writing a Z8530 driver for E11 (in heavily commented x86 code), which I'd be happy to contribute (after modifying as needed) if you aren't already neck-deep in SCC code. Wrapping the data in UDP is simple. The HDLC layer could deal with error detection/correction. Yes! Careful -- UDP doesn't guarantee in-order delivery. How does HDLC feel about little surprises? John Wilson D Bit