No cisco protocols will do byte substitution. I suspect it is a asynchronous protocol and you maybe able to get bstun protocol-group 1 async-genericworking.I thinl you were sent the web pages for this previous.ThanksDennis

I looked Wenco Mining telemetry on the web and couldn't figure out what type it is. Can you find out what encapsulation they use - async, bisync or hdlc/sdlc?ThanksDennis

If the frames are delimited by flag characters - x'7e' then stun basic could be used. If they are delimited by syns x'32' then it might be possible to use bstun. If it is asyn and there is a known startign and ending character then it is possible to ...

What kind of circuit is he trying to bring up.Note the source and destination address's. The destiantion is all fff's. The source is 8020.00d7.91b3Can you find this address anywhere? Does the topology have a loop by chance? ThanksDennis

If there duplicate mac is on a different lan then no problem. If it is on the same problem, then filter or put a hop count filter in it. Without the topology it is very hard to figure out solution.Dennis