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Need help going slow with 1720

Whilst I've read in many places that maintaining connections, e.g. an FTP connection, at a very low data rate is problematic, I havnt seen much in the way of solutions so perhaps someone can help.

The configuration I am using has a 1720 + WIC-2T connected by serial port to one PC and by ethernet to another. Configuration of the serial & ethernet interfaces went smoothly and pinging works in both directions through the router.

FTP works just fine with a source baud rate of 9600bps and above from the serial connection's PC (which is also the clock source), even with the router settings at a bandwidth of 5K and MTU 1500 on both the serial and fast ethernet interfaces. However when I drop the rate from the source to 4800, things start to get a bit unstable.

I'm finding that small transfers of under 1000 bytes work without problems however anything larger results in the connection being closed, looks like an input error and abort on the router.

Everything points to some sort of timing or acknowledgment issue.

Can anybody shed a little light on whether or not the router config can be tweaked to allow a more stable connection at a low source data rate.



Re: Need help going slow with 1720

I am not sure why this is happening, but just wondering if any of the 'debug ip tcp ...' commands can provide information about what is happening. I see quite a few 'ip tcp' related global configuration commands on the router. You can then look at the debug messages and see if tuning of any relavant parameters may be necessary.

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