ssh ethernet tunnel performance problem

[Guennadi Liakhovetski]

Hi

(I'm not subscribed, please, cc)

I've got an ethernet level ssh tunnel to a remote system. That system is 
running a terminal server, so, that tunnel is the only connection, I've 
got. The terminal server is connected via a serial and an ethernet cable 
to a test board and is configured to bridge that ethernet connection to my 
tunnel. I can then trigger that test board to start a TFTP or NFS data 
transfer over the tunnel from my system. The whole should look like this:

[my client] --- <internet> --- [terminal] === <serial cable> === [test ]
                               [ server ] ----- <ethernet> ----- [board]

(whereas I don't know whether the terminal server actually has 2 ethernet 
interfaces or only 1. I think, it should really have 2 at least, because 
actually it's serving 8 test boards, I'll try to clarify its 
configuration and post an update)

This works in principle, and from a "geographically close" location also 
runs reasonably quickly. Whereas from my half-world distance I'm getting 
like 1.5kBps tftp and a bit more with NFS. The person, who's set up the 
server says, that he previously also had performance problems with an 
older Fedora distro, but with Fedora 18 it runs fast now. I've tried with 
Debian squeeze with a self-build 3.9.1 and (about 1-2 year old) Ubuntu 
both over my and a 3G connection - the speed remains the same. Any clues?

Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/