I have a number of remote machines that log UV data in the main cities and one situated above the Littleton tunnel in Christchurch.

I do appreciate that Vodafone doesn't support Linux as a host OS.

These remote machines establish a openvpn connection to a server at my work and send data as required.
The link is perpetually always up, I have set wvdial in Linux so that it doesn't idle timeout.

I'm having some problems with a vodem (Huawei E220) freezing after a couple of days operation.
It would seem that the only way to get the link working again is to cold reboot the machine (i.e remove power from the vodem).
Since these are remote unattended machines this is a problem.  Performing dirty tricks with a UPS come to mind...

Can anyone comment on the way in which I'm using these devices, ie Am I just asking for trouble doing it this way.

It's reasonably important that I can talk to these machines via SSH etc for admin reasons which is why I want to link to always be up.

Also - With the GPRS network I found that Vodafone doesn't seem to support LCP echo requests which consequently causes some issues with the ppp link, is this still the case with the 3G network?

Any thoughts very much appreciated.

Graeme