Have you checked that there is a signal being sent even when there is
no network traffic? e.g. Watchguard systems have a VPN Keep Alive
setting that sends a ping to the host once a minute to keep the tunnel
open.

I don't think its a Firebird issue but am prepared to be proved wrong.

Do you lose connection if you only have e.g a spreadsheet or a word
document open, forgetting the database - you don't say if that is ok
or not.

If all else fails you could create a trigger to run a select single
value from a single-row table, based on system time. This is not the
way to solve the problem long-term but may help to placate your
customer temporarily.

--
Alan J Davies
Aldis


Quoting Paul Hope <paulhope@...>:

> Hello
>
> Win2K and XP clients remote to FB 1.5 on Win server 2003.
>
> We connect remotely to customers using either a VPN or a route set up in our
> ADSL router. We just use a TCP/IP connection on port 3050. With most of
> the customers we can work at our leisure using our app or using IBExpert
> without problem. However with one customer if we are inactive for more than
> about 5 minutes the database connection is lost. We have been to trying to
> solve this with their technical support people for some time but have
> failed.
> Now a second customer has installed new equipment and the same thing is
> happening there, while it worked fine before they made the change. Their
> support guys tell me they dont think there are any relevant settings in the
> firewall, router, server etc.
>
> What are the issues we should look at?
>
> Regards
> Paul
>
>
> [Non-text portions of this message have been removed]
>
>