When I connect via WinSCP (sftp) or putty (ssh) to the tablet I get a connection but after a few minutes the connection is lost and cannot reconnect by ssh / sftp, unless I disconnect and reconnect the wifi connection again. Then it works again normally - for a few minutes. The other way around, I can normally use internet from the tablet via the same router even when the computer cannot connect to the tablet.

This occurs with a Sitecom WL-114 router (always) and a Siemens SX-551 router (sometimes).

Pinging from the Windows machine results in this :

Pinging 192.168.2.2 with 32 bytes of data:
Reply from 192.168.2.4: Destination host unreachable.
Reply from 192.168.2.4: Destination host unreachable.
Reply from 192.168.2.4: Destination host unreachable.
Reply from 192.168.2.4: Destination host unreachable.

Ping statistics for 192.168.2.2:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),

The address ending in .4 is the Windows machine itself.

After dis- and reconnecting the tablet everything is OK for a few minutes.

Does anybody recognize this problem ?

My N800 used to go to sleep and be un-pingable unless I kept using the ssh connection (or did something on the tablet to wake it up, then the connection would magically work again, it's quite robust).

My N810 is much better and appears to always be available, without needing to be woken up, and yet the battery lasts longer too.

So to summarise, I've no idea, but I wonder if your lease gets dropped if the lease-holder is inactive for some amount of time?

What do you mean with 'lease' ? I issue a fixed IP address from the router to the N810.

ah, well ignore my point about the dhcp lease then.

I am having this issue as well using Transmit or Cyberduck. Once a connection is selected it is good one SFTP connection only. Whether it times out or if I close the sftp connection manually, I can only reconnect by deselecting and then reselecting the wireless connection on the tablet's menu.

I found this annoying aswell. It is to do with the TCP keep alive fuction I think.This avoids infinitely hanging sessions when one of the hosts fails.
You could try adding the line:-

ServerAliveInterval 180

Into the /etc/ssh/ssh_config file on the host computer

This will send out a little ping every 3 seconds and may keep the connection up during idle times. You need to be Root to add to the configuration file.

Just thought if you are using Winscp there is a keepalive function in the connections tab that you can set up to do this automatically :-)

I don't have a timing out issue. I would LOVE it if I could connect more then once per session though. Its not that big of a deal to disconnect and reconnect, but it seems it should work without having to do that. I'll ping the developers.

WiFi PSM

Thank you Ryan. It seems I do have some sort of timing aspect after all, but I have not tested enough to quantify it.