johan johansson

I've been trying to figure out what's supposed to happen to a (windows
mobile 2003-based) device that goes into standby. It's become popular to
configure these so that the GPRS is "always on", thus making a
connection survive standby. This always struck me as rather pointless
since "the CPU will stop anyway".

I did some experiments today and here's what I found (on a particular
device).

I ran a ping *from* the device to a laptop and sniffed the traffic with
Ethereal. When I pressed the power button, what one would expect to
happen happened: the pings stopped instantly. After a while I started a
ping going in the other direction, i.e. *to* the device. Not only did
this provoke a response, but the original pings from the device resumed,
but the screen did not turn on. When I stopped pinging the device, the
pings *from* the device stopped after a few seconds.

Are there rules laid down for this by Windows CE and if so are they
do***ented somewhere?

Thanks,
Johan