Adsl modem stalls after posting a file using http

I did do another test, I surfed to the same our website using a GPRS mobile phone. This caused the same problem, so Wavecom does not seem to be the problem.


I’m working on an Open-AT apllication which upload’s its logfile to a HTTP-server with a http Post. This uploading works fine, but there seems to be a problem which is related to the adsl-modem on the server-side.

Somehow the adsl-modem locks our server from the internet for 15 minutes after a file was posted. This might look server-side related, but it only (and almost every time) seems to happen when the file was posted using the wavecom modem. This is what happens in detail:

1)My OpenAT application connects to the internet
2)It opens Port 80 on the wanted webside for TCP
3)It sends a HTTP POST with the logfile attached
4)Appache reply’s with “HTTP 200 OK”, and some application specific data
5)Appache closes Port 80.
6)my application processes the data, then detach GPRS, and switches off

So far so good,

Now if I connect to our website from the inetnet in the next 1 or 2 minutes there will be no problem. But after that not only port 80, but also other ports become stealthy for about 15 minutes. Connecting to the same server over our internal network works without any porblems. The only way for me to shorten this 15 minutes is to reset the PPPoA connecting in our ADSL-modem. And during this 15 minutes we can still use the internet from inside.

I’m new in the world of GPRS, TCP and HTTP, and I really haven’t got a clue where to search any further, so if any recognizes this, or does understand what goes wrong please let me know.