Hello,
I changed Open Link Timeout (ID=1000) parameter to maximum value as recommended : 259200 seconds.
I changed Server Response Timeout (ID=1001) parameter to maximum value too : 300 minutes (5 minutes).
I want to keep link between Server and Device opened (several hours), I will try to be clear to explain my problem :

Firstly, I receive correctly IMEI packets then I send ACK, then I receive Data Array, and then I send Data Array ACK.
After that, I can send commands correctly without problem, but unfortunately, after 5 minutes (300 seconds) the socket becomes closed :(
Even if I send new command every 2 minutes, the socket becomes closed after 5 minutes (so impossible to send more than 2 or 3 commands).
I understand if after every command I got new 5 minutes timeout, so every 5 minutes I can send I new command to keep Link opened.
But in my case the link becomes closed after 5 minutes even if I send a new command every minute :

I hope you understand my problem and I hope you find me a solution with a clear answer :)
Thank you.