You are right Jggimi, I was not enough precise in my description.. It is lso because I have difficulties to identify the real cause. I will try to detail a bit more:
I talk about an https link that point on an OpenSource Application.
This appliction is based on:
CentOS, Appache2, Mysql, phpMysql, Perl.
Consider the DB server installed separatly of the www server.
That envirronnement is facing internet.
When connecting from anywhere on the net, the application (understand the web interface) do not hang. But when connecting from behind the OBSD box, it hang after few minutes... I did tryed to sniff on one of the machines connecting from behind the box and I can see many bad TCP (TCP retransmission, TCP Dup Ack).
Usually it is at those steps that the page start to hang. From outside (means anywhere on the net) I noticed the same bad TCP, but it does not hang.
If I disable pf, the app work fine....
From behind the box any access to internet web sites is good.
Hope I was clearer here.. Thanx