The USG5360 is deployed at the network egress. Then intranet users report frequent QQ network disconnections (once every three minutes). However, access to Web pages are normal.
Because users do not encounter network disconnections when they access Web pages, the route is normal. Execute a ping command for a long time to check for packet loss. No packet is lost. The fault is not caused by a link problem.
QQ network disconnections occur at a fixed frequency, so the cause may be a short session aging time. Check the QQ session aging time. The value is 30. Change the value to 120. Observe the network for three hours, no QQ network disconnection occurs.
Link problems or session aging time.
The interval between packets of QQ-similar applications is quite long, longer than the session aging time. Therefore, you are advised to change the session aging time or to upgrade the firewall to a later version that processes QQ packets specially.