We receive frequently tickets about calls being disconnected after 30 seconds or after a transfer. 

In this topic we would like to go deeper in this case and explain the cause of these disconnects. 


In most cases it turns out that SIP ALG is enabled in the local network. 

We have a simple application for Windows machines to run in the local network. 

This application will check if SIP ALG is disabled or enabled. 

For more information, please check the SIP Alg detector

Fragmented packages

If packages sent by Kwebbl are exceeding 1500 bytes, the packages will be sent fragmented.

We sent those packages fragmented to be able for networks and devices to receive those packages. 

Sometimes routers or firewalls are set to block fragmented packages, which can cause different issues. 

We would like to advise you to check the settings if fragmented packages are allowed.