Navigating SIP ALG Issues
Matthew Atkinson
Last Update 10 bulan yang lalu
Some routers provide Session Initiation Protocol Application Layer Gateway (SIP ALG) functionality. The purpose of a SIP ALG is to assist in the traversal of SIP traffic through devices such as routers or firewalls. However this functionality often causes more issues than it is worth. It is often wise to disable this feature when running SIP through your router.
Issues that could be causes by a poorly implemented SIP ALG include:
- Unable to register a SIP Device
- Unable to connect calls
- No audio on calls
- One-way audio on calls
- Poor quality audio
If you are experiencing one of these issues and are unable to disable SIP ALG, you can attempt to bypass it through one of the below methods
How to bypass SIP ALG
Change the SIP Transport
Changing from UDP transport to TLS will bypass SIP ALG. This is because TLS feeds all connection and media traffic through an encrypted tunnel that effectively hides the traffic from the SIP ALG.
Change the SIP port
Since SIP ALG generally runs on UDP port 5060, using our alternative SIP port UDP 50600 will bypass it.