Why Many Businesses Are Disabling Their SIP ALGsJuly 14, 2022
VoIP systems are usually very reliable. However, technical difficulties do occur from time to time. Many of these technical difficulties are caused by something called an ALG.
If you’re asking yourself, “What is SIP ALG?” you should know that SIP stands for “Session Initiation Protocol.” It is one of the cornerstone technologies of VoIP. ALG stands for “Application Layer Gateway.” This is a feature commonly found in routers that is intended to improve performance and add security. However, it can cause problems with some VoIP systems.
The Benefits of a SIP ALG
VoIP systems often use routers with ALGs to provide security. An active ALG can support a firewall. A properly functioning ALG can even improve connectivity. Unfortunately, even a properly functioning ALG can wreak havoc on a VoIP system.
VoIP Problems Caused by a SIP ALG
Most ALGs are beneficial for their users. This is why many routers have ALG enabled as a default setting. However, VoIP systems are the exception. The problems that an ALG can cause a VoIP system include:
- Calls accidentally being sent to voicemail
- Calls being dropped
- Phones not ringing
- Only one party can hear the other party
These problems can reduce the efficiency of a VoIP system or even render it unusable if the issue is bad enough. Thankfully, it is relatively easy to fix these issues. All you have to do is turn off your router’s ALG.
Disabling Your Router’s SIP ALG
Most business internet routers make it tricky to disable the ALG setting. This is because doing so could cause security issues. It is best to have your IT people disable the ALG so they can ensure your cybersecurity measures are still adequate. They may have to implement alternate cybersecurity measures after disabling the ALG.
You will likely need to be logged in as an admin to disable this setting. If you pull up your router’s settings, you will probably see the ALG option in either the “Advanced” or “Security” menus. Switch it off if it is causing problems with your VoIP system. Remember that some powerful firewalls may require port forwarding after an ALG is disabled. This is a little complicated to set up, so it is best left to IT specialists. If the ALG was causing problems with your VoIP system, the issues should cease immediately after you turn off ALG and reboot your router.