How to Disable SIP ALG on a NETGEAR Router


What is SIP ALG?


Ideally, most of the commercial routers consist of SIP ALG. It stands for Session Initiation Protocol Application Layer Gateway. Its function is to prevent the issues caused due to router firewalls. It does so by inspecting VoIP traffic and if found essential by modifying it.


How can it affect VoIP?


Although SIP ALG is expected to help clients who have telephones on private IP addresses, much of the time it is actualized ineffectively and causes a larger number of issues than it solves. Gradwell and different suppliers frequently find that the SIP ALG adjusts SIP parcels in unexpected ways, ruining them and making them indiscernible. This can give you unforeseen conduct, for example, telephones not enrolling and approaching calls fizzling.

Therefore if you are experiencing problems we recommend that you check your router settings and turn SIP ALG off if it is enabled.


Brief:

This article addresses how to disable SIP ALG on your NETGEAR device using the Genie interface. SIP ALG (Session Initiation Protocol Application Layer Gateway) is common in many commercial routers. It prevents some of the problems caused by the router firewall by inspecting VoIP traffic (packets) and if necessary modifying them. By default NETGEAR routers have SIP ALG turned ON.

Steps:

 

To disable SIP ALG on your NETGEAR device using the genie interface:

 

1. Connect to the NETGEAR device using a wired/wireless connection.


2. Once connected access the GUI interface of the NETGEAR device by typing http://www.routerlogin.net / 192.168.1.1 / 192.168.1.3 in the browser.


3. The router login screen will ask for a login and password. If you have not changed the password then the default username is admin and the password is the password.


4. Once logged into the NETGEAR genie page, click ADVANCED.

 



5. Click Setup.

 



6. Click WAN Setup.

 



7. On the WAN Setup page, disable SIP ALG by selecting Disable SIP ALG.

 



8. Click Apply to save the settings.

Disabling SIP ALG can help resolve many VoIP connectivity issues. If you continue to face problems after making this change, reach out to CallHippo support for further assistance.


Frequently asked questions:


Q: What role does SIP ALG play in VoIP communication?
A: SIP ALG is meant to help VoIP traffic pass through firewalls by modifying SIP packets, but it often causes more harm than good by interfering with VoIP communication.

Q: How can SIP ALG interfere with my VoIP service?
A: It can rewrite SIP packets in a way that disrupts phone registration, causes dropped calls, or leads to one-way audio where only one person can hear the other.

Q: Why does CallHippo recommend disabling SIP ALG for VoIP?
A: Because SIP ALG can corrupt or block VoIP traffic, disabling it ensures your phone system communicates directly and reliably with CallHippo's servers.

Q: What kind of VoIP problems are typically linked to SIP ALG?
A: Common issues include phones failing to register, calls not connecting, dropped incoming calls, or hearing only one side during conversations.

Q: My calls keep auto-dropping after being connected for a particular time (for example, multiple call drops after the 11th minute of being connected). Could this be related to my NETGEAR router?
A: Yes, if SIP ALG is enabled on your NETGEAR router, it could be interfering with your VoIP traffic and causing dropped calls. Disabling SIP ALG is recommended to resolve this.

Q: I can make outgoing calls, but I can’t receive any incoming calls—what’s going on?
A: This is a common symptom of SIP ALG interference. Disabling SIP ALG in your router’s WAN Setup settings can help restore full VoIP functionality.

Q: People can hear me, but I can’t hear them on VoIP calls. Is my internet the problem?
A: This one-way audio issue is often caused by SIP ALG modifying VoIP traffic. Turning off SIP ALG on your NETGEAR router usually resolves this.


I hope this helps. If you still face any queries, please feel free to reach out at [email protected]