It all started with a teeny tiny virus. Many of us moved to quarantine in our houses. Thanks to technology many of us had our own VoIP phones which you can take home, plug it to the internet and BAM… you get your work calls right at home. For some it started to work fine and for some not really…

To put it in simple words, may internet provider (ISPs) block voice protocols from coming in and going out and this causes trouble: AUDIO ISSUES. Choppy audio, one way audio, delay in the conversations and many more. In most cases the culprit is SIP ALG. This feature needs to be turned off. Usually when you have an internet installation in the office, the technician will ask if you are using internet phone and turn it off on the modem or router. However, for home installations, they may assume that there is no VoIP phones and keep it on. The best way to figure out if you have this feature somewhere within your network is to use this link: . Download and run the exe file. If you get False, you have to find another evil-doer on your network. If True read along…

This message shows when the SIP ALG is on.

First and easiest thing to do is to call your internet provider. You need to explain that you are using Voice over IP Phones and need them to turn SIP ALG off. They may say yes we can or no we can’t.

“Yes we can” is the best answer.

Example: Spectrum normally does this.

“No we Can’t, BUT”: get the Brand and model of your modem and google: Brand Model SIP ALG. You may find that this Brand Model has SIP ALG built-in; so there is no way to turn it off. However, most of the times this happens with older modems. So if you ISP is giving you free modem, ask for a replacement with a current product.

Example: FIOS-G1100 is something that will give you trouble if you have Verizon service, ask for replacement with NVG468MQ.

“No we Can’t, Period”: Just get a router online and cut the trouble.

Example: Me. I have Xfinity services here is Northern California. I bought my own modem to avoid paying extra monthly equipment fee. My VoIP phone worked perfectly for a month. After a month I had dropped calls, choppy audio, and one way audio. I used my SIP ALG detector and it was true. When the Xfinity technician installed our circuit, he didn’t share the login information, so I had no way of getting into the modem/router and didn’t want to reset and get in trouble with my internet service. Here is what I did:

I bought my own router. When I connected the router to the modem, I had the opportunity to login to the router and control SIP ALG.

Here are a few recommendations. after you do the easy setup you can login to the router and go to advanced, NAT forwarding >> uncheck the enable SIP ALG.

I wrote this blog because I receive emails and calls on a daily basis with audio issue complaints. SIP ALG is number one cause in 99% of the cases. But if this didn’t answer your question you can write back to us at and tell us your story and see if we can help you.

Here is my recommended router and you can read reviews about it by clicking on it:

TP-Link AX3000 WiFi 6 Router
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