topic Re: Voip phone no audio in Internet

Voip phone no audio

alfee — Wed, 15 Apr 2026 20:11:42 GMT

Valerie modem suddenly blocking the audio of my voip phone. I'm using the exact same setting for almost 3 years, never an issue until now. Port forwarding was setup since day 1. Already reboot the modem multiple times. Still no audio. SIP-ALG is always off. Any idea what else I can do?

Re: Voip phone no audio

VirginPlusAntonie — Thu, 16 Apr 2026 16:39:47 GMT

Hey there @alfee ,

Welcome to the community and thanks for your question.

Virgin Plus Internet services now operate behind CGNAT (Carrier Grade NAT). This means Virgin Plus Internet subscriptions receive a private IPv4 address on the WAN, which is translated to a shared public IPv4 address for outbound internet traffic.

With this transition, IPv4 features that require inbound connections—such as port forwarding, DMZ and hosting services like Plex servers—will no longer function.

We understand this change may impact some Members’ existing network setups. We want to reassure all Virgin Plus Internet Members that standard internet connectivity and typical home usage will continue to work as expected with the default configuration.

Let the community know if you have more questions.

Re: Voip phone no audio

alfee — Thu, 16 Apr 2026 16:48:34 GMT

ok, then how can I get my voip phone to work?

Re: Voip phone no audio

mdon — Thu, 16 Apr 2026 19:55:44 GMT

Hi. Just wondering if you were ever able to get this resolved. After being away for the winter (with my Voip ATA) i came home to find out that i am having the same issue as you...no audio. Voip is so common these days that Virgin needs to have a fix ?

Re: Voip phone no audio

alfee — Thu, 16 Apr 2026 20:40:12 GMT

I got it working again.

On your Voip ATA setting. Try to use port 5080 instead of 5060. Make sure your voip provider support port 5080.

On the router/modem, port forward 10000-20000. leave it on Both.

you might also want to turn on DMZ on the modem for your voip ata.

Hope it works for you.

Re: Voip phone no audio

mdon — Thu, 16 Apr 2026 21:07:23 GMT

Thanks alfee

i tried changing the settings you suggested but it didnt work. the one thing i didnt check is to see if my voip provider (voip.ms) supports port 5080 but i have written to them to ask. Thanks again for your help. I have'nt heard anything from Virgin Internet yet

Re: Voip phone no audio

alfee — Fri, 17 Apr 2026 14:22:32 GMT

Hi mdon,

In addition to port forwarding and DMZ as mentioned before, is the SIP-ALG is off on the modem? please make sure is off.

Besides changed to port 5080, you might want to check the Registration refresh time, I set it to 120sec. I also use STUN server, you might want to check with your provider about the STUN server address and port#. my STUN refresh time set at 20sec and NAT refresh time at 20sec. Lastly, my Network Protocol is UDP only.

Hope this might help.

Re: Voip phone no audio

mdon — Fri, 17 Apr 2026 18:30:13 GMT

This message is for Virgin Internet support.

While i greatly appreciate Alfee's assistance with this problem, his solution did not work for me. Since Virgin made the change that changes the way my modem/router is working, i expect them to work with me......or work directly on my modem/router to create a solution that does work in my scenario.

Re: Voip phone no audio

VirginPlusKris — Sat, 18 Apr 2026 12:59:08 GMT

Good morning, @mdon. Thanks for reaching out, and thanks to @alfee for troubleshooting as well. 👍

You mention that Virgin Plus had made changes to how your system works; could you please share how you've confirmed this, and if so, what the changes were? Beyond that, had you taken the time and reviewed the suggestions from alfee in their last reply?

Confirming that SIP-ALG is disabled
Checking your registration refreshment time (alfee personally has it set to 120 sec)
If you use a STUN server, double check the address, port number, and refresh time
Check your NAT refresh time
Put your network to UDP only

If there's any further troubleshooting steps you've taken independently that you haven't shared with the Community, please do let us know. Also let us know what your VoIP provider has to say when they get back to you.

Looking forward to hearing back from you.

— Kris

Re: Voip phone no audio

mdon — Sat, 18 Apr 2026 17:13:24 GMT

Hi Kris,

Ive confirmed that Virgin Plus had made changes to how my system works by two things:

1) when i left to travel in November my VoIP was working just fine and i brought it with me. While i was away, i had my VoIP connected to my local internet modem and it worked fine there. When i brought it back home to Canada and connected the ATA to my home network, the audio was not working but my softphone was - but it is not connected to my virgin home internet (when it is through wifi it experiences the same audio issues). I then took my ATA device to a friends home, connected the ATA device to their home network (non-Virgin internet) and it worked. I had made no changes to my modem and i checked with my VoIP provider who told me they had made NO changes but:

2) while investigating this issue i checked out Virgin online support in which the Virgin representative wrote :

With this transition, IPv4 features that require inbound connections—such as port forwarding, DMZ and hosting services like Plex servers—will no longer function.

I have taken the time to try alfees suggestions but they did not work for me. Since Virgin created this issue i am hoping Virgin will also help solve it

Mike

Re: Voip phone no audio

VirginPlusKris — Sat, 18 Apr 2026 17:23:56 GMT

Thanks for your response, @mdon.

While the changes in regards to CGNAT are true, it is notable that it would seem @alfee's has seemingly continued to work regardless of this.

@alfee, would it be possible for you to share further details as to how you've set up VoIP on your end, and if you've had to make any changes in the past few months to accommodate for CGNAT? This would be helpful for mdon to be able to compare and contrast theirs to yours; if there's possibly a difference in set-up, or if there's a difference in what your respective VoIP providers may offer and provide.

Cheers.

— Kris

Re: Voip phone no audio

VirginPlusKris — Mon, 20 Apr 2026 12:49:07 GMT

Hi again, @mdon.

Just wanted to check in to see if you were still having issues with your VoIP audio; have you heard back from your provider on that end in regards to port 5080, or any further information that they were able to share?

If you were still in need of assistance, let us know and we'll be happy to take a closer look.

— Kris

Re: Voip phone no audio

alfee — Mon, 20 Apr 2026 14:39:06 GMT

I had the same setting for almost 3 years and never had any issue until 2 weeks ago. I'm very sure Virgin Plus changed something at that time. I already put my new setting on previous messages. Here is the recap:

On the Virgin Plus modem/router:

turn off SIP-ALG. Port Forward 10000-20000. leave it on Both. Turn on DMZ on the modem/router for your voip ata device. You should able to see your device on the list or you can enter the address manually.

On my Voip device, instead of using port 5060, I changed all of them to 5080. I ended up using UDP only. Registration refresh time, I set it to 120sec. I also use STUN server, you might want to check with your provider about the STUN server address and port# (you can also find some free public one online). My STUN refresh time set at 20sec and NAT refresh time at 20sec as well.

With these changes, everything works fine since last Thur.

Hope this might help.

Re: Voip phone no audio

mdon — Mon, 20 Apr 2026 16:14:46 GMT

Yes, i am still having issues with my Voip since Virgin made the change(s). I have had this configuration of Voip running for more than 10 years without issue. I did hear back from my VoIP vendor. Here is what they said : "Based on the information provided, since your ATA device works correctly on another network and your softphone also works when used outside your home connection, this indicates that the service and configuration are working as expected. The issue appears to be related to your home internet connection.

In this case, we recommend contacting your Internet Service Provider for further assistance. You may also mention that your connection may be affected by CGNAT (Carrier-Grade NAT), which can sometimes impact VoIP audio traffic and result in issues such as no audio or static during calls.

Your ISP will be able to review your connection setup and advise if a public IP address or other network adjustment is available.:

I have retried alfee solution but it does not work for me. Instead of using port 5080 (this time - i tried it before and it did not work) i just made sure that port forwarding included a wide port range.

End result....yes, i still need assistance to get around the changes that Virgin Internet made

Mike

Re: Voip phone no audio

VirginPlusKris — Mon, 27 Apr 2026 12:21:23 GMT

Thanks for getting back to us, @mdon.

Just to reiterate on what you said earlier in the thread while you were doing research - Virgin Plus home internet operates strictly behind CGNAT, and thus private IPs are exclusively assigned on WAN. This is not something that can be changed or exceptions provided to users.

With that said, we would still be happy to look further into it, especially considering VoIP services have continued to work for at least one other user in alfee. We'll be reaching out in a private message - Please check your Messages within your profile avatar in the top right corner.

Unsure how to check or send a private message? See How to send a private message

— Kris

Re: Voip phone no audio

Rdc1 — Wed, 29 Apr 2026 00:32:04 GMT

Hello Kris

Are you going to provide a solution for everyone to see please rather than private messaging one person?

This was a problem about 6 weeks ago and a modem reboot somehow resolved it at that time. Now it is back and a reboot is not resolving it.

Please let me know what virgin is going to do to unblock this issue and allow the traffic through?

Thanks in advance

Re: Voip phone no audio

VirginPlusKris — Wed, 29 Apr 2026 12:48:38 GMT

Good morning, @Rdc1. Thanks for reaching out.

Due to the nature of the issue requiring account and equipment specific insight and investigation, we're unable to provide a catch-all solution at the time of this post.

With that said, in the meantime we'll be happy to flag your account for further investigation. We'll be reaching out in a private message - Please check your Messages within your profile avatar in the top right corner.

Unsure how to check or send a private message? See How to send a private message

— Kris

Voip phone no audio

squidward — Sun, 03 May 2026 21:15:53 GMT

A few weeks ago I noticed whenever I call my voip line the calls are not going through ("temporarily offline or powered off") and I'd have to call twice or three times. I've since replaced my equipment with the voip provider and checked the connections. I turned off SIP ALG and I am still having the same issue. I'm using a cisco spa 112 adapter for the VoIP and the Virgin Valerie modem.

Re: Voip phone no audio

VirginPlusKris — Sun, 03 May 2026 21:23:13 GMT

Hi there, @squidward. Thanks for reaching out.

As with others earlier in the thread, we'll be happy to flag your account for further investigation. We'll be reaching out in a private message - Please check your Messages within your profile avatar in the top right corner.

Unsure how to check or send a private message? See How to send a private message

— Kris

Re: Voip phone no audio

bigguy — Mon, 04 May 2026 23:27:55 GMT

I have the same problem. The VoIP works for a week then doesn't. I tried port 5080 but still does not work properly. What is the solution?