VoIP + Asus RT-AX86U + Grandstream HT801 + SIP ALG

[pt44]

My VoIP was working fine a few months ago, with the Grandstream HT801, Starlink, Andrews & Arnold service in the UK. However, over the weekend, I discovered that it's no longer working. There is no voice in either direction. You can call the phone and it rings, but the call is dead. Same in the other direction, I can call out on it, it rings the other phone, but when they pick up, the call is dead in both directions.

The only things that have changed - I've ditched starlink and now have 5G broadband with EE going through the Asus RT-AX86U router. With Asuswrt-Merlin firmware on it.

I spoke to Andrews & Arnold, the VoIP provider. They said I should turn off SIP ALG on the router. But there doesn't appear to be a setting for that. I've also read lots of conflicting information about SIP Passthrough. Some people suggesting that disabling that will disable SIP ALG, as A&A have suggested, but others saying that it SIP Passthrough should be enabled otherwise VoIP won't work.

This stuff is way above my pay grade. I'm having to google every single term someone mentions.

Can anyone suggest why my current setup isn't allowing voices to be heard in either direction. Any suggestions of things I should try. I turned off Enable UPnP in the WAN settings, as this was the first thing A&A support pages suggested. I currently have SIP Passthrough enabled - but it seems to make no difference if it is on or off.

HELP!

 

[bennor]

Welcome.
Are you running Asus-Merlin firmware on your router? If so which Asus-Merlin firmware version?
See the WAN > NAT Passthrough page. It has several "passthrough" settings that you may need to adjust (enable) due to Asus-Merlin firmware setting several of them to disable where as stock Asus firmware sets them to enable.

 

[KevTech]

The difference is these three are enabled on stock.

 

[pt44]

Yes, I'm running Asus-Merlin. I've tried turning SIP Passthrough off - and on. Seems to make no difference to the issue. These are my current settings.

 

[heysoundude]

you should reboot the router after making the changes to settings/configs.

 

[OzarkEdge]

My VoIP was working fine a few months ago, with the Grandstream HT801, Starlink, Andrews & Arnold service in the UK. However, over the weekend, I discovered that it's no longer working. There is no voice in either direction. You can call the phone and it rings, but the call is dead. Same in the other direction, I can call out on it, it rings the other phone, but when they pick up, the call is dead in both directions.

The only things that have changed - I've ditched starlink and now have 5G broadband with EE going through the Asus RT-AX86U router. With Asuswrt-Merlin firmware on it.

I spoke to Andrews & Arnold, the VoIP provider. They said I should turn off SIP ALG on the router. But there doesn't appear to be a setting for that. I've also read lots of conflicting information about SIP Passthrough. Some people suggesting that disabling that will disable SIP ALG, as A&A have suggested, but others saying that it SIP Passthrough should be enabled otherwise VoIP won't work.

This stuff is way above my pay grade. I'm having to google every single term someone mentions.

Can anyone suggest why my current setup isn't allowing voices to be heard in either direction. Any suggestions of things I should try. I turned off Enable UPnP in the WAN settings, as this was the first thing A&A support pages suggested. I currently have SIP Passthrough enabled - but it seems to make no difference if it is on or off.

HELP!

VoIP works fine on ASUS routers. I keep WAN\NAT Passthrough\SIP Passthrough disabled to prevent one-way audio... but that's a legacy avoid-SIP-ALG habit that may no longer be necessary... and is not your issue, imo.

5G cellular Internet service may not play nice with VoIP. This discussion suggests that your EE 5G issue (signaling 'yes'; media/audio 'no' both ways) is caused by using the EE 5G service. If your VoIP provider and ATA both support using the TLS protocol (encrypted TCP) for call encryption, you could try configuring both the provider SIP account and registering ATA (per their respective instructions) to use the TLS protocol instead of UDP/TCP. TLS call encryption may 'hide' your SIP traffic on EE's network and allow it to succeed... and will also secure your last-mile SIP communications between VoIP provider and ATA.

Otherwise, if EE Tech Support (a person that actually understands their issue) can not help, you may not get SIP call media working on EE 5G Internet service.

For reference:
TCP = Transmission Control Protocol (TCP)
TLS = Transmission Control Protocol (TCP) with Transport Layer Security (TLS for call signaling encryption) and Secure Real-time Transport Protocol (SRTP for call media encryption) for call encryption between VoIP provider and User Agent only

OE

 

[RMerlin]

I have it set to Disable with my own Grandstream HT802 (fairly similar model to yours).

In Asuswrt-Merlin, "Disable" means that SIP ALG will be disabled - which is what you want in general.