V2136AX - VoIP Not working on incoming calls

My customer has Gamma SIP trunks set up on a Panasonic PBX which were working fine on a Vigor 2865AX.

However, I've just changed their router to a V2136AX, which runs on OS5.

Despite configuring the firewall and the open/forward ports on the new router, the same as the old router, outgoing calls are fine, but no incoming calls.

I swapped the old router back again and i/c calls are fine.

Has anyone else had this issue please?

Cheers,

Mike

So, after initially drawing a blank with DrayTek technical this morning, this afternoon, they have been back into touch to say that there is a known issue with the V2136AX.

They have sent be beta firmware version 5.4.0 RC3, which I'm very pleased to say has resolved my issue.

Hi Mikefl0,

I'm running a 2136AX with VoIP traffic configured through the firewall. I have no issues with incoming or outgoing VoIP traffic. I was just about to upgrade the firmware to 5.3.9. Can you confirm which firmware version you were having this issue with? My current firmware is 5.3.7.1

Thanks

John.

Hi John,
The router came loaded with V5.3.2.1.
However, before I started the config, I updated to the latest version available which is V5.3.8.
One of the first things the DrayTek asked was had I updated to the latest version.
So, I can't say if earlier versions contained this bug or not.
I can send you a copy of the beta firmware if you'd like it.
I hope that helps.
Cheers,
Mike

Morning Mike,

I've just been investigating this issue and can confirm that the firmware I'm using also exhibits this behaviour. I have a weird setup using two different VoIP providers. Most inbound traffic arrives on the Telappliant Red service (formerly Draytel), and all outbound calls go via Zen's Digital Voice service (1000 minutes/month free), so I hadn't noticed the lack of incoming calls on the Zen service, and no one reported it!

Any way, I have raised a ticket with Draytek and hope that they will supply me 5.4.0 RC3 - If not I'll take you up on your offer. 

Thanks for your help

John.

P.S. The Zen service uses port 5060 - Telappliant Red uses port 5065
 

Update:-

Draytek gave me a download link for 5.4.0 RC3 - downloaded and installed, and the problem is resolved without any configuration adjustments required!

John.