I have just purchase two VigorPhone 350s and planned to use them with my Vigor 2820vn. I have two Draytel accounts. VOIP has worked perfectly with analogue phones and the 2820vn.

Before configuring the phones, I upgraded the firmware on the Phones to 12202.26.1.03i and the 2820vn to 3.3.3.

Router Model: Vigor2820 Series Version: 3.3.3_232201 English
Profile version: 3.0.0 Status: 1 (0x49c73056)
Router IP: 192.168.1.1 Netmask: 255.255.255.0
Firmware Build Date/Time: Oct 23 2009 15:23:15
Revision: 16717 V333
ADSL Firmware Version: 232201_A Annex A

I removed the SIP accounts on the router and configured the phones. They managed to register with the server. I found at this point I could phone out but couldn’t hear the person on the other end and the other caller could not hear me. I could not phone in. When I phoned in, Draytel said the user was not available and connected to voicemail.

Advice on the Draytek forum said set Application Layer Gateway for NAT traversal via telnet. I did this and confirmed the ALG was set. This allowed me to dial in and the phones would ring. Now the other caller could hear me on the 350 but I could not hear them. Dialling out worked as well, but I could not hear them.

I changed the codec and tried every combination but found that many would result in the phone being unable to connect to Draytel.

I spent a full day trying to get them to work and in the end had to give up and plug the analogue phones back in. They are cracking phones so I would hate to have to send them back.

Anyone got any ideas?

I finally bit the bullet and decided to phone Draytek premium support.

The girl I spoke to was very helpful and managed to solve the problem.

The changes made were as follows:

In General SIP Settings >> Other Settings:

Set STUN Server: stun.xten.com
Set STUN Port: 3478

Save and reboot. It took a couple of minutes before it registered, but after that everything works as it should.

I was advised by premium support that there is an issue with the Vigor 2820vn when used with multiple VigorPhone 350s (or any IP phones).

With SYS_ALG set on, the router will not allow more than one phone connect to SIP accounts.

With SYS_ALG set to off, multiple phones will connect to the accounts and be able to phone out, but will not be able to receive any phone calls.

As far as the SIP accounts are concerned, the user is offline.

It also appears that the VigorPhone 350 when used with the 2820vn and Draytel accounts will only work if a stun server is used. There is no information anywhere about configuring the product to work with Draytek 2820vn or Draytel SIP accounts.

Having just purchased 2 x VigorPhone 350s, I am annoyed that I cannot use them with my 2820vn and that I had such a huge problem trying to configure them to work with the 2820vn and Draytel SIP accounts.