Hi guys,
I have an issue causing client headaches and need some help.

Here's the setup:

HQ
1x PBX (Quada 2xi @ 192.168.1.253)
3x Phones @ 173.30.0.0/24 range
Network IP range 192.168.1.0/24
Vigor 2820vn
IPSEC VPN to the other 3 offices

Derby office
1x phone @ 192.168.10.11
Network IP range 192.168.10.0/24
Vigor 2820vn
IPSEC VPN from HQ

Directors home
1x phone @ 172.168.1.10
Network IP range 172.168.1.0/24
Vigor 2820vn
IPSEC VPN from HQ

I can only get voice 1 way from the Derby office to the HQ.

Things I have tried:
Disable SIP_ALG on all routers
Forwarded ports 5060 and 5004 to the PBX and phones in all sub offices
PBX into DMZ
Disabling all firewalls
Changing VPNs from IPSEC to PPP and back again
Changing all VPN ports from 5060 to 5070 (even though they are not used!)

Can you help??

Hi SpudR,

It's most likely a firewall/NAT issue on the Derby router causing the one way voice and that would be my first point of call to check that all settings are the same as the other 2 sites.

If my memory reserves me correctly, the 2820 reserves the SIP ports 5060 on the v models for internal/local use and although you are using a seperate PBX for your SIP, it is adviseable to change these to a different port to avoid any conflicts.

Second point of call would be the phone at derby, try using a STUN/Proxy setting for that phones SIP account (IP address of the PBX) to try and overcome any NAT issues.

So I tried everything I could think of and couldn't get this to work.
I replaced all the 2820VN with 2820N and lo and behold success!

Looks like the V bit was getting in the way and CANNOT be disabled..!

Grrr...

@DRAYTEK => Please give us the option to disable all the VOIP bits in this router...
(Though I'm not expecting a reply or any action from Draytek)

Hi

Just noticed the latest 2820Vn FW release notes claim it can now be disabled:

For VoIP
4. Resolved VoIP stability issues.
5. Improved Online Status for VoIP.
6. Corrected an issue where the fax relay did not receive all of the data from the caller.
7. Added a new telnet command to disable/enable VoIP service.

http://www.draytek.co.uk/support/download/readme_v2820.txt

Bri