Tandberg 1700 connection issue

[gap15]

Hello,

I have a Tandberg 1700 unit in my homeoffice and I would like to use to do video calls with business partners and colleagues. When I call a public or private IP test string for example 66.244.181.76, I get connected (it says "connected") but I only see a black screen. NO VIDEO, NO AUDIO.

I operate the Tandberg 1700 beyhind a standard cable modem/router. Is this an issue with pre-set firewall settings or with the setup of my unit?

Thanks a lot for any helpful advice.

[Anthony T · Accepted solution]

Two potential problems, both related to your cable modem/router/firewall.

I'm guessing that your 1700MXP is not registering to a gatekeeper-type device (like a VCS) anywhere, and calls are going point-to-point only, with direct IP calling.

This suggests that you have not configured the NAT settings on the 1700MXP.  The H.323 protocol embeds the unit's IP address in the payload of the call stream.  If that IP address is a different, local IP address (192.168.x.x, 10.x.x.x or 172.16.x.x usually) than what the publicly addressable IP address is, then the return media streams end up not going to the right place.

This can usually be resolved by going to Network > LAN Settings > H.323 Settings > Adv. H.323 Settings, and setting NAT to ON, and NAT Address to the external publicly addressable IP address of your modem/firewall/router.  You will also need to configure port forwarding on your modem for the following ports to point to the private address of the 1700MXP.

Port 1720/tcp
Port 5555-5574/tcp
Port 2326-2485/udp

If you or your organization have a public gatekeeper you could register to, then this would be unnecessary, thanks to the gatekeeper and the Assent protocol built in to the unit.

Otherwise, if your unit is registering to a gatekeeper, or has a publicly reachable IP address already, it suggests you only have some ports to open up on your modem/router.

[gap15]

Thanks a lot. I followed the guidance and the system is working perfectly now.

[Wayne DeNardi · Accepted solution]

Firstly, I should point out that the 1700 MXP is past it's End of Support date of 28 February 2017, so it's no longer a supported device, nor will it get any security updates or patches if you do decide to keep using such an old device.

But, to try to help with your issue, the cause of 99% of one-way (no none) video or audio issues is the firewall / NAT configuration.

Make sure that you have your MXP correctly configured for NAT (see the System Configuration > H.323 page of the web interface), and fixed ports.  Then check that you have all the required ports open on your firewall 

The ports required for an MXP endpoint using H323 are:

H323/RAS   : 1719 UDP
H323/Q931  : 1720 TCP
H.245      : 5555 - 6555 TCP          
Media      : 2326 - 2487 UDP