Ever had a videoconference drop after a consistent amount of time (i.e. 15 or 20 minutes) all the time? I have two districts struggling with this problem right now.
How do YOU troubleshoot a time out problem?
Here’s what I do. Remember that I’m not a network person! I don’t know exactly how to fix the router or firewall settings. But I can help our district network techs know what to look for!
Check the Settings on the Endpoint
First, almost all videoconference systems have a maximum time in call setting.
On the Polycom VSX 7000, it’s under System, Admin Settings, General Settings, System Settings, Call Settings, Maximum Time in a Call. I usually set this as high as it can go.
Check the Settings on Firewalls & Routers
Next, if that didn’t fix it, I talk to the network techs and give them some ideas of what to look for.
Since I really have no idea how to change settings on a firewall or router, I can really only explain what happens during the videoconference call.
- The call is set up on port 1720. The two codecs do a caps exchange (capability exchange) and negotiate the media ports to use during the videoconference. (If a gatekeeper is involved in the connect, ports 1718 and 1719 may be used also.)
- Then after the call is set up, the traffic switches over to the ports that are used for the media traffic. We usually have our Polycom VSX 7000s set to “fixed ports” which means it should be communicating in the range of TCP 3230-3235 and UDP 3230 to 3253. You can find a fairly comprehensive list of ports used in VCs here.
Sometimes if the router or firewall isn’t seeing any traffic, it may close the ports thinking that the call has ended when really it hasn’t.
This info usually helps my techs enough to figure it out from there.
What about you?
Have you ever run into a problem with videoconferences ending after a specific amount of time consistently? How did you solve it?
Filed under: Techie Stuff