Frequently Asked Question

Some VOIP video telephones like those from Grandstream are partially supported (Early video will be broken when in standard mode, phones require answer before dialing group to allow Asterisk to control the early media instead of a door intercom video source. While this works it has one side-affect, with some door intercoms the ringing stops and you will hear dead air until someone answers. (Often seen with 2N). This can be mitigated by playing a background message through the 2N while devices are ringing.

Non-Video phones partially supported (Early video broken when in standard mode depending on VOIP phone ignoring video invite and not creating a re-invite with audio only. Phones that do this break all video to all devices including Crestron panels. Options limited to sequential dialing or using a secondary AVLinkPro SIP PBX to act as a B2BUA (Back to Back User Agent). Only way to know if a VOIP phone will work correctly is to send a unit to us so it can get tested in the LAB. Please keep in mind that manufacturers of these phones changed firmware all the time and while a phone may work today, a year from now updated firmware may break things. Grandstream is a good example of this, a year ago their phones worked perfectly but a firmware update broke them. Some manufactures are very responsive to fixing firmware bugs like Fanvil, other are not.

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Note: Testing with video on Crestron panels and phones. Best to test all Crestron panels first and make sure preview video works, then add one video VOIP phone into the dial group at a time. Test and if preview video works then move onto the next phone.

One video VOIP phones not properly configured for preview video will cause all devices to have no preview video.