Early Media Video Issues with 2N and Yealink T58W Pro

[CITMark]

Hello all.

We have a 2N IP style that we are trying to use as a video intercom ringing to (for the sake of this testing) a single Yealink T58W Pro.

I am unable to get the preview video stream to show up on the Yealink from the 2N's camera when the 2N calls the Yealink. When I accept the call on the Yealink, the video feed pops up immediately.

I am able to get the preview to work via a direct SIP call from the 2N to the Yealink which bypasses the 3CX server (up to date V20 hosted in Amazon Lightsail in our instance).

This leads me to believe that the issue is either in the PBX or in NAT, although I am not sure which.

I do have the ENABLEEARLYMEDIA set to 1, which it is by default, but I am truthfully unsure if 3CX can even support early media video previews as I am finding conflicting answers on the forums and online.

Thank you for any help in advance!

 

[KyriacosS_3CX]

Hello,

Early Media is not supported in extension-to-extension calls. On external (trunk) calls it is. Once an internal call is answered then the video plays if the devices have compatible codecs.

On receiving devices, setting auto-answer for the doorphone extension can be an option.

 

[JohnS_3CX]

@CITMark I can suggest an alternative if you have any Fanvil phones (ie. Fanvil V65).

They use a clever trick that does not rely on 183: Under Line > SIP > Advanced you enable preview, and set to 2XX.



1. Your phone rings and you see the video too, but in reality it already answered the call in the background.
2. On your screen it still shows a ringing state, and the visitor still hears a progress tone, which the Fanvil is generating for them.
3. If you want to speak to them, you answer the Fanvil, and you can talk to the visitor.

Since the call is always answered in the background, there is no 183 to worry about.
This works on 1:1 calls, not for Ring Groups or Queues.

 

[CITMark]

Hello,

Early Media is not supported in extension-to-extension calls. On external (trunk) calls it is. Once an internal call is answered then the video plays if the devices have compatible codecs.

On receiving devices, setting auto-answer for the doorphone extension can be an option.

Understood, thank you for the clear explanation. I will test the feature with external calls and see if I can get that to work. Do you know if there is a technical limitation as to why internal calls don't support early media, and is that something that could be added in future updates?

 

[CITMark]

@CITMark I can suggest an alternative if you have any Fanvil phones (ie. Fanvil V65).

They use a clever trick that does not rely on 183: Under Line > SIP > Advanced you enable preview, and set to 2XX.

View attachment 50752

1. Your phone rings and you see the video too, but in reality it already answered the call in the background.
2. On your screen it still shows a ringing state, and the visitor still hears a progress tone, which the Fanvil is generating for them.
3. If you want to speak to them, you answer the Fanvil, and you can talk to the visitor.

Since the call is always answered in the background, there is no 183 to worry about.
This works on 1:1 calls, not for Ring Groups or Queues.

That is an interesting work around! I will certainly look into this. Thank you for the suggestion.