Sangoma Connect - Allow Non-Encrypted Media not possible?

[dsubs (D rajan)]

I have a deskphone and sangoma connect on mobile.

The calling party is an external phone that is on UDP. Destination party is my deskphone and sangoma connect on mobile on TLS/SRTP.

Call does not ring Sangoma connect. However, it rings the deskphone. Cause given is user is busy (17), but could the real reason be that Sangoma connect does not allow Non-Encrypted Media when it is using TLS or Am I missing enabling some parameter setting?

PJSIP extension settings:
Transport: TLS
Media encryption: SRTP

Below are my observations:

1. Allow Non-Encrypted Media (Opportunistic SRTP) : yes

Calling from external UDP phone:
Rings deskphone, audio is fine
Does not ring sangoma connect mobile, call rejected.

From cellphone:
Rings deskphone, audio is fine
Rings sangoma connect mobile, but it disconnects immediately when answered

2. Allow Non-Encrypted Media (Opportunistic SRTP) : no
   Calling from external UDP phone:
   Rings deskphone, audio is fine
   Does not ring sangoma connect mobile, call rejected.

From cellphone:
Rings deskphone , audio is fine
Rings sangoma connect mobile, audio is fine

3. internal UDP extension to internal sangoma connect TLS extension works fine by calling internal ext number

4. It works fine if I call from an external TLS phone.

Thanks.