Solved outgoing call: being put on hold

[dan-bln]

Similar Issue as described in here - unfortunately no resolution had been documented back then.

Not familiar with a distinct change on my end of the 3CX PBX. Tried various settings, without resolution.

Problem:

• Dialling an External Number . (different cell phone numbers) internal party is placed on hold while external party's phone is ringing. On Pick up no sounds / dead line.
• after called party picks up, after a small timeout, both ends are disconnected.
• the defined movile number is also entered as the Mobile# of the extension at question.

Calling another Mobile number, rings normally.

 

[leejor]

internal party is placed on hold while external party's phone is ringing. On Pick up no sounds / dead line.

To be clear...you dial a number, then while it is ringing, you place the call on hold?? I first of all, question why anyone would do this, when the called party could answer at any time

How it the hold done...dial code, hold button? What type of set(s) is this happening to? Does this happen only when calling a mobile number, or landlines as well? All over the same provider, or do you have a second provider to test over?

Did this just begins after an upgrade, or some other change?

 

[JohnS_3CX]

Have you ran a capture yet to see the call flow in wireshark?

 

[dan-bln]

John, sure, PCAP file is accessible thru my drive:

- where may I provide you with the PCAP File? Neither URL sharing nor upload worked here.

I traced the mobile connection 0171 area code , another going to voicemail but working (0176 area code) and a disconnect on connect to an 800 number.

 

[JohnS_3CX]

Hi Dan,

Do not post PCAP here because it will contain your private information which should not be made publicly available.

 

[JohnS_3CX]

Dan do you have SRTP enabled in your Trunk under the options tab?

 

[dan-bln]

Dan do you have SRTP enabled in your Trunk under the options tab?

Yes, I do.

Turning SRTP off seems to have resolved the issue.
Thanks.

 

[JohnS_3CX]

Glad it helped!

It seems your provider does not respond correctly when you have SRTP enabled.

3CX will send a non encrypted SDP and a Secure SDP and the provider responds back with

1.) a non-secured SDP (they probably don't support this feature)
2.) does not include their Connection IP (hence nowhere to send audio, hence silence)

Session Description Protocol
    Session Description Protocol Version (v): 0
    Connection Information (c): IN IP4 0.0.0.0

The reason you heard music on hold was probably because you dialed using a client in CTI mode which performs a MakeCall fucntion: The PBX calls your phone and puts it on hold, tries to reach the other side, and when successful takes you off hold and connects you to the other party

 

[dan-bln]

Thanks and much appreciate the explanation. Very helpful.

 

[JohnS_3CX]

You're welcome, glad things were resolved