Unable to transfer external calls, CME SIP!

[Imma]

Hello all,

I am experiencing problems with manual transfer of the external calls. 

For example, the external call first reaches the IVR, then regarding the number pressed by the user the call reaches one extension. After answering the call, press transfer button (either soft button on the screen or the transfer button on the phone keypad) and type the number you want to transfer the call. The external user is putted on hold (moh) but no transfer is made. 

Internal calls can be transferred easily. 

First I thought it was a matter of trans-codding- I changed the coded on the incoming dial-peer, and the phones like: 

voice class codec 99
codec preference 1 g711alaw
codec preference 2 g711ulaw
codec preference 3 g729r8
codec preference 4 g729br8

Also added:

allow-connections h323 to h323
allow-connections h323 to sip
allow-connections sip to h323
allow-connections sip to sip

But the problem still, persist.

Any idea why this may happen?

Thank you in advanced,

Denisa

[Brandon Buffin]

Under telephony-service check the transfer-pattern command. This command defines valid call transfer destinations.

Brandon

[Imma]

Hi Brandon,

Thank you for you reply.

I added the command transfer pattern under telephony-service:

transfer-system full-blind
transfer-pattern .T

but it didnt work.

external no. A -> call B , IVR is responded, user choose internal extension (206) -> 206 answered the call -> press transfer button, type the no. 207 he wants to transfer the call->receive the message: "the transfer cannot be completed"

External user listen all the time music.

We have two providers one for both incoming and outgoing and the other is only for incoming.

Interesting is the fact that with the first one the transfer works great (without adding transfer-pattern command).

But with the other provider the transfer does not work.

If you have any other idea, please share it,

Thank you in advance,

Regards,

Denisa

[Brandon Buffin]

If it works with one provider and not another that would suggest the problem is with the carrier. I would suggest a couple of things:

1. Run "debug ccsip messages" and make a test call.
2. Contact the carrier, make a test call and see if they can tell you why the call is not completing.

Brandon

[Imma · Accepted solution]

Hi Brandon,

thank you for your recommendation. 

The problem is resolved after I added the below command: 

voice service voip

no supplementary-service sip refer

It seems that the provider does not support the SIP REFER method, rather it use an INVITE to complete supplementary services such as call transfer.

Kind Regards,

Denisa

[Imma]

Hi Brandon,

thank you for your recommendation. 

The problem is resolved after I added the below command: 

voice service voip

no supplementary-service sip refer

It seems that the provider does not support the SIP REFER method, rather it use an INVITE to complete supplementary services such as call transfer.

Kind Regards,

Denisa