No Audio or One Way Audio after Transfer or Forwarding on IPhone,CUCM,PSTN

[ossniper]

I am new to Cisco Collaboration and settin up IP Phones.

Incoming call from PSTN(Yeaster200). When i click the transfer button on the IP phone for the incoming call, call is transferred and picked on phone B, it would have the one-way audio or no audio on both sides for the caller and the transfer target party.

1. The CUCM is running on demo license.
2. Is there a Config setting i missed on CUCM?

I will appreciate feedback and solutions..

Best Regards

Osman.

[Anthony Holloway]

Demo license is unimportant.

Is your SIP trunk from PSTN connected directly to your CUCM?  Can you illustrate the solution?

[ossniper]

I have attached a Network Topology Diagram.

I am using Yeastar 200 PSTN Device. 

Yes, Its configured with SIP. 

I can make internal calls and forward calls within the office. 

External call from PSTN to Phone A, works fine and audio is audible, but once the call is transferred to phone B there will be no audio on both sides for the caller or receiver.

Thanks.

[Anthony Holloway]

I can't determine from your diagram if you have the SIP trunk connected to CUCM or to something else.  Are you familiar with Session Border Controllers?