Bridge conference and one-way voice

Hi all,

 

Im new here in SBC world and need some help for conferencing bridge. i will ry to explain my issues.

 

I'm trying to create audio conference via cisco phone (this conference is hosted on core side)

So from this cisco phone A, i call cisco phone B (A and B are in call)

I push the button "conf" and call my Polycom C phone (A and C are in call, B is on hold)

I push again the "conf" button we are in conference but i cannot hear the Cisco B phones.

 

I do exactly the same scenario with 1 Cisco phone and 2 polycom