Thanks Brian. It now works better, but not fully (using 16659M).

 

What happens is:

• When one of the Polycoms seize the line it is ok - the other phone gets notification and the extension status is "in use".
• When one of the Polycom phones initiates a call - all is ok:
• The other side sees that the extension is in use.
• When it is put to hold all phones who share this extension see it and can pick the call.
•  When a call arrives, both ring; the one that did not answer gets only a cancel mesage without any further notification that the extension is in use by the other phone.

                         Thanks! __Yehavi: