Polycom doesnt generate ringtone on transfer


I have a setup of about 95 polycom phones setup in an office. The receptionist is using an IP650, the rest of the office is running off ip301’s and about 20 ip330’s.

When the receptionist transfers calls to an extension the calling party does not hear a ring tone. There is one split second of ringing that you hear but I think that is most likely the 650 generating that tone ( I could be mistaken, I am by no means a polycom phone expert. )

What makes this whole situation a bit weird is the fact that when I transfer using blind transfer ( unattended transfer ) the call proceeds and the caller hears a ringtone. What could be causing this and if you know what are the possible solutions?

Secondly as you saw I have about 95 phones. Will I be needing a sip gateway soon, and what are the consequences of not getting one?