Sound clipping/delay over the phone


I’m running trixbox and freepbx 2.3.0rc 1.1 and i’m using the polycom’s 650’s. Now when i do a call from me to an outside line the call is clear and excellent and the same goes for incoming, now if i do ext to ext which is not accessing the trunk ( just staying on the pbx ) the call has clipping in it and there’s also a 1-2 second delay … does anyone have any suggestion’s ?

thanks for any and all input !!!