We just configured Polycom 650 with sidecar and it worked fine. One thing we have to change in provision template for Polycom 650 template
<reg
reg.1.address="%%extension_number%%"
reg.1.auth.password="%%extension_auth_pw%%"
reg.1.auth.userId="%%extension_auth_id%%"
reg.1.displayName="%%extension_first_name%% %%extension_last_name%%"
reg.1.lineKeys="1"
reg.1.lineKeys.SPIP320="2"
reg.1.lineKeys.SPIP321="2"
reg.1.lineKeys.SPIP330="2"
reg.1.lineKeys.SPIP331="2"
reg.1.lineKeys.SPIP335="2"
reg.1.lineKeys.SPIP450="1"
reg.1.lineKeys.SPIP550="2"
reg.1.lineKeys.SPIP560="2"
reg.1.lineKeys.SPIP650="2" <<<<<<Default is 2, and we change to 5 for reception able to get 5 incoming call on hold
reg.1.lineKeys.SPIP670="2"
This video showed how to change how many extension that you want for 650 model, I didn't used this but my teammate think this will help you also.
http://www.youtube.com/watch?v=xIUEwfcuxPM
Let us know if it help
