For VVX models,
https://blog.merrittcomm.com/2017/08/16/8-steps-to-enable-electronic-hook-
switch-control-with-polycom-telephones/
For SoundPoint IP models,
https://www.youtube.com/watch?v=Z3HUxpfAip8
!!! Special Note : In rare cases, the JABRA EHS you have set up may not be
retained after reboot due to the Server. You must change the override feature of
the PBX / Server. Ask your admin to change it !!!
!!! Phone must be running SIP application 3.0.2 or higher (Except
5.9.0 problematic version ) and BootROM 4.1.0 or later.
TS4. If you can not hear any sound even though above TS1 - TS3 is not
abnormal, there may be a problem in the Headset port of your Desk Phone.
The Headset port of your Desk phone may be broken.
Here is how to check for any fault of the headset port of your Desk Phone. The
picture below will help.
1) Unplug the HANDSET cord from the handset port on your DESK phone.
Connect this to the HANDSET port (far right) of the Base of headset.
2) Connect the supplied telephone cord to the empty HANDSET port of the
DESK phone on No. 1 above step. The other side connects to the middle
telephone port of the Base.