Cisco phones has two different type call management systems – CUCM and CUCME.  Either You or your in house IT person can perform the following steps to setup an Plantronics APC-42 (formerly APC-41) EHS with a Cisco phone models: 7942G, 7945G, 7962G, 7965G, 7975G, 7821, 7841, 7861 (If your Cisco phone is not, listed, it’s NOT EHS compatible, you must use a HL10 lifter).  (Make sure the CUCM version is 4.1(3)SR5x or higher. FirmWare is 8.3(3)x or higher)

For Cisco CUCM – Cisco Unified Communications Manager:  (Make sure the CUCM version is 4.1(3)SR5x or higher. FirmWare is 8.3(3)x or higher)

• Access the server administrator with a browser (i.e. Internet Explorer or FireFox)
  1. Select Device > Phone through the drop down menus. 
  2. Click “Find” with no selection criteria to obtain a list of all phones
  3. Open the desired phone.  Scroll down to “Wireless Headset Hookswitch Control”, set to “Enabled”, Click “Apply”.
  4. Reset the phone.

For Cisco CUCME – Cisco Unified Communications Manager Express:  (Make sure the the phone FirmWare is 8.3(3)x or higher)

• Access to CUCME via the router’s command line interface and use the following commands to enable EHS feature for the phone.
  1. Device-Name (config)# telephony-service
  2. Device-Name (config-telephony)# service phone ehookEnable 1
  3. Device-Name (config-telephony)# create cnf-files
  4. Reset the phone