Support Knowledge Base

Online Resources
Warranty & Replacements
Search Knowledge Base

APC-4/APC-40/APC-41 (Cisco EHS Cable): How to Install

This procedure explains how to install the APC-4/APC-40/APC-41 EHS cable, which is compatible with the following Cisco phone models:

  • 7942G
  • 7945G
  • 7962G
  • 7965G
  • 7975G


Software Requirements

  • The Cisco server must be running Cisco CallManager System Version 4.1(3)SR5x or higher. Check with your telephone administrator to verify this.
  • The Cisco phone must be running firmware 8.3(3)x or higher. To find your firmware version, press the Settings button on the phone (the checkbox icon). Select "Model information." The firmware revision is listed under "Load File."

Phone Settings

The phone must have

  • "Headset Enabled" = Yes
  • "Headset Hookswitch Control" = Enabled.

To verify this:

  1. Press the Settings button on the phone (the checkbox icon). Select "Device Configuration" > "Media Configuration."
  2. If "Headset Enabled" is "No" and/or "Headset Hookswitch Control" is "Disabled," contact your telephone administrator.

Expansion Module Information

If the phone is equipped with a 7914, 7915, or 7916 expansion module:

  1. Plug the expansion module into the telephone AUX port.
  2. Plug the APC-4/APC-40/APC-41 into the expansion module.
  3. Use a Part Number 85638-01 (formerly 40287-05) adapter (sold through our distributors) to extend the APC-4/APC-40/APC-41 audio input to reach the headset jack on the phone. Click here to view the setup.

To Install the EHS Cable

  1. On your base, set your compatibility switch and speaking and listening volumes to the following:
    SettingCS50/CS55/CS70/CS70N/ CS351N/CS361N
    Cable APC-4
    CS500 Series
    Cable APC-40 or APC-41
    Savi Office/700 Series
    Cable APC-40 or APC-41
    Speaking VolumeB22
    Listening Volume233
     Image of SettingsImage of SettingsImage of Settings
  2. Connect your EHS cable to your phone as follows: