Home Headset Installation FAQ Cisco IP phone wireless headsets and Electronic Hook-switch Cables (EHS)

Cisco IP phone wireless headsets and Electronic Hook-switch Cables (EHS)


Cisco brand desk phones are some of the most popular desk phones around. They are strictly used in a company setting and are not sold on the open market so technical information about them is limited. For example some of the 7900 series desk phones have a G at the end of it, unless you had asked a Cisco engineer you have no way of figuring out that the G means both that it is a newer model and that it had new graphical icons on the buttons (Hence the G).

I have complied some information on the Cisco 7900 series desk phones that I believe will be useful when figuring out if it is EHS compatible or not.

Essentially there is no difference between the Cisco 7900 series which have a G and those that do not. The important thing to take into account when figuring out if an EHS cable will work on your Cisco 7900 series phone is the firmware that the Cisco server is running through the Cisco CallManager.

The version must be 4.1(3) SR5x or higher, in order to verify this information one can do this by either asking your companies tech support or by logging onto the CallManager with a browser then press the detail button the main page to display the SW (Software) version.

The Cisco phone must be running firmware 8.3(3)x or higher. To find this out, press the settings button on the phone (Checkbox icon). Select “model information.” The firmware revision is listed under “Load File.”

I recommend talking with your IT professional before do anything with the firmware since it is extremely dangerous to mess around with.

Connecting your EHS cable:

The phone must be set so that it knows you are trying to use the EHS cable:

Step 1) Press the settings button on the phone (the checkbox icon). Select ‘Device Configuration’ > ‘Media Configuration.’

Step 2) If ‘Headset Enabled’ is ‘No’ and/or ‘Headset Hookswitch Control’ is ‘Disabled,’ contact your telephone administrator.


If for whatever reason the EHS cables do not work below is some trouble shooting advice.

Trouble Shooting:

Sometimes, once the cables are installed and the phone is programmed, you usually have to power cycle the EHS cable.

Step 1) With the headset in the charging base, unplug the EHS from your charging base for approximately 10 seconds,

Step 2) Plug back in and make sure that it is plugged in all the way.


If that doesn’t work do the following

Step 1) Unplug the cable from the phone for 10 seconds,

Step 2) Plug it back in and make sure the cable with what is call the “fork” is pushed in all the way and that the pins aren’t bent in any way.

For more information contact Jeremy by either emailing at jeremy@headsetplus.com or by calling 1-877-999-3838