Lync and Automatic Off-Hook Dialing


There are times when you need a phone set up to automatically dial a number when the handset it picked up.  This may be a reception or kiosk phone, or this may be an emergency phone.  If you’re responding to a voice proposal, these emergency phones may have many names, “Point of Emergency”, “SOS”, “Point of Rescue”, “Area of Rescue”.  All they typically do is dial the emergency services number as soon as someone grabs the handset.

Lync Phone Edition does not support this feature at this time.  In the past with Lync it needed to be handled by using an analog phone and IP gateway to perform the off hook dialing.  However, with all the Lync qualified phones out there, it is now easily done and I thought I’d take a moment to write up a post on accomplishing this with a few common models.  For each model, we’ll configure the phone to automatically dial extension 1804 when the handset is picked up with no buttons pressed.  1804 could easily be 911, or 999 or whatever emergency number is in use in your area.

Note: If you’re reading this, and you have a better method, please let me know in the comments or on Twitter at @CAnthonyCaragol

Polycom VVX

There are many ways to provision a Polycom VVX phone, and you may prefer another way than presented, however in many situations these configurations are handled on a one-off basis so I’ve chosen to modify the config file directly from the web interface.   To do so, let’s log into the web interface of our VVX phone.  In the picture below I’m using the UC firmware with a VVX300, but this works with other versions of the firmware and other VVX phones such as the VVX500.  Navigate to Utilities -> Import & Export Configuration, select Web in the Export Configuration dropdown and click Export.


We’ve got two lines we’re going to add, call.autoOffHook.x.enabled and  Replace the “x” with the line number (with Lync usually 1) and insert into your downloaded config.  Below is an example of my modified configuration.  The 1804 you see is the number I wish to dial automatically.

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<!-- Application SIP Amazon 20-Aug-14 14:36 -->
<!-- Created 17-09-2014 17:40 -->

Save the configuration and import it back into the phone.


Your phone will reboot, and log back in.  Once back up, pick up the handset and it should be dialing.

snom UC edition

With snom, it’s a bit easier.  In this example, I’m running the SIP firmware.  You’ll need to enable “Administrator Mode” to see these settings.  Log into the web interface and navigate to Action URL Settings.  In the “On Offhook:” area, enter  Click Apply.  You should be able to lift the handset and hear it dialing right away.  In our example below, you can see that I’ve replaced number_to_dial with 1804 again.


There are often multiple ways to accomplish the same goal.  Another option with the snom is to go to Advanced -> Behavior and set the Auto Dial to “after 2 sec” and the Preselection Prefix to your number.  Click Apply and you’re good to go!

snom2 snom3

AudioCodes 420HD, 430HD, 440HD

AudioCodes again makes it easy.  In this example, I’m using an AudioCodes 440HD running the UC firmware, however this can also be done with other models as well.  Connect to the web interface and navigate to Voice Over IP -> Dialing.  Set the Activate parameted to Enable to see additional parameters.  No, set the timeout to 0 to have the number dialed immediately (or a short delay if you want to ensure the handset is near the caller’s ear before to remote end answers), and enter the number to dial.  Click the submit button and test!


If you have a different or easier method, or find a mistake, please let me know. Thank you for reading!

4 thoughts on “Lync and Automatic Off-Hook Dialing

  1. Pingback: NeWay Technologies – Weekly Newsletter #113 – September 18, 2014 | NeWay

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  3. Paul B

    That’s a really handy tip. I am really pleased to have found this and even more pleased that you have shared this with the community. Thanks Anthony!

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