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February 7th, 2017

All About Headsets: Headsets Supported by Allworx IP Phones

Allworx Product News | VoIP Business Phone System | Tips from the Experts

Author’s Note: (June 2020) With the release of Allworx® Interact Softphone™, it’s a good time to make a few updates to this posting. Although the majority of this document deals with the headset options for Allworx® Verge™ IP Phones, Interact Softphone allows clients to use their Windows PC as a phone and has different headset compatibility requirements. That new information is now included in the post.

The Allworx Verge IP phones support both wired and wireless headsets. Furthermore, the Verge 9312 IP phone supports two types of wireless headsets: connections via Bluetooth devices and connections through the headset port which use wireless base stations.

The Allworx® Interact Softphone™ supports the use of both wired (preferably USB) and Bluetooth headsets that connect to the Windows device where the Interact Softphone application is installed.

Because of all the possible combinations, there are many headset configurations available. This technical note explains some of the headset differences and simplifies the headset configuration.


Headset Types

Allworx Verge Phones

Note: Headsets connect to Allworx phones as indicated in the user guides for the Allworx 92xx and Verge series IP phones. These documents are available on the Allworx website Resources page (


Corded Headsets

The simplest configuration is a corded headset, which connects directly into the headset port on the back of the Verge IP phone. The Verge IP phone detects the headset by sensing microphone bias current. Even in this simple case however, there are some issues to consider.

Not all phone manufacturers use the same wiring and audio levels for the headset port. Because of these differences, headset manufacturers sell adapters (cables, amplifiers, volume controls, etc.) to match the different wiring configurations. The easiest way to determine the right adapter to use is by referencing the compatibility guides published by the headset manufacturers. The compatibility guides for Plantronics and Jabra (including VXi) can be found at the following URLs:

Another way manufacturers manage the headset port compatibility issue is to connect the headset through the handset port. This is the only solution available for phones without a dedicated headset port. The headset manufacturer provides an adapter (such as the Plantronics AP15 or M22), which allows connecting both a headset and original handset through the handset port. A switch on the adapter enables users to toggle between the handset and headset. A major disadvantage of this approach is that the handset must be lifted from its cradle to go off hook. Since Allworx phones provide a dedicated headset port, this method should never be used unless all other options have failed.

Note: Always remember to enable headset sidetone in the Verge IP phone settings when a corded headset is connected to the headset port.


Wireless Headsets

Wireless headsets come in two varieties, connections via Bluetooth and connections through the headset port. This section focuses on the connections through the headset port to headsets with wireless base-stations. Because the headset connects through the headset port, in most ways these headsets behave just like corded headsets and usually do not require adapters. Most base-stations have manual switch settings for compatibility with phones from different manufacturers. It is best to refer to the headset manufacturer’s compatibility guides listed above for exactly which settings to use with the Allworx Verge 9312 IP phone.

Note: Always remember to disable headset sidetone in the phone settings when connecting a wireless headset to the headset port. The wireless headset provides the sidetone.


Electronic Hook Switch EHS

Some wireless headsets support EHS (Electronic Hook Switch) capability. The idea of EHS is to provide communication between the headset and the phone for call control. It is generally used with wireless headsets since it enables users to have some control over the phone even when the user is not near it.

Over time, the capabilities of EHS have changed to the point where the single term “EHS” is no longer sufficient to describe all variations of this technology.

The Handset Lifter

The predecessor to EHS is the “handset lifter”. The handset lifter physically lifts the phone handset off-hook when the user takes an action (usually a button press) on the headset. When pressing the button again, the handset lifter lowers the handset back into the cradle. Headsets with handset lifters must connect through the handset port on the phone as they are using the handset going off hook as the mechanism for call control.

Most handset lifters also include ring detection. Ring detection consists of a small microphone that detects when the phone is ringing and forwards the ringing signal to the headset. In this way the user of a wireless headset knows that the phone is ringing even when the user is not near it and can answer the phone by pressing the button to lift the handset from the cradle. Examples of handset lifters include the Plantronics HL10 and Jabra GN1000.

EHS is eliminating these cumbersome mechanical contraptions.

Types of EHS

In its most basic form, EHS uses the headset detection mechanism to transition into the off-hook state without lifting the handset and does not require a handset lifter. Allworx 92xx IP phones and Verge 93xx IP phones support this basic form of EHS. All Allworx IP phones detect the headset by sensing microphone bias current and go off hook when the headset is detected and on hook when the headset is disconnected. To toggle between these states, Allworx IP phone users press a button on the wireless headset.

Unfortunately, there is no way for the phone to send messages to the headset without something more sophisticated. Several manufacturers (of both phones and headsets) have developed proprietary solutions for sending signaling from the phone to the headset. There is no single standard, which makes it very difficult for consumers to determine which products are compatible with each other. The market is flooded with a variety of adapters to connect phone “X” to headset “Y”.

Some of these competing standards include:

  • PSB – Plantronics Serial Bus, used by Plantronics EHS capable headsets. Built into the Altigen IP 720. All other phones require an adapter.
  • IQ – Developed by Jabra, used by Jabra EHS capable headsets. Adapter required.
  • DHSG – Developed by Siemens.
  • RHL – Developed by GN. Stands for Remote Handset Lifter (RHL).
  • MSH – Developed by Alcatel Lucent.

Allworx EHS

Allworx Verge IP phones transmit signaling that is compatible with the Plantronics APD-80 adapter module. The APD-80 adapter module works with the Plantronics CS500 and Savi 700 Series headsets. The Verge IP phones support full bi-directional EHS with these headsets. Simply connect the phone to the headset using the APD-80 adapter, and then enable EHS in the phone settings. As mentioned earlier, always remember to disable headset sidetone in the phone settings when a wireless headset is connected to the headset port.

In addition to Plantronics, Allworx is working with Jabra and other manufacturers to offer full EHS capability with these headsets as well. This technical note will be updated as new solutions become available.

Bluetooth Wireless Headsets – Allworx Verge 9312 Only

Bluetooth headsets do not use a wireless base-station to connect to the Verge 9312 IP phone. Instead the Verge 9312 IP phone connects directly via the wireless radio built into the phone.

NOTE: The Verge 9304 and 9308 IP phone and the Allworx 92xx IP phone series do not directly support Bluetooth technology.

Bluetooth headsets offer several advantages such as:

  • There are no wiring compatibility issues since the connection is purely wireless.
  • Signaling between the phone and headset is handled by the Bluetooth protocols, so separate solutions for EHS are not required.

On the downside, Bluetooth is more susceptible to RF interference, especially in an environment with many other Bluetooth and/or WiFi devices. For this reason, wireless headsets using DECT technology are usually preferred in a busy office or call center environment.  For additional information on planning dense Bluetooth headset deployments in combination with WiFi, read the Plantronics white paper Wireless Voice in the Office Environment.

If necessary, the Verge 9312 IP phone can support both a Bluetooth headset and a 2nd headset via the headset port. The 2nd headset can be a corded headset or wireless headset via a wired base-station. In this case, the headset function button on the Verge 9312 IP phone will always control the Bluetooth headset. A programmable button must be assigned to control the 2nd headset.

Note: Some wireless headsets, such as the Plantronics Savi 700, have the ability to connect via the headset port AND via Bluetooth. The purpose is to allow using a single wireless headset with both the desk phone (via the headset port) and a cell phone (via Bluetooth). For this reason connect one of these headsets to the Allworx phone by the headset port only, and NOT via Bluetooth.

Bluetooth Handsfree

This topic is not exclusively headset related, but is included because it can be a source of additional confusion when trying to configure a headset solution.

In addition to supporting Bluetooth headsets, the Verge 9312 IP phone can act as a hands-free interface for a smart phone, similar to the Bluetooth hands-free function available in some cars. When connecting your Verge 9312 IP phone to your smart phone via Bluetooth, a programmable button is assigned as a “Bluetooth Hands-Free”. Use this programmable button to make and receive calls on your smart phone using the handset, speakerphone or headset of your Verge 9312 IP phone- without ever having to take the smart phone out of your purse or pocket!

In this way, your headset connected to the headset port on the phone (wireless or corded) can be used with either your Verge IP phone or your smart phone (through your Verge IP phone). See the illustrations below. Note that the headset cannot be a Bluetooth headset, because the Bluetooth connection is already used for the hands-free connection to the smart phone.

Example 1:


Example 2:



Allworx Interact Softphone

Interact Softphone allows users to place and receive calls using their Windows PC - without connection to an Allworx desk phone. As a consequence, wired (preferably USB) and Bluetooth headsets are connected to the PC itself as directed in that equipment’s documentation.

Allworx recommends that users follow the Microsoft recommendations for PC audio device hardware described on the following websites.

  • Microsoft-certified USB devices:

  • Microsoft-recommended Bluetooth and USB headsets:

Lucas Curtis

Lucas is a Principal Hardware Engineer at Allworx, focusing primarily on audio performance of Allworx products, including signal processing specifications and validation. As a hardware engineer, his responsibilities also include hardware specifications, printed circuit board design and test.

Connect with Lucas Curtis

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