

Plantronics APC-43 EHS Cable – Desk Phone to Wireless Headset Adapter
The APC-43 EHS (Electronic Hook Switch) cable is our dedicated interface solution for connecting Plantronics wireless headsets to Avaya desk phones. This adapter cable enables remote call control—answering, ending, and muting calls—directly from your headset up to 350 feet away from your desk phone, eliminating the need for a mechanical handset lifter.
Designed for busy professionals who rely on mobility during calls, the APC-43 delivers plug-and-play simplicity with compatible Avaya models. Once connected, you gain seamless hands-free operation without returning to your desk, letting you multitask across the office while staying connected to every incoming call.
What’s included with the APC-43

Compatibility & Phone System Requirements
The Plantronics APC-43 is engineered specifically for Avaya desk phone models equipped with an EHS port. Confirmed compatible models include Avaya 1608, 1616, 9608, 9611G, 9621G, 9641G, and 9650 series phones—verify your exact model number on the phone’s base label before ordering.
On the headset side, this cable pairs with our CS500 and Savi wireless headset families, including the CS540, W740, and W440 models. The cable does not work with DECT headsets from other manufacturers or with Plantronics corded headset models. If your desk phone lacks a dedicated EHS port, you’ll need a mechanical handset lifter accessory instead.

Installation & Setup Process
Setting up the APC-43 takes less than two minutes with no tools required. First, locate the EHS port on your Avaya phone—it’s typically a small modular jack on the phone’s rear or side panel, labeled ‘EHS’ or with a headset icon. Gently insert the cable’s phone-side connector until you hear a click.
Next, connect the opposite end of the cable to the AUX or headset port on your Plantronics wireless base station. Most CS and Savi bases feature a clearly marked port; consult your headset’s quick-start guide if you’re unsure. Once both connections are secure, power on your headset base and wear your headset—you should hear a connection tone.
Remote Call Control Features
Answer & End Calls from Anywhere
With the APC-43 installed, your headset’s multifunction button becomes your primary call interface. Press once to answer an incoming call, press again to end it—no need to return to your desk or touch the phone handset. This hands-free workflow is essential for professionals who handle high call volumes while managing tasks away from their desks.
Mute & Hold Functions
The mute button on compatible Plantronics headsets syncs with your Avaya phone’s mute state, so colleagues on the other end experience true silence when you mute. Hold functionality varies by headset model—most Savi series headsets support on-headset hold, while CS500 models may require you to press hold on the phone itself. Check your specific headset’s user guide for hold-button mapping.



Compatible Plantronics Wireless Headsets & Accessories
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Common Questions About the APC-43 Cable
No, the APC-43 is designed exclusively for Avaya desk phones with EHS ports. For Cisco phones, use the APA-23 cable; for Polycom models, use the APV-63. Each phone manufacturer uses a different EHS signaling protocol, so cross-brand compatibility isn’t possible with a single cable.
The APC-43 is intended only for Plantronics wireless headset bases in the CS500 and Savi series. Corded headsets plug directly into the phone’s handset port or headset jack and don’t require an EHS cable for call control.
The APC-43 interfaces with the physical desk phone hardware, not the network or softphone software. As long as your Avaya desk phone has a functioning EHS port and is powered on, the cable will provide remote call control regardless of your network configuration or whether you also use a softphone client.
Check the rear or side panel of your phone for a small modular jack labeled ‘EHS’ or marked with a headset icon. Common Avaya models with EHS include the 1608, 1616, 9608, 9611G, 9621G, 9641G, and 9650 series. If you only see a handset port and a headset port (typically labeled with a single headset icon), your phone likely requires a mechanical handset lifter instead.
No, the APC-43 is a passive cable with no batteries or power adapter. It draws the small amount of power it needs from the Avaya phone’s EHS port to transmit call-control signals between the phone and your wireless headset base.
The APC-43 connects one wireless headset base to one desk phone. If you need two users sharing a single phone line, you’ll need a separate wireless base and APC-43 cable for each user, or consider a multi-headset conferencing solution designed for shared-line scenarios.
Some Avaya phone firmware updates reset EHS settings to default. Access your phone’s settings menu under ‘Options’ > ‘Headset’ and re-enable ‘EHS’ or ‘Electronic Hook Switch’ mode. If you don’t have admin access, contact your IT department—they can push the setting remotely or verify that the firmware version is compatible with EHS accessories.





