Voice supports physical SIP desk phones using zero-touch provisioning. You register a phone once by its MAC address and assign it to an extension; the phone then downloads its own configuration — SIP credentials, server address, line keys — automatically when it boots. There's no need to type SIP settings into the phone by hand.
This article covers supported phones, registering a device, what happens on boot, configuring buttons, hot-desking, and troubleshooting a phone that won't register or won't pull its config.
Supported Phones
Voice generates provisioning configuration for the three major desk-phone families:
- Yealink
- Polycom
- Grandstream
Voice serves each vendor's native config format (Yealink .cfg, Polycom and Grandstream .xml), so any reasonably current model from these vendors that supports auto-provisioning from a provisioning URL will work. If you're unsure whether a specific model is supported, contact your MSP admin before purchasing.
How Zero-Touch Provisioning Works
When a supported phone powers on, it asks the provisioning server for its configuration file by MAC address. The server looks up the registered device, finds the extension it's assigned to, and returns a config containing that extension's SIP username, password, and server. The phone applies the config and registers — no manual setup on the phone itself.
The MAC address (a 12-character hardware ID) is printed on a label on the bottom of the phone and on its box.
Registering a Desk Phone
Registering a device is an admin task (owner or admin role).
- Go to Devices and register a new device.
- Give the device a label (required) so you can recognize it later (e.g. "Front Desk – Reception").
- Enter the phone's MAC address (from the label on the bottom of the phone).
- Select the phone's model / vendor so Voice serves the correct config format.
- Assign the device to an extension. The extension supplies the SIP credentials the phone will use.
- Save.
When you register a device, Voice generates its SIP credentials automatically. You don't enter or manage a SIP password yourself.
First Boot
After registering the phone:
- Make sure the phone is pointed at the Voice provisioning server. On a properly configured network this is delivered automatically (via DHCP option 66); otherwise the provisioning URL is entered into the phone's auto-provision settings once.
- Reboot the phone.
- On boot, the phone fetches its config, applies the SIP credentials for its assigned extension, and registers. Its status in Devices moves from provisioning to registered once it checks in, and you'll see its last-seen time update.
Configuring Line Keys / Buttons
You can lay out the programmable buttons on a phone (line keys, busy-lamp/BLF keys, speed dials) from the admin panel:
- Open the device in Devices and edit its button layout.
- Set each key's type, value, and label.
- Save, then push the configuration to the phone.
Pushing config (or issuing a reboot from the device's page) signals the phone that its settings have changed. The phone picks up the new layout on its next provisioning check and reloads — this is the standard "check-sync" behavior all three vendor families support. The same mechanism applies any change you make: button layout, reassigning the extension, or updated SIP credentials.
Hot-Desking
A desk phone can be shared between users with hot-desk login. An admin sets a hot-desk PIN on the device; a user then logs in at the phone to bind their own extension to it for a session, and logs out when done.
- Set the hot-desk PIN on the device in Devices (4–6 digits).
- A user logs in with their extension and PIN; the session lasts up to 12 hours before it expires automatically.
- Logging out unbinds the extension from the phone.
For security, hot-desk login is rate-limited: after several failed PIN attempts the phone is temporarily locked before more attempts are allowed.
Troubleshooting
The phone won't register / shows no line:
- Confirm the device's MAC address in Devices exactly matches the label on the phone (colons and dashes don't matter, but every character must be right).
- Confirm the device is assigned to an extension — a device with no extension gets a minimal config with no credentials and cannot register a line.
- Confirm the phone has network and internet connectivity.
The phone doesn't pull its config on reboot:
- Verify the provisioning URL is set on the phone (delivered by DHCP option 66, or entered manually in the phone's auto-provision settings).
- Make sure the vendor/model selected when you registered the device matches the actual phone, so it requests the right config file.
- Reboot the phone again, or use Reboot / Push Config on the device page to force a fresh fetch.
Changes I made aren't showing up on the phone:
- After editing buttons or reassigning the extension, use Push Config (or Reboot) on the device page. The phone applies changes on its next check, not instantly.
A phone is booting but I don't see it registered:
- An unregistered or mistyped MAC won't match any device, so the phone only receives a minimal "register-only" config. Unknown provisioning attempts are logged for admins; if you expected the phone to provision, double-check that its MAC is registered to a device and assigned to an extension.
FAQ
Which desk phones can I use? Yealink, Polycom, and Grandstream phones that support auto-provisioning. Check with your MSP admin about a specific model before buying.
Do I have to type SIP settings into the phone? No. Zero-touch provisioning delivers the SIP credentials and server automatically once the phone is registered by MAC and assigned to an extension.
How do I move a phone to a different user? Reassign the device to the new user's extension in Devices, then push config or reboot. The phone picks up the new credentials on its next check. For temporary sharing, use hot-desk login instead.
Where is the MAC address? On the label on the bottom of the phone, and on the original box.