# Control an Incompatible IP Phone by Cloud Voice App Web Client

CTI (Computer Telephony Integration) mode lets the Cloud Voice App Web Client take command of a physical IP phone (a desk phone that connects over the internet) registered to your extension. Once the two are linked, you place, answer, and manage calls from the web client's on-screen controls, while the audio and the actual call handling stay on the desk phone.

:::note
Think of the web client as a remote control and the desk phone as the speaker and microphone. You click the buttons on screen, but you still talk and listen through the physical phone. This is useful when you want mouse-and-keyboard call control without giving up your desk phone's handset.
:::

## When to use this

Follow these steps when your desk phone is **not** one of the models that support native CTI control. If your phone is on the supported list, it already works with CTI directly and you do not need this workaround.

To confirm whether your device qualifies for native CTI, check the compatibility lists:

- [Compatible Yealink IP phones](/pbx/web-client-user-guide/cloud-voice-app-web-client-cti-overview/#linkus-web-client-cti__compatible-yealink)
- [Compatible Fanvil IP phones](/pbx/web-client-user-guide/cloud-voice-app-web-client-cti-overview/#linkus-web-client-cti__compatible-fanvil)
- [Compatible Snom IP phones](/pbx/web-client-user-guide/cloud-voice-app-web-client-cti-overview/#linkus-web-client-cti__compatible-snom)
- [Compatible Grandstream IP phones](/pbx/web-client-user-guide/cloud-voice-app-web-client-cti-overview/#linkus-web-client-cti__table_cqw_gs3_5dc)

:::tip
Only phones outside the compatible lists need this procedure. If your model appears in one of the lists above, use its native CTI support instead: it is the simpler, better-supported path.
:::

## Link the phone in CTI mode

1. Verify that the extension registered on the IP phone is the same extension you are signed in with on the Cloud Voice App Web Client.
2. Put the web client into CTI mode:
   a. Sign in to the Cloud Voice App Web Client.
   b. In the top-right corner, click the CTI icon ![CTI mode toggle](/images/pbx/cti.png), then choose your IP phone from the drop-down list.

:::caution
The extension on the desk phone and the extension signed in on the web client must be the identical extension. If they do not match, the phone will not appear as a controllable device (or the link will fail), so double-check this before you start.
:::

![Selecting an IP phone from the CTI mode drop-down in the web client](/images/pbx/snom-cti-mode.png)

## What you can control from the web client

With the phone connected, the following call actions are available directly from the Cloud Voice App Web Client:

- Make and end a call
- Reject an incoming call
- Hold and resume a call
- Blind transfer a call
- Record a call

:::note
Transfers from this control panel are blind transfers: the call is handed straight to the destination without first speaking to the person you are transferring to. Plan for that if the receiver may need a heads-up before the call arrives.
:::