# Call Overview

The Cloud Voice App lets you reach coworkers and outside contacts through both audio and video calls. This page covers what your system needs to place each type of call, along with the call-handling features the desktop app supports.

## Requirements

:::note
The settings below live on the PBX server (Private Branch Exchange, the phone system that routes your organization's calls), not in the app. You cannot change them yourself, so if a call type will not connect, your system administrator is the person who confirms and adjusts them. A codec (coder/decoder) is the software that compresses call audio or video so it can travel over the network and unpacks it at the other end. Both ends of a call must share at least one codec.
:::

### Audio calls

Before you can place audio calls, ask your system administrator to confirm that the following are set on the PBX server:

- **Web Server Protocol**: HTTPS (the encrypted version of web traffic).
- **Codec**: At least one of u-law, a-law, or G722 is enabled.

:::caution
If none of those audio codecs is enabled on the server, audio calls will fail to connect. The app and the server need at least one codec in common.
:::

### Video calls

Video calls need everything listed above, plus the following on the PBX server:

- **PBX Plan**: Ultimate Plan.
- **Codec**: Either VP8 or H264 is enabled.

:::caution
Video calling is only available on the Ultimate Plan. On any lower plan, video calls will not work even when a video codec is enabled.
:::

:::tip
VP8 is the recommended video codec. When both VP8 and H264 are enabled, set VP8 to the highest priority so the app uses it first.
:::

## Supported call features

The desktop app supports the call-handling features below. Follow each link for step-by-step instructions.

| Feature | What it does |
| --- | --- |
| [Audio Conferencing](/pbx/desktop-client-user-guide/audio-conferencing-overview/) | Start an instant audio conference during a call by dialing extra people in. Up to 9 members can join. |
| [Send to Voicemail](/pbx/desktop-client-user-guide/forward-an-incoming-call-to-voicemail/) | Route an incoming call straight to your voicemail with a single click on the incoming-call pop-up. |
| [Call Flip](/pbx/desktop-client-user-guide/flip-an-active-call-between-devices/) | Move a live call from the Cloud Voice App to another device where your extension is registered, without dropping the conversation. |
| [Call Switch](/pbx/desktop-client-user-guide/continue-an-active-call-on-cloud-voice-app-desktop-client/) | Pull a live call from another registered device onto the Cloud Voice App, without dropping the conversation. |
| [Call Park](/pbx/desktop-client-user-guide/park-a-call/) | Hold a live call on a parking slot chosen by the system or by you, so you or a coworker can pick it up from another phone. |
| [Call Merge](/pbx/desktop-client-user-guide/merge-calls-into-an-audio-conference-call/) | Combine two or more live calls into a single audio conference that you host and manage. |
| [Call Hold/Resume](/pbx/desktop-client-user-guide/hold-and-resume-a-call/) | Pause a conversation without hanging up and pick it back up when you are ready. You can keep up to 6 calls on hold at once. |
| [Call Transfer](/pbx/desktop-client-user-guide/transfer-a-call/) | Hand off an in-progress call to another number, for example when a caller reaches the wrong person or team. |
| [Call Recording](/pbx/desktop-client-user-guide/record-a-call/) | Record a call and play it back later to review or confirm details. |
| [Call Note](/pbx/desktop-client-user-guide/add-notes-to-a-call/) | Add tags and remarks during a call, then review or edit them in the call log afterward. |
| [Send Call Details via Email](/pbx/desktop-client-user-guide/send-call-details-via-email/) | Email a call's details (contact information, call notes, and AI summary) to specific addresses for follow-up, during or after the call. |
| [Call Transcription](/pbx/desktop-client-user-guide/transcribe-a-call/) | Turn a call into readable text in real time and generate a summary automatically after it ends. |

:::note
Call Switch and Call Flip both move a live call between devices, just in opposite directions: Call Switch pulls a call onto the Cloud Voice App, while Call Flip pushes it out to another device. Either way, the conversation stays connected the whole time.
:::

:::caution
Recording a call can be subject to consent and notification laws that differ by location. Check what your area requires, and notify the other party if needed, before you record.
:::