> For the complete documentation index, see [llms.txt](https://docs.voipnumber.net/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.voipnumber.net/components/connection.md). # Connection {% hint style="info" %} `Connection` describes something that can be dialled 🔔 and make calls ☎️ 📞 In the world of VoIP (SIP), a Connection is a `SIP` endpoint (SIP device) {% endhint %} Setup your SIP Connections at [app.voipnumber.net/connections](https://app.voipnumber.net/connections)

2 Connections: Bob and Alice

## VoIP and SIP VoIP (Voice over Internet Protocol) and IMS (IP Multimedia Subsystem) are sending voice calls in digital packets over the Internet as opposed to sending them as analog voltage signals, as was the case with the old telephony lines. VoIP is based on the `SIP` protocol, and whenever someone says `VoIP` you can think of it as `SIP`. We will name all devices that you can connect to `VoIP` networks a `SIP` endpoints, SIP phones, or SIP devices `SIP` devices can be divided into 3 categories: * `IP phones` * `Softphones` * and others, like: `intercoms, alarms, doorbells,` etc. IP phones are hardware that you can put on your desk, and so they are frequently referred to as desk phones. The most popular desk phones are produced by Yealink, Cisco, and Polycom Softphones are similar, but they do not have a handset or headset, they are just programs, a software that uses your computer's or your mobile phone's microphone and speaker as audio interfaces In any case, `SIP` device must be registered with `VoIP` provider to receive calls It's very simple and it takes less than 2 minutes to get done on [VoIP Number](https://app.voipnumber.net/dashboard) ## Creating a Connection When you create a `Connection`, you define 3 parameters: * `Name` * `SIP user` * `SIP password` To create a Connection, go to the Connections tab on VoIP Number ([app.voipnumber.net/connections](https://app.voipnumber.net/connections)) and click `ADD`. Fill in these 3 parameters and click `ADD` or press `ENTER`

Creating a Connection

## Register Connection Only `Name` and `SIP user` are mandatory when you are creating a new Connection but if you want to register to a Connection you should set a `SIP password` as well (not always you need to register to a Connection, see [#virtual-connection](#virtual-connection "mention") below) Connection's `SIP user` and `SIP password` are `SIP` credentials which let you register from a `SIP` device ☎️ of your choice as a Connection for making and answering calls `SIP user` is just a different name for an extension. This can be any text and it doesn't have to be a number. It must be a unique name on [VoIP Number](https://app.voipnumber.net/dashboard) - a notification dialog will inform you if the name is already taken Once `Connection` is added, you need to open configuration settings on your `SIP` device and use the parameters you set up for the Connection (`Name`, `SIP user,` `SIP password`). If it is asking you about a `SIP` domain (SIP provider, VoIP provider, SIP server, or similar type of thing) type `sip.voipnumber.net` Once it's done, click `REGISTER` on your SIP device and you will get online immediately ✅ `SIP` devices differ in how they present these settings to the user on their UI. Check out these quick guides for more details and a handful of examples for setting up Zoiper, Bria, and Yealink IP desk phones: * [Register a Softphone (SIP phone)](/guides/register-a-softphone-sip-phone.md) * [Register IP desk phone](/guides/register-ip-desk-phone.md) ## Virtual Connection As we said earlier you may want to create `Connections` only to execute [Call Flows](https://app.voipnumber.net/callflows). For example to play a text announcement to the call, play an audio file, collect digits (DTMF), or bridge a call to a Connection. In this case, you do not need to register to such a Connection from any `SIP` device and we call it *virtual* Connection 👻. It just defines what happens to a call by having a Call Flow attached (or voicemail enabled), no device is needed 😊 ## Dialing a Connection To dial `Connection` from a `SIP` device registered on [VoIP Number](https://app.voipnumber.net/dashboard) simply call a `SIP USER NAME` associated with the Connection. To dial Connection from the telephony network you need a [Number](/components/number.md) ### Inbound Action (Connection's inbound action) When you dial a `Connection`, the call is executed according to the `Inbound Action` set on a Connection. This Inbound Action is either: * `default` (bridge) * `Call Flow` By default new Connection has `Inbound Action` set to `default` (bridge). That means that by default a call is sent to the `SIP` device registered on [VoIP Number](https://app.voipnumber.net/dashboard) to the Connection's `SIP` credentials and then to its [Voicemail with audio transcription](/features/voicemail-with-audio-transcription.md), if the call was not answered

Call between SIP users (Connection defines SIP User name)

However, if a `Connection` has [Call Flow](/components/call-flow.md) attached, Inbound Action is changed to `Call Flow` and a call is running through actions defined in Call Flow instead. Call Flows are very flexible, you can set them up to bridge (transfer) a call to Connection or to play some speech from text before a transfer, or maybe send a call to a voicemail, you got it - possibilities are endless

Connection with Call Flow attached

### Number The other useful change to a `Connection` that you can easily make is attaching a [Number](/components/number.md) to it, and we will discuss that in next sections 🤓 😊 --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.voipnumber.net/components/connection.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.