> ## Documentation Index > Fetch the complete documentation index at: https://docs.voxworks.ai/llms.txt > Use this file to discover all available pages before exploring further. # SIP Trunking & BYO Carrier > How Voxworks connects your calls to the phone network, what that means for bringing your own number or carrier, and how SIP URI transfer destinations fit in. ## Overview SIP trunking is the internet-based connection that links a voice platform to the traditional phone network. On Voxworks it is **fully managed for you**: when you add a phone number on the [Numbers & Routing](/numbers/overview) page, the underlying carrier connectivity is provisioned automatically. There are no trunk credentials to enter, no SIP settings to configure, and no capacity to plan — a number you add is ready to take and place calls straight away. This page explains what the managed connection covers, your options for using a number you already own, and how the **SIP URI** transfer destination in Endpoints differs from bringing your own carrier. *** ## What Voxworks manages for you When you claim a number from the **Numbers** tab (**Add number**), Voxworks handles the telephony layer end to end: * **Carrier connectivity** — the number is provisioned onto Voxworks' voice infrastructure automatically, ready for both inbound and outbound calls. Numbers are Australian numbers drawn from Voxworks' inventory. * **Capacity** — you never plan per-line capacity or channel counts. How many outbound calls your team can run at once is governed by your account's calling tier, not by the number — see [Dispatch & Concurrency](/calls/dispatch-and-concurrency). * **Regulatory registration** — numbers are registered against your team's service address; see [Service Addresses & Regulatory Verification](/numbers/service-addresses). Because the trunking layer is managed, there is nothing on this page you need to configure day to day. Assign a script to the number and calls just work. *** ## Using a number you already own You do not have to move your existing business number to Voxworks to put an AI agent on it. Today there is one self-serve path, plus others that go through the Voxworks team: | You want to… | Use this | | -------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Keep your existing number with your current carrier and have Voxworks answer its calls | **Call forwarding** — divert your number (all calls, or only unanswered ones) to your Voxworks number. See [Forward Your Existing Number](/numbers/forward-existing-number). | | Send callers from a Voxworks agent into your existing phone system | A **SIP URI** transfer destination on an Endpoint — not self-serve, set up with the Voxworks team. See the next section. | | Move (port) your existing number onto Voxworks | Not self-serve today — forwarding is the recommended approach. Speak to the Voxworks team if forwarding does not suit your setup. | | Connect your own carrier or SIP trunk directly to Voxworks | Not self-serve today. Speak to the Voxworks team to discuss direct carrier connectivity for your project. | Call forwarding is the right choice for almost every team: it is self-serve, takes a few minutes with standard carrier dial codes, and is fully reversible. The AI Receptionist editor includes a built-in forwarding-instructions generator — choose your **Carrier**, **Phone setup** and **When to forward**, and it produces the exact dial codes to use. The [Forward Your Existing Number](/numbers/forward-existing-number) guide covers it in full. *** ## SIP URI transfer destinations are not BYO carrier If you searched for "SIP" because you saw it in the app, you most likely found the **SIP URI** destination type on the **Endpoints** tab of Numbers & Routing. It is easy to confuse with SIP trunking, but it works in the opposite direction: * **SIP trunking / BYO carrier** would carry calls *into* Voxworks from your own carrier. This is not a self-serve feature today. * A **SIP URI endpoint** carries a caller *out of* a Voxworks call, transferring them to a SIP address on your own phone system — for example a desk extension, ring group or hosted PBX — instead of dialling a phone number. The **Destination** section when adding or editing an endpoint (**Add endpoint** on the Endpoints tab) shows the fields involved: | Setting | Description | Default | | ---------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------- | | Destination Type | Where the transfer goes: **Phone**, **Team member**, or **SIP URI**. | Phone | | SIP URI | The SIP address to transfer to, up to 255 characters. Required when the destination type is SIP URI, and must start with `sip:` — for example `sip:desk@example.com`. | — | During a call, a SIP URI endpoint behaves like any other transfer destination: the endpoint's schedule, location and department apply as usual when the agent chooses where to send the caller. See [Endpoints](/routing/endpoints) for the full endpoint configuration and [Transferring Calls](/routing/transferring-calls) for what callers experience during a transfer. No SIP destination or connection is self-serve — the **SIP URI** field shown above, SIP trunking, BYO carrier, and any other custom SIP setup are all configured directly with the Voxworks team, not something you set up yourself in the app. Contact the Voxworks team if your project needs this. *** ## Where you might see "Trunk" in the app One legacy label survives in the app: the Batch Scheduler's **Calling rules** section includes a field labelled **Trunk**. Despite the name, this simply selects which of your phone numbers a batch dials out from — it is the same choice as **Select Outbound Number** in the New Call modal. See [Outbound Caller ID & Default Number](/numbers/caller-id) for how the outbound number is resolved across calls, batches and automations. *** ## Next Steps * [Forward Your Existing Number](/numbers/forward-existing-number) — carrier-by-carrier dial codes to divert your current number to Voxworks. * [Phone Numbers](/numbers/overview) — claiming numbers, assigning scripts and managing your inventory. * [Endpoints](/routing/endpoints) — configure transfer destinations, including SIP URI, phone and team-member types. * [Outbound Caller ID & Default Number](/numbers/caller-id) — how the from-number is chosen for outbound calls.