> ## Documentation Index
> Fetch the complete documentation index at: https://www.vobiz.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Vobiz Cloud Telephony: Numbers, Calls, IVR and SIP Trunks

> Yes, Vobiz provides cloud telephony: phone numbers, voice calls, IVR, SIP trunking, recording, conferencing, SMS and WhatsApp, on one platform and API.

*November 3, 2026 · By [Piyush Sahoo](https://www.linkedin.com/in/piyush-s713/)*

Yes. Vobiz is a cloud telephony provider. You can buy phone numbers, make and receive calls, build IVR menus, record calls, run conferences, connect your PBX over SIP trunks, and send SMS and WhatsApp messages. It all runs on the Vobiz platform, and you manage it from the Vobiz Console or the REST API.

> [!NOTE]
>
> **Key takeaways**
>
> * Cloud telephony moves your numbers, routing, and recording from office hardware to a provider's platform.
> * Vobiz covers voice, SIP trunks, recording, conferencing, SMS, and WhatsApp under one set of credentials.
> * You can run call flows on Vobiz through VobizXML, or keep your PBX and connect it over a SIP trunk.
> * Indian numbers and domestic routes carry extra eligibility, KYC, and number series rules.

## What is cloud telephony?

Cloud telephony is a phone system that runs on a provider's platform instead of on equipment in your office. The provider hosts the numbers, call routing, and recording. You manage them over the internet through a web console or an API.

You may also see it called hosted telephony or internet telephony. The "cloud" part follows [NIST's definition of cloud computing](https://csrc.nist.gov/pubs/sp/800/145/final): shared resources that you provision and release on demand, with little management effort.

For your business, that changes three things:

* **No PBX hardware to buy.** Vobiz hosts your numbers and carries your calls, and your team can answer on softphones, IP phones, or WebRTC clients.
* **Changes happen in software.** You add a number, point it at a different call flow, or raise capacity from the Console or the API.
* **One account covers every channel.** Voice, SIP trunks, SMS, and WhatsApp all use the same Vobiz Auth ID and Auth Token.

### How it differs from an on-premise PBX, VoIP, and SIP trunking

These terms overlap, so it helps to separate them.

| Term | What it means | How it relates to Vobiz |
| - | - | - |
| **On-premise PBX** | A phone system on hardware you run yourself. A cloud setup removes most of that equipment, leaving IP phones and an internet connection. | Keep your PBX and [connect it over a trunk](https://www.vobiz.ai/docs/trunks.md), or replace it with [endpoints](https://www.vobiz.ai/docs/endpoint.md) and VobizXML. |
| **VoIP** | The technology that carries voice over the internet. Cloud telephony is the hosted service built on top of it. | Vobiz gives you the service, so you work with numbers and call flows. |
| **SIP trunking** | One part of cloud telephony: the connection that carries calls between a provider and your own PBX, SBC, or AI platform. | Use [SIP trunks](https://www.vobiz.ai/docs/trunks.md) alone or alongside programmable call flows. |

## What cloud telephony does Vobiz provide?

Each capability below has its own Vobiz documentation.

| Capability | What you can do on Vobiz | Docs |
| - | - | - |
| **Phone numbers** | Browse inventory by country, then buy, assign, and release numbers. India series include 140, 160, 1800, and 92. | [Buy a phone number](https://www.vobiz.ai/docs/buy-a-phone-number.md), [Phone Numbers API](https://www.vobiz.ai/docs/account-phone-number.md), [India number series](https://www.vobiz.ai/docs/faq/number-series.md) |
| **Inbound and outbound calls** | Place calls by API, receive calls on your numbers, hang up, and detect answering machines. | [Call management](https://www.vobiz.ai/docs/call/overview.md), [Machine detection](https://www.vobiz.ai/docs/call/machine-detection.md) |
| **IVR** | Build menus that take keypad or speech input, speak text, and play audio, using VobizXML. | [How VobizXML works](https://www.vobiz.ai/docs/xml/overview/how-it-works.md), [Gather](https://www.vobiz.ai/docs/xml/gather.md), [Cloud IVR](https://www.vobiz.ai/docs/solutions/cloud-ivr.md) |
| **Call routing and transfer** | Connect a caller to a phone number or SIP user, and move a live call to a new call flow. | [Dial](https://www.vobiz.ai/docs/xml/dial.md), [Transfer a call](https://www.vobiz.ai/docs/call/transfer-call.md) |
| **SIP trunking** | Connect a PBX or AI platform with IP or credential authentication, call limits, and priority-based failover. | [SIP trunks](https://www.vobiz.ai/docs/trunks.md), [SIP trunking concepts](https://www.vobiz.ai/docs/concepts/sip-trunking.md) |
| **Bring Your Own Carrier** | Keep your carrier, SBC, or PBX and route that traffic through Vobiz. | [BYOC](https://www.vobiz.ai/docs/concepts/bring-your-own-carrier.md) |
| **SIP endpoints** | Register softphones, IP phones, and WebRTC clients to make and receive calls. | [Endpoints](https://www.vobiz.ai/docs/endpoint.md) |
| **Call recording** | Record calls and conferences in MP3 or WAV, with optional transcription, then list and download the files. | [Record calls](https://www.vobiz.ai/docs/call/record-calls), [Recordings API](https://www.vobiz.ai/docs/recording.md), [Call recording](https://www.vobiz.ai/docs/solutions/call-recording.md) |
| **Conferencing** | Bring callers into named rooms, then mute, deafen, or remove members and record the session. | [Conference element](https://www.vobiz.ai/docs/xml/conference.md), [Conference members](https://www.vobiz.ai/docs/conference/members.md), [Conference recording](https://www.vobiz.ai/docs/conference/recording.md) |
| **Live audio streaming** | Send live call audio to your WebSocket server, and send audio back in bidirectional mode. | [Audio streams](https://www.vobiz.ai/docs/audio-streams.md), [Stream element](https://www.vobiz.ai/docs/xml/stream.md) |
| **AI voice agents** | Connect platforms such as Vapi, Retell, ElevenLabs, Pipecat, and LiveKit to real phone numbers. | [Build an AI voice agent](https://www.vobiz.ai/docs/guides/ai-voice-agent.md), [Integrations](https://www.vobiz.ai/docs/integrations.md) |
| **Outbound campaigns** | Run campaigns with CSV contact lists, caller ID pools, retries, and scheduling. | [Campaign Manager API](https://www.vobiz.ai/docs/campaign-manager/overview.md), [Campaigns in the Console](https://www.vobiz.ai/docs/platform/campaigns/list.md) |
| **Webhooks (callbacks)** | Receive an HTTP request on your server when a call, recording, or conference event happens. | [Webhooks (callbacks)](https://www.vobiz.ai/docs/concepts/callbacks.md), [Trunk webhooks](https://www.vobiz.ai/docs/trunks/webhook.md) |
| **Call records and reporting** | Filter and export call detail records with billing data, hangup attribution, and quality metrics. | [Call Detail Records](https://www.vobiz.ai/docs/cdr.md) |
| **SMS, MMS, and RCS** | Send and receive messages, run broadcasts, and manage conversations and opt-outs. | [Messaging API](https://www.vobiz.ai/docs/sms/overview.md) |
| **WhatsApp Business API** | Send templates, run campaigns, manage conversations, and receive webhooks. | [WhatsApp on Vobiz](https://www.vobiz.ai/docs/whatsapp/getting-started/introduction.md), [WhatsApp API](https://www.vobiz.ai/docs/whatsapp/api.md) |
| **Capacity controls** | Buy capacity for how many calls run at once and how fast new calls start. | [Concurrency](https://www.vobiz.ai/docs/platform/capacity/concurrency.md), [CPS](https://www.vobiz.ai/docs/platform/capacity/cps.md) |
| **Sub-accounts** | Give each customer isolated credentials, numbers, and usage tracking. | [Sub-accounts](https://www.vobiz.ai/docs/sub-accounts.md) |
| **Vobiz Console** | Manage numbers, applications, trunks, call logs, recordings, and credentials in one web app. | [Console dashboard](https://www.vobiz.ai/docs/platform/dashboard.md), [Voice](https://www.vobiz.ai/docs/platform/voice/overview.md), [SIP trunking](https://www.vobiz.ai/docs/platform/sip/overview.md) |

## How the pieces fit together

Vobiz sits between your customers and your business systems. Customers reach you over public phone and messaging networks. Your systems connect to Vobiz through the REST API, webhooks (callbacks), SIP, or a WebSocket audio stream.

![Three layers. Your customers reach Vobiz by phone call, SMS, MMS, RCS, and WhatsApp over public networks. The Vobiz cloud holds phone numbers, voice calls, IVR and VobizXML, SIP trunks, recording, conferencing, call records, and messaging, managed in the Console or by API. Your business connects by REST API, webhooks (callbacks), SIP, and WebSocket audio from a web server or CRM, PBX or SBC, AI voice agent, or softphones.](https://mintcdn.com/vobizai/jCEy4ewYXKv2PUab/images/solutions/cloud-telephony/cloud-telephony-layers-light.svg?fit=max\&auto=format\&n=jCEy4ewYXKv2PUab\&q=85\&s=2cf691ee44aa55a2945292a499189c9f)

## How Vobiz handles an inbound call

Once you buy a number, you choose how it routes calls. There are two main routes.

![An inbound call to your Vobiz number takes one of two routes. Through an XML Application, Vobiz requests your answer URL and runs the VobizXML you return, which can drive an IVR menu, a phone number, a SIP endpoint, a conference, or an audio stream. Through a SIP trunk, Vobiz forwards the call to your origination URI, which reaches your PBX, SBC, or AI voice platform. Both routes offer webhooks (callbacks), plus call logs and recordings in the Console.](https://mintcdn.com/vobizai/jCEy4ewYXKv2PUab/images/solutions/cloud-telephony/number-routing-light.svg?fit=max\&auto=format\&n=jCEy4ewYXKv2PUab\&q=85\&s=020859643a6806fede6824946ff943e2)

* **Attach the number to an XML Application.** Vobiz requests your `answer_url` when a call arrives and runs the VobizXML your server returns. Your code decides what happens next, so it can look up the caller or apply business rules. See [Attach a number](https://www.vobiz.ai/docs/applications/attach-number.md).
* **Assign the number to a SIP trunk.** Vobiz forwards the call to the origination URI you set, such as your PBX or AI voice platform. Your own system then controls the call. See [Assign a number to a trunk](https://www.vobiz.ai/docs/trunks/assign-number.md).

For outbound calls, your application calls the [Make a Call API](https://www.vobiz.ai/docs/call/make-call.md), your PBX sends calls over a trunk, or you run a [campaign](https://www.vobiz.ai/docs/campaign-manager/overview.md).

## What businesses build with it

* **Self-service phone menus:** a [cloud IVR](https://www.vobiz.ai/docs/solutions/cloud-ivr.md) that answers routine questions and routes the rest.
* **Contact centres:** [custom voice operations](https://www.vobiz.ai/docs/solutions/contact-centre.md) assembled from numbers, routing, recording, and call records.
* **AI voice agents:** [phone-based agents](https://www.vobiz.ai/docs/solutions/ai-voice-agent.md) on your existing AI platform.
* **Outbound calling:** [automated campaigns](https://www.vobiz.ai/docs/solutions/automated-outbound-calling.md) and [appointment reminders](https://www.vobiz.ai/docs/solutions/appointment-reminders.md).
* **Private calling:** [number masking](https://www.vobiz.ai/docs/solutions/number-masking.md) for marketplaces and delivery apps.
* **Multi-party calls:** [conference calling](https://www.vobiz.ai/docs/solutions/conference-calling.md) for teams and customers.

## What engineers should know

Vobiz builds on open standards, so your team works with protocols it already knows.

| Layer | Standard | Where you meet it on Vobiz |
| - | - | - |
| **Call signalling** | SIP, [RFC 3261](https://www.rfc-editor.org/rfc/rfc3261.txt) (June 2002) | [SIP trunks](https://www.vobiz.ai/docs/trunks.md) and [SIP endpoints](https://www.vobiz.ai/docs/endpoint.md) |
| **Call media** | RTP, [RFC 3550](https://www.rfc-editor.org/rfc/rfc3550.txt) (July 2003) | [IP whitelisting](https://www.vobiz.ai/docs/concepts/ip-whitelisting.md) lists the signalling and media addresses to allow |
| **Live audio to your server** | WebSocket, [RFC 6455](https://www.rfc-editor.org/rfc/rfc6455.txt) (December 2011) | [Audio streams](https://www.vobiz.ai/docs/audio-streams.md) |
| **Browser calling** | [WebRTC](https://www.w3.org/TR/webrtc/) (W3C Recommendation, March 2025 version) | [WebRTC Playground](https://www.vobiz.ai/docs/integrations/webrtc-application-setup.md) and [SIP endpoints](https://www.vobiz.ai/docs/endpoint.md) |
| **Business messaging** | [WhatsApp Business Platform](https://developers.facebook.com/documentation/business-messaging/whatsapp/about-the-platform) from Meta | [WhatsApp API](https://www.vobiz.ai/docs/whatsapp/api.md) |

Every REST request carries your credentials in the `X-Auth-ID` and `X-Auth-Token` headers. See [Vobiz authentication](https://www.vobiz.ai/docs/api-reference/authentication.md) for details.

## Cloud telephony in India

India has its own telecom rules, so check these before you plan a deployment. The [India calling regulations](https://www.vobiz.ai/docs/compliance/india/calling-regulations.md) page has the full list.

* **Eligibility:** Businesses registered in India can rent Indian numbers and use domestic routes. Businesses elsewhere use international routes.
* **KYC:** You complete [India number KYC](https://www.vobiz.ai/docs/compliance/india/kyc.md) before you rent an Indian number.
* **Media anchoring:** Both legs of a domestic call stay within India.
* **Consent:** Commercial calls need explicit digital consent. See [UCC management](https://www.vobiz.ai/docs/compliance/india/ucc.md).
* **Number series:** TRAI's [2025 amendment to its commercial communication rules](https://trai.gov.in/sites/default/files/2025-02/PR_No.11of2025.pdf) keeps promotional calls on the 140 series and designates the 1600 series for service and transactional calls.

TRAI says the 1600 series [is assigned to BFSI entities and government organisations](https://www.trai.gov.in/sites/default/files/2025-11/PR_No.135of2025.pdf). It set adoption deadlines by sector in November 2025, and [insurers had until February 15, 2026](https://trai.gov.in/sites/default/files/2025-12/PR_No.151of2025.pdf).

To request a [140, 160, or 92 series number](https://www.vobiz.ai/docs/faq/number-series.md), contact the Vobiz team. Vobiz docs use "160 series" for the same numbers TRAI calls 1600.

## How to get started

> [!WARNING]
>
> Buying a number debits your balance, and placing a call reaches a real person and is billed. Use your own credentials, and confirm each of these actions before you run it.

**1. Create your account**

Sign up at [console.vobiz.ai](https://console.vobiz.ai/app/register). Your **Auth ID** and **Auth Token** are on the [dashboard](https://www.vobiz.ai/docs/platform/dashboard.md).

**2. Complete KYC verification**

Submit your [verification documents](https://www.vobiz.ai/docs/faq/verification-docs.md) before you buy live numbers or launch outbound campaigns. For India, also read the [calling regulations](https://www.vobiz.ai/docs/compliance/india/calling-regulations.md).

**3. Get a number**

[Buy a number](https://www.vobiz.ai/docs/buy-a-phone-number.md) in the Console or by API. Check its capabilities and fees first. To keep your current carrier, follow [Bring Your Own Carrier](https://www.vobiz.ai/docs/concepts/bring-your-own-carrier.md) instead.

**4. Route the number**

Attach it to an [XML Application](https://www.vobiz.ai/docs/applications/attach-number.md) or assign it to a [SIP trunk](https://www.vobiz.ai/docs/trunks/assign-number.md).

**5. Test your first call**

Follow the [Vobiz quick start](https://www.vobiz.ai/docs/quick-start.md), then add [webhooks (callbacks)](https://www.vobiz.ai/docs/concepts/callbacks.md) and [recording](https://www.vobiz.ai/docs/call/record-calls) as you need them.

## FAQ

> [accordion] What is cloud telephony?
>
> Cloud telephony is a phone system that runs on a provider's platform instead of on equipment in your office. The provider hosts the numbers, call routing, and recording. You manage them over the internet through a web console or an API.

> [accordion] Does Vobiz provide cloud telephony?
>
> Yes. Vobiz provides phone numbers, inbound and outbound calling, IVR, SIP trunking, call recording, conferencing, webhooks (callbacks), call detail records, SMS, and the WhatsApp Business API. You manage them from the [Vobiz Console](https://www.vobiz.ai/docs/platform/dashboard.md) or the [Vobiz API](https://www.vobiz.ai/docs/api-reference).

> [accordion] Do I need PBX hardware to use Vobiz?
>
> No. Vobiz hosts your numbers and trunks, and your team can take calls on softphones, IP phones, or WebRTC clients through [SIP endpoints](https://www.vobiz.ai/docs/endpoint.md). If you already run a PBX, you can connect it with a [SIP trunk](https://www.vobiz.ai/docs/trunks.md).

> [accordion] Can I use my existing carrier and phone numbers with Vobiz?
>
> Yes. With [Bring Your Own Carrier](https://www.vobiz.ai/docs/concepts/bring-your-own-carrier.md), your numbers stay with your current provider and you route that traffic through Vobiz. You can also [buy a new number](https://www.vobiz.ai/docs/buy-a-phone-number.md) from Vobiz inventory.

> [accordion] Do I need developers to use Vobiz?
>
> It depends on what you build. Numbers, trunks, call logs, recordings, and capacity are all in the Vobiz Console. A custom IVR needs a web server that returns VobizXML, so plan for a developer or technical partner. The [Visual XML Builder](https://www.vobiz.ai/docs/xml-builder.md) helps you prototype call flows, and [Integrations](https://www.vobiz.ai/docs/integrations.md) has setup guides for AI voice platforms.

> [accordion] Is Vobiz cloud telephony available in India and other countries?
>
> Yes. Vobiz is available in 130+ countries, and you can filter number inventory by country. Indian numbers and domestic calling follow TRAI and DoT rules, including eligibility and KYC. See [India calling regulations](https://www.vobiz.ai/docs/compliance/india/calling-regulations.md) before you plan an India deployment.

## Further reading on Vobiz

* [Vobiz introduction](https://www.vobiz.ai/docs/introduction.md)
* [SIP trunking concepts](https://www.vobiz.ai/docs/concepts/sip-trunking.md)
* [What is a voice API?](https://www.vobiz.ai/docs/blogs/what-is-a-voice-api.md)
* [What is SIP trunking?](https://www.vobiz.ai/docs/blogs/what-is-sip-trunking.md)
* [Vobiz quick start](https://www.vobiz.ai/docs/quick-start.md)

## Sources

Read on November 3, 2026.

* TRAI: [Press Release No. 11/2025, amendments to TCCCPR 2018](https://trai.gov.in/sites/default/files/2025-02/PR_No.11of2025.pdf)
* TRAI: [Press Release No. 135/2025, 1600-series adoption by RBI, SEBI, and PFRDA entities](https://www.trai.gov.in/sites/default/files/2025-11/PR_No.135of2025.pdf)
* TRAI: [Press Release No. 151/2025, 1600-series adoption by IRDAI entities](https://trai.gov.in/sites/default/files/2025-12/PR_No.151of2025.pdf)
* NIST: [SP 800-145, The NIST Definition of Cloud Computing](https://csrc.nist.gov/pubs/sp/800/145/final)
* IETF: [RFC 3261, SIP: Session Initiation Protocol](https://www.rfc-editor.org/rfc/rfc3261.txt)
* IETF: [RFC 3550, RTP: A Transport Protocol for Real-Time Applications](https://www.rfc-editor.org/rfc/rfc3550.txt)
* IETF: [RFC 6455, The WebSocket Protocol](https://www.rfc-editor.org/rfc/rfc6455.txt)
* W3C: [WebRTC: Real-Time Communication in Browsers](https://www.w3.org/TR/webrtc/)
* Meta: [About the WhatsApp Business Platform](https://developers.facebook.com/documentation/business-messaging/whatsapp/about-the-platform)

> [card] [Talk to the Vobiz team](https://www.vobiz.ai/contact-us/)
>
> Want help choosing the right setup? Tell us what you're building.


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