# Generic SIP Trunk

Connect any SIP trunk or on-prem PBX to Bolna voice agents. Works with any telephony provider supporting standard SIP for full control of your setup.

## How Generic SIP Trunk fits in the stack

### Best for

Making and receiving real phone calls at production scale.

### Use this layer when

You need numbers, trunking, call routing, or carrier control.

### Connects to

STT, LLM, TTS, and workflow actions inside the live call.

## Telephony is the calling layer

This provider connects Bolna to the phone network. It controls how calls start, where they route, which numbers you use, and how the audio enters your agent pipeline.

Telephony > Phone Network > STT > Listener > LLM > Reasoning > TTS > Voice > Tools > Actions

This page focuses on where Generic SIP Trunk fits in a production voice stack.

# Overview

Session Initiation Protocol (SIP) is the industry standard protocol for voice over IP communications. With Bolna's generic SIP integration, you can connect any SIP-compatible trunk or PBX to power your voice agents giving you complete control over your telephony infrastructure and carrier relationships.

This integration works with any Internet Telephony Service Provider (ITSP), on-premises PBX, or SIP-enabled infrastructure that follows RFC 3261 standards. Perfect for enterprises with existing telephony investments or specific carrier requirements.

## Features & Use Cases

**Total Freedom (Carrier Independence)**  
Work with any SIP phone provider you want. This means you are never locked into one company and can always shop around for the best rates and terms.

**Bring Your Own Provider**  
Already have a telecom provider you love with great rates? Perfect! You can easily plug them directly into Bolna's AI agents.

**Connect to Your Existing Phone System**  
Easily link Bolna's AI to your current office phone system (like Cisco, Avaya, or Asterisk) to upgrade your standard phone menus with smart conversational AI.

**Local Presence Anywhere**  
Use different local phone providers in different countries to ensure clear, fast calls and a true local feel for your global customers.

**Keep Call Costs Low**  
Pick and choose the most affordable phone carriers for your massive call volumes while still using all of Bolna's advanced AI features.

**Use Case: Upgrading Office Phone Systems**  
Great for big companies that want to make their existing phone systems smarter by replacing old menu systems with actual AI conversations.

**Use Case: Guaranteed Reliability**  
Set up multiple phone providers at the same time so if one carrier goes down, your calls automatically switch to another without dropping.

**Use Case: Staying Compliant Locally**  
Perfect for connecting with specific, strictly regulated local phone companies to make sure you follow all regional telecom and data privacy rules correctly.

## Technical Details

### Supported Codecs

- **G.711 (PCMU)**: 64 kbps, standard quality, minimal latency
- **G.711 (PCMA)**: 64 kbps, European variant
- **G.729**: 8 kbps, lower bandwidth (if supported by trunk)

### Authentication Methods

- **Digest Authentication**: Username/password-based (RFC 2617)
- **IP Authentication**: Whitelist-based, no credentials needed

### Transport Protocols

- **UDP**: Lightweight, standard for SIP (port 5060)
- **TCP**: Reliable, for stable connections (port 5060)
- **TLS**: Encrypted, secure SIP (port 5061)

## Carrier-Specific Guides

For streamlined setup with specific carriers, see our dedicated guides:

- Twilio SIP Trunking
- Plivo SIP Trunking
- Exotel SIP
- Acefone SIP
- Airtel SIP Trunking

## Other providers in this layer

- **Exotel**  
Connect Exotel to Bolna voice agents for reliable inbound and outbound calling across India.
- **Plivo**  
Use Plivo telephony with Bolna voice agents for affordable inbound and outbound calling in India.
- **Twilio**  
Connect Twilio to Bolna for global phone coverage.

## See where Generic SIP Trunk fits in your production workflow

Use the demo to walk through provider selection, stack tradeoffs, and the exact workflow you want Bolna to automate.