SIP
G

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.

sipbyottrunkpbxgeneric
At a glance

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.

Voice Stack

Telephony is the calling layer

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.

TelephonyPhone Network
STTListener
LLMReasoning
TTSVoice
ToolsActions

This page focuses on where Generic SIP Trunk fits in a production voice stack. For full setup steps, credentials, and API details, use the documentation link above.

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:

Browse this layer

Keep exploring the voice stack

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Telephony

Telephony providers connect your voice agents to the phone network so they can make and receive real calls. Bolna supports managed integrations with major carriers as well as bring-your-own-carrier via SIP trunking, giving you full control over call routing, number provisioning, and cost.

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Large Language Models

The LLM is the brain of your voice agent. It understands what callers say and decides how to respond. Bolna lets you swap between models like GPT-4o, Claude, and DeepSeek without changing your agent configuration, so you can optimize for speed, cost, or reasoning depth.

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Speech-to-Text

Speech-to-text converts what callers say into text that your LLM can process. Transcription accuracy and latency directly affect how natural a conversation feels. Bolna supports streaming STT providers optimized for telephony audio, including specialized models for Indian languages.

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Text-to-Speech

Text-to-speech turns your agent responses into spoken audio. Voice quality shapes how callers perceive your brand. Flat, robotic speech kills trust while natural, expressive voices build it. Bolna integrates with the fastest TTS providers so responses sound human and arrive without awkward pauses.

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Tools & Workflows

Tools let your voice agents take action during a call, not just talk. Book a calendar slot, look up an order in Shopify, push a lead into your CRM, or trigger a multi-step automation in Zapier. These integrations turn voice agents from answering machines into workflow engines.

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.