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SIP Integration with SigmaMind

SIP (Session Initiation Protocol) is the backbone of modern voice communication. Using SIP, you can connect phone numbers purchased from external providers (such as Twilio, Vonage, or Telnyx) directly into the SigmaMind platform. This enables your AI agents to send and receive calls just like a real human agent.

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What is SIP?

SIP (Session Initiation Protocol) is a communication protocol used to set up and manage real-time sessions, such as voice and video calls, over the internet. SIP does not transmit the audio itself. Instead, it handles the signaling — initiating, modifying, and terminating communication sessions. The actual voice data flows over a separate protocol called RTP (Real-Time Transport Protocol).
Think of SIP as the signal that establishes the call, while RTP is the data channel that carries the actual voice.

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Key Terms in SIP

Before integrating, here are some common terms you may encounter:
  • SIP Trunking – A virtual connection that replaces traditional phone lines, enabling multiple calls over the internet.
  • DID (Direct Inward Dialing) – A virtual phone number assigned to your SIP trunk for inbound calls.
  • VoIP (Voice over IP) – Technology for transmitting voice over the internet.
  • PBX (Private Branch Exchange) – A private telephone network within an organization.
  • PSTN (Public Switched Telephone Network) – The traditional landline network.
  • SIP URI – An address (e.g., sip:user@domain.com) used to identify SIP endpoints.
  • SIP Registrar – The server that registers your number or device with the SIP network.
  • SIP Proxy – Routes SIP requests between devices and providers.
You do not need to memorize all these terms. A basic understanding is useful when configuring or troubleshooting SIP.

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Why Use SIP with SigmaMind?

SIP integration allows you to bring your own numbers into SigmaMind, regardless of which provider you use. With this approach, you can:
  • Keep your existing provider (Twilio, Vonage, Telnyx, etc.).
  • Import your number into SigmaMind via SIP.
  • Allow your AI agent to answer inbound calls and make outbound calls.
  • Scale without relying on SIM cards or physical telecom hardware.

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How SIP Integration Works in SigmaMind

The high-level process looks like this:
  1. Purchase a number from a SIP-supported provider.
  2. Obtain SIP credentials (domain, username, password, proxy/server details).
  3. Configure SIP settings in the SigmaMind Dashboard under Phone Numbers.
  4. SigmaMind connects to your SIP trunk, acting as a virtual softphone.
  5. Calls to your number are routed into your AI agent in real time.
Your phone number remains with your provider. SigmaMind only manages the call flow and AI interaction.

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Step-by-Step: Integrating SIP Numbers

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1. Purchase a Number

Obtain a number from a SIP-supported provider such as:

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2. Collect SIP Credentials

From your provider, gather the following details:
  • SIP Domain / Server
  • SIP Username
  • SIP Password
  • SIP Proxy / Registrar (if required)

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3. Configure in SigmaMind

In the SigmaMind Dashboard:
  1. Navigate to Phone Numbers.
  2. Click Add Phone Number.
  3. Enter the Phone number and SIP credentials provided by your provider.
  4. Save the configuration and test the connection.

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4. Assign Number to an Agent

  • Go to Phone Numbers.
  • Select your imported SIP number.
  • Assign it to an Inbound AI Agent and Outbound AI Agent.
At this point, your agent is ready to handle inbound and outbound calls using the configured number.

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Example: SIP Settings

Example configuration for Twilio: 
SIP Domain: your-domain.pstn.twilio.com
Username: your-sip-username
Password: your-sip-password
Proxy/Registrar: sip.twilio.com
Transport: TLS
Port: 5061
The exact values will vary depending on your provider. Always confirm with their documentation.

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Troubleshooting

  • 401 Unauthorized – Incorrect username or password.
  • 404 Not Found – Number not configured properly on the provider’s side.
  • One-way audio – Likely an RTP or firewall issue. Ensure correct media ports are open.
  • Call drops after a few seconds – Could be caused by NAT issues or SIP session timer settings.
If problems persist, test your credentials with a softphone application such as Zoiper or Linphone. This helps verify provider setup before connecting with SigmaMind.

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Summary

  • SIP is the protocol that connects external phone numbers to SigmaMind.
  • Any SIP-supported provider (Twilio, Vonage, Telnyx, etc.) can be used.
  • Configure SIP credentials in SigmaMind to integrate your number.
  • Once set up, your AI agent can seamlessly handle both inbound and outbound calls.
SIP integration gives you flexibility, scalability, and freedom to choose your telecom provider, while letting SigmaMind power intelligent, AI-driven voice communication.