# Public Switched Telephone Network (PSTN) connectivity guides

Use Twilio Programmable Voice to build public switched telephone network (PSTN) connectivity solutions. For example, you can programmatically connect to the PSTN to make calls and use AI to analyze and extract insights from conversations.

## Evaluate

Evaluate Twilio features and products that support PSTN connectivity to determine which ones are right for your needs.

#### CLICK TO EXPAND

* **[Voice Insights](/docs/voice/voice-insights)**: Monitor and analyze call events, call quality, and more.
* **[Conversation Intelligence (classic)](/docs/conversation-intelligence-classic)**: Use AI to analyze and extract insights from customer conversations.
* **[Caller ID Name (CNAM)](/docs/voice/brand-your-calls-using-cnam)**: Display your business name on recipients' mobile phones or landlines.

### Advanced connectivity and event streaming

* **[SIP for Programmable Voice](/docs/voice/api/sip-interface)**: Use your existing SIP communications infrastructure with Twilio.
* **[Bring Your Own Carrier (BYOC) Trunking](/docs/voice/bring-your-own-carrier-byoc)**: Connect your own carrier and phone numbers to the Twilio platform for voice calls.
* **[Event Streams](/docs/events)**: Get a unified event stream and have it piped directly into your data infrastructure.

## Plan and build

Learn how to plan and build standalone, functional Twilio Programmable Voice components. Combine components to create a PSTN connectivity solution.

* **[Record calls](/docs/voice/tutorials/how-to-record-phone-calls)**: Capture audio from calls for quality assurance or compliance.
  * [Record single side of a call](/docs/voice/tutorials/how-record-single-side-call).
* **[Voice Recording settings](/docs/voice/recording-settings)**: Configure account-wide settings for voice recordings, including external storage and encryption.
* **[Voice recording encryption](/docs/voice/tutorials/voice-recording-encryption)**: Encrypt your voice recordings with your own public key for additional security.
* **[Failover Best Practices](/docs/voice/twilio-voice-failover-best-practices)**: Ensure your call center remains operational during outages.
* **[Emergency Calling](/docs/voice/tutorials/emergency-calling-for-programmable-voice)**: Connect callers to emergency services.
  * [Emergency Calling for SIP Interfaces](/docs/voice/sip/emergency-calling).
* **[Set up Media Streams](/docs/voice/media-streams)**: Use your own infrastructure for transcription and analysis.
  * [Media Streams WebSocket messages](/docs/voice/media-streams/websocket-messages).
  * [Consume a real-time Media Stream](/docs/voice/tutorials/consume-real-time-media-stream-using-websockets-python-and-flask): Learn how to consume a real-time Media Stream using WebSockets, Python, and Flask.
* **[Share information between your applications](/docs/voice/how-share-information-between-your-applications)**: Pass metadata between your backend and client-side applications using custom parameters at call connection time.

#### Trusted calling

**Set up trusted calling**: Increase call transparency and trust by displaying your info on recipients' phones.

* [Caller ID Name (CNAM)](/docs/voice/brand-your-calls-using-cnam): Display your business name on recipients' mobile phones or landlines.

#### Advanced connectivity

**SIP for Programmable Voice**: Connect your SIP-enabled equipment to the Twilio platform for outbound calls.

#### CLICK TO EXPAND

* [Getting started with SIP](/docs/voice/sip/quickstart)
* [Route calls to your SIP network](/docs/voice/tutorials/how-to-route-calls-to-your-sip-network)
* [SIP and TwiML interaction](/docs/voice/api/sip-twiml)
* [Use a private SIPconnection with Twilio Interconnect](/docs/voice/api/sip-interconnect)
* [Encrypt SIP calls with Secure Media](/docs/voice/api/secure-media)
* [SIP security best practices](/docs/voice/api/sip-security)

## Troubleshoot

Troubleshoot issues with PSTN connectivity.

#### CLICK TO EXPAND

* [Voice Insights FAQs](/docs/voice/voice-insights/frequently-asked-questions)
* [Troubleshooting voice calls](/docs/voice/troubleshooting)
* [Invoice and call log discrepancies](/docs/voice/why-doesnt-my-invoice-match-what-i-pull-from-the-call-logs)

## Maintain

Maintain and monitor your app and calls.

#### CLICK TO EXPAND

### Basic

**Set up and interpret Voice Insights**: Monitor and analyze call events, call quality, and more.

* [Use the Call Insights dashboard](/docs/voice/voice-insights/call-insights-dashboard) for a comprehensive overview of your voice communications performance.
  * [Subaccounts Call Insights dashboard](/docs/voice/voice-insights/subaccount-call-insights-dashboard)
* [View the Call Summary](/docs/voice/voice-insights/call-summary) to view call metadata, connection parameters, and quality indicators for every call.

### Advanced

**Advanced Voice Insights**: Use advanced features to gain deeper insights into your voice communications.

* [Set up Event Streams for Call Insights](/docs/voice/voice-insights/event-streams/call-insights-events): Get a unified event stream and have it piped directly into your data infrastructure.
* Enable [Advanced Voice Insights features](/docs/voice/voice-insights/advanced-features) and the [Voice Insights Intelligent Discovery AI Assistant](/docs/voice/voice-insights/voice-insights-intelligent-discovery-ai-assistant) for more nuanced insights.

**Track usage, costs, and application health**: Monitor usage and costs in the Console, through the API, or with Datadog, and set up alarms for application errors.

* [Track usage, costs, and application health](/docs/voice/guides/track-usage-costs-health): Monitor usage and costs in the Console, through the API, or with Datadog, and set up alarms for application errors.