SIP extensions

Documentation Index

Fetch the complete documentation index at: https://docs.astradial.com/llms.txt

Use this file to discover all available pages before exploring further.

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What is a SIP extension?

A SIP extension is a short number (like 1001, 1002, 1003) that identifies a person or device in your phone system. When someone calls extension 1001, it rings the phone app registered to that extension. SIP stands for Session Initiation Protocol. It is the standard technology that makes internet phone calls work. When you register a SIP app (like Zoiper) with your extension credentials, your device connects to the Astradial server and can make and receive calls.

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How extensions are assigned

When you create a user, you give them an extension number. Astradial then:

1. Creates a SIP endpoint on the Asterisk PBX server
2. Generates a unique SIP password
3. Deploys the configuration so calls to that extension number are routed correctly

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Extension number conventions

You can use any number for extensions, but here are common patterns:

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Connecting a SIP phone

You can use any SIP-compatible phone app or hardware phone. Here are the most popular options:

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Software phones (free)

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Hardware phones

Any SIP-compatible desk phone works with Astradial. Popular brands include:

• Yealink
• Grandstream
• Polycom
• Cisco SPA series

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Registration settings

When configuring a SIP phone manually, use these settings:

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Making your first call

Once your SIP phone is registered:

1. Call another extension — Dial the extension number (like 1002) to call a colleague
2. Call an external number — Dial the full phone number (with country code if needed). This requires an outbound trunk to be configured.
3. Receive a call — When someone calls your phone number (DID) and it is routed to your extension, your phone will ring

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Troubleshooting