Connecting Siperb to Your PBX

Connecting Siperb to Your PBX

A Connection is how Siperb knows how to reach your PBX and route calls. This guide explains what connections are, why you need them, and which type to choose.

What Is a Connection?

A Connection is a configuration that tells Siperb:

  • Where your PBX is located (its address and port)
  • How to authenticate with your PBX (credentials)
  • Which calls should be routed through this connection (dial patterns)
  • How your PBX expects to communicate with Siperb (registration, trunk, etc.)

You create connections in your Admin Control Panel under Connections.

Do You Need a Connection?

If you’re using WebSocket mode (free): No. WebSocket mode connects directly from your phone to your PBX. No connection needed.

If you’re using Proxy mode (paid): Yes. You must create at least one connection so Siperb’s proxy knows how to reach your PBX.

Learn the difference: Registration Modes: Which One is Right for You?

Three Types of Connections

Choose the type that matches how your PBX is set up.

1. Outbound Registration

Siperb registers with your PBX on behalf of your users. Your PBX sees Siperb as an extension or trunk.

When to use: Most organisations. This is the default.

Works with: Asterisk, FreeSWITCH, 3CX, Avaya, Sangoma, and most SIP-compatible PBXs.

What you need:

  • Your PBX’s SIP registration address (e.g., pbx.example.com or 203.0.113.50)
  • SIP username and password for Siperb to register with
  • Dial patterns that tell your PBX which calls to send to Siperb

How it works: Siperb connects to your PBX and “registers” like a phone extension would. Your PBX then knows to send certain calls to Siperb, which routes them to the appropriate user.

Full guide: Outbound Registration Connections

2. Outbound Trunk

Siperb sends calls to a static IP on your PBX. No registration — Siperb just opens a connection and starts sending SIP messages.

When to use: Carriers, ITSPs, or when your PBX can’t accept inbound registrations. Also used for large deployments where you want explicit control over traffic routing.

What you need:

  • Your PBX’s static IP address and port
  • Optional: SIP credentials if your PBX requires authentication
  • Dial patterns for routing

How it works: Siperb opens a TCP or UDP connection to your PBX’s fixed IP and sends SIP INVITE messages directly. No registration handshake — simpler and lower-latency, but requires a dedicated IP.

Full guide: Outbound Trunk Connections

3. Inbound Registration

Your PBX registers with Siperb instead of the other way round. Siperb acts like a registrar (like a PBX would normally).

When to use: Your PBX is behind NAT, a firewall, or can’t accept inbound connections. Your PBX can reach Siperb, but Siperb can’t reach your PBX.

What you need:

  • Your PBX’s outbound connection capability (most PBXs have this)
  • SIP credentials we provide for your PBX to register with
  • Dial patterns to identify calls meant for your domain

How it works: Your PBX initiates a connection to siperb.com and “registers” with Siperb. When a call comes in for your domain, Siperb forwards it back through that persistent connection. Elegant for distributed or remote PBXs.

Full guide: Inbound Registration Connections

Dial Patterns

Every connection has one or more dial patterns — rules that tell Siperb which numbers should be routed through this connection.

Examples:

  • 4[0-9]{3} — Any extension starting with 4 (4000–4999). Send to this PBX.
  • ^0[0-9]{9,10}$ — UK geographic numbers. Route to your trunk.
  • .* — Any number. Default catch-all.

If you have multiple connections, Siperb tries them in order until one matches the dialled number.

Multiple Connections

You can create several connections. Common scenarios:

  • Failover: Two outbound registrations pointing to the same PBX (hot standby)
  • Multi-site: One connection for each branch office PBX
  • Hybrid: Outbound registration for internal calls, outbound trunk for a carrier connection

Dial patterns determine which connection handles each call.

Creating a Connection

  1. Sign in to siperb.com/phone/
  2. Click Admin (top right)
  3. Go to Connections
  4. Click Add Connection
  5. Choose your connection type
  6. Enter your PBX details (address, credentials, dial patterns)
  7. Click Test Connection — Siperb will verify it can reach your PBX
  8. Click Save

For step-by-step instructions for each type, see:

Troubleshooting Connections

Connection test fails.

Check:

  • Your PBX is online and reachable from the internet
  • The address and port are correct
  • Firewall rules allow Siperb’s IP ranges (contact support for a list)
  • Credentials are correct
  • SIP TLS is properly configured (if using TLS)

Connection succeeds, but calls don’t route.

Check your dial patterns. They must match the numbers you’re dialling. Test with a simple pattern like .* first.

My PBX was reachable before, now it’s not.

This usually means your PBX has lost internet access or its IP address has changed. Update the connection with the new address or contact your network admin.

Next Steps