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Custom SIP Trunks

Custom SIP trunks allow you to import your own phone numbers to Diga, maintaining full control over your telephony infrastructure while leveraging the capabilities of intelligent voice agents.

Overview

What is a SIP Trunk?

A SIP trunk is an IP telephony connection that allows you to make and receive calls using the SIP (Session Initiation Protocol) protocol. With custom SIP trunks, you can:
  • Import existing numbers: Bring your current numbers to Diga
  • Keep your provider: Continue working with your current operator
  • No additional billing: Diga does not charge for custom numbers
  • Full control: Manage your SIP configuration

Prerequisites

Before importing a custom number, make sure you have:
1

Number in E.164 format

Your number must be in international E.164 format (e.g.: +34912345678)
2

Configured SIP provider

You need an active SIP provider that supports:
  • Inbound calls
  • Outbound calls
3

SIP credentials

Obtain from your provider:
  • SIP username
  • SIP password
  • Termination URI
If you don’t have a SIP provider or are not familiar with technical configuration, consider buying phone numbers on the platform for a simplified experience.

Import a Custom Number

Required SIP Information

SIP Username

Your user identifier provided by the SIP provider. Example: user123 or my-company

SIP Password

The password to authenticate calls with your provider.
Save this password securely. Diga stores it encrypted but you must keep it confidential.

Termination URI

The address of your provider’s SIP server where calls will be sent. Typical format: sip:[domain]:[port] Examples:
  • sip:sip.myprovider.com:5060
  • sip:trunk.example.net:5061
If you are unsure of these values, contact your SIP provider. This information is usually available in your SIP service control panel.

Managing Custom Numbers

View Custom Numbers

Custom numbers appear in your number list along with Diga numbers, but are clearly identified in the provider column as “Custom”.

Delete a Custom Number

Unlike Diga numbers, custom numbers can be deleted immediately without a quarantine period.

Billing

No Charges in Diga

Custom numbers do not generate charges on your Diga invoice:
  • No monthly fee per number
  • No setup charges
  • No call charges (you pay directly to your SIP provider)

Costs with your SIP Provider

Your SIP provider may charge you for:
  • Monthly number rental
  • Inbound calls
  • Outbound calls
  • SIP trunk configuration
Review billing terms directly with your SIP provider, as Diga does not manage these payments.

Minutes Usage

Calls made with custom numbers do consume minutes from your Diga plan:
  • Minutes count the same as with Netelip numbers
  • Applied to your monthly minute allocation
  • If you exceed your plan, additional minutes are charged (if enabled)
Only the number itself is free in Diga. Call time still consumes your minutes included in your subscription plan.

Troubleshooting

Inbound calls don’t work

Possible causes:
  1. Incorrect SIP credentials
  2. Misconfigured termination URI
  3. Your SIP provider is not forwarding calls to Diga
  4. No agent assigned for inbound calls
Solutions:
  • Verify credentials with your SIP provider
  • Ensure the termination URI is correct
  • Contact your provider to verify forwarding
  • Assign an agent for inbound calls

Outbound calls fail

Possible causes:
  1. Your SIP provider does not allow outbound calls
  2. Incorrect credentials
  3. Provider restrictions (allowed destinations, limits, etc.)
  4. No agent assigned for outbound calls
Solutions:
  • Verify that your SIP trunk supports outbound calls
  • Confirm credentials with your provider
  • Review your provider’s outbound call policies
  • Assign an agent for outbound calls

Error importing the number

Possible causes:
  1. Incorrect number format (not E.164)
  2. The number is already imported in another project
  3. Invalid SIP credentials
Solutions:
  • Make sure to use E.164 format with + at the beginning
  • Verify that the number is not in use in another project
  • Confirm that the credentials are correct

Poor call quality

Possible causes:
  1. Issues with your SIP provider
  2. Network latency
  3. Incompatible codec configuration
Solutions:
  • Contact your SIP provider to verify quality
  • Verify network connectivity
  • Consult with your provider about supported codecs
Diga has no control over the quality of custom number calls. If you experience persistent issues, contact your SIP provider.