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Inbound Call Screening

Protect your business from unwanted spam calls with Inbound Call Screening.

Telnyx Engineering avatar
Written by Telnyx Engineering
Updated over a week ago

At Telnyx, we are committed to providing you with robust features to enhance your communication experience. We're excited to introduce Inbound Call Screening, a powerful feature designed to protect Telnyx numbers from unwanted and spam calls.

Inbound Call Screening, enables users to flag and block unwanted incoming calls based on customizable conditions to maintain the integrity of their communications.

Inbound Call Screening features include:

  1. Enhanced Call Control: Users can now reject or flag suspicious calls based on customizable conditions—empowering businesses to manage incoming calls with confidence.

  2. Spam Call Detection: Effectively screen and identify potential spam calls to protect Telnyx numbers from unwanted solicitations and fraudulent activities, and avoid spam calls.

How do I configure Inbound Call screening?

  1. Login to your Telnyx Mission Control Portal account.

    1. Navigate to the "My Numbers" section on the left-hand sidebar in the portal.

    2. From the list of your numbers, choose the Telnyx number you want to configure Inbound Call Screening on.

      My numbers section of the mission control portal.
  2. Enable call screening for the selected number

    1. By choosing the desired action for calls that match the conditions.

      Call screening section.
    2. Define the conditions for call screening.

      Call screening section.
  3. Save your call screening settings.

Keep reading to learn more about how inbound call screening works.

How much does Inbound Call Screening cost?

The cost for configuring Inbound Call Screening on a given number is dependent on the total amount of numbers with the feature configured. Tiered pricing is as follows:

  • 0-50 numbers = $1.00 per number per month

  • 51-250 numbers = $0.75 per number per month

  • 251+ numbers = $0.50 per number per month

Inbound Call Screening FAQs

How does Inbound Call Screening work?

There are 2 factors that we use to implement inbound call screening—Number Reputation Database and SHAKEN/STIR Attestation.

Number Reputation Database

Inbound Call Screening leverages a comprehensive number reputation database to assess the reputation score associated with incoming calls' Calling Line Identity (CLI).

Telnyx aggregates data from multiple sources to define the reputation of a number and uses that information to classify callers as potential spammers.

SHAKEN/STIR attestation

Inbound Call Screening employs the SHAKEN/STIR attestation protocol to validate the authenticity of Caller ID information to help ensure the legitimacy of incoming calls.

Inbound Call Screening will be applied to the following attestation levels:

  • Attestation C - This is when the originating carrier cannot authenticate the Caller ID or the Caller ID has been identified as invalid.
    Calls with C attestation are potentially suspicious and are subjected to Inbound Call Screening.

  • Attestation Invalid - This is when the SHAKEN/STIR attestation for a call is deemed invalid—possibly due to certificate problems or technical errors—and indicates a potential risk of spam or fraud.

How can I treat unwanted inbound calls?

Telnyx users can handle unwanted calls in 2 ways.

Reject calls

By selecting the Reject option, suspicious calls as defined by the above criteria, will be rejected.
This ensures that calls identified as potentially unwanted or spam are not connected to your Telnyx number.

Flag calls

By selecting the Flag option, you can flag suspicious calls that match the defined conditions. Flagged calls receive clear indications to help you identify them easily.

The name part of the From and P-Asserted-ID headers will display the text "SPAM LIKELY," providing a visual indicator of the flagged call. In addition, a custom SIP header, "X-Telnyx-Call-Screening: SPAM LIKELY," will be added to the SIP INVITE message, to highlight the call status.

If you have webhooks enabled, the call.initiated webhook will include the variable "call_screening_result" with the value "spam_likely", providing detailed information about the call screening outcome.

What are the benefits of using Inbound Call Screening?

Inbound Call Screening allows you to avoid spam calls by effectively screening and identifying potential spam callers and gives you enhanced call control, allowing you to reject or flag suspicious calls based on customizable conditions.

Where is Inbound Call Screening available?

Inbound Call Screening currently applies to calls originating from the United States or Canada for number reputation screening. SHAKEN/STIR attestation screening is applicable to calls from North America.

Are there any additional requirements to make the most of Inbound Call Screening?

To maximize the benefits of Inbound Call Screening, ensure that you have webhooks enabled.

You can specify webhook urls on your SIP Connection settings or through your programmable voice applications.

Webhooks provide real-time notifications and detailed insights into the call screening process and outcomes. Enabling webhooks will include the "call_screening_result" variable in the call.initiated webhook, providing detailed information about the call screening outcome.

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