3CX TLS Setup

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1. Contact Voxtelesys

You will need to reach out to Voxtelesys and schedule a time to move your trunk to TLS/SRTP, this feature will be coming to the Portal soon but for now it requires a ticket with support@voxtelesys.com

2. Verify your Voxtelesys Domain on your 3CX

Open your Voxtelesys SIP trunk and ensure that your Registrar/Server/Gateway Hostname or IP is set to 3cx.pstn.voxtelesys.net

If you have a unique domain name like xxxxxx-xxxx.sip.voxtelesys.net then reach out to support and request a new registration domain.

3. 3CX Trunk Updates

Go to Options and change the following settings:

SRTP Mode = Enabled

Transport Protocol = TLS

Before saving the trunk settings we will need to upload the root certificate for the domain.

4. Download the Root Certificate

Go to https://letsencrypt.org/certificates and download the Active "PEM" certificate.

5. Load Cert into 3CX

Go back to the 3CX and upload the certificate under options > Transport Protocol = TLS > Click "Upload"

You should now see an expiration date.

Save the Trunk settings

6. Verify with Voxtelesys

Let Voxtelesys support know that the TLS/SRTP is in place on the 3CX trunk and support will verify the correct settings are enabled on your trunks!

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