3CX TLS Setup

---

---

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 https://portal.voxtelesys.net/ soon but for now it requires a ticket with [email protected]

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!

---

Take note!

Incompatibility issues have been observed with custom FQDN's (non-3CX provided domains). Contact support for more information and a possible work-around.

---