Preparing TLS Certificates

Please take the steps listed below to get trusted certificates.

  1. Purchase a Domain (for example, from the domain provider (for example, Godaddy.) for your PBX and SBC.

  2. Add an A record in the Domain DNS zone, and resolve the Domain to your PBX IP, for example: point the to PBX server IP.

  3. If your SBC is deployed separately from the PBX server, add an A record DNS record and resolve to the SBC server IP, for example, point point to the SBC server IP.

  4. Purchase a TLS certificate from the trust certificate provider for your domain, for example, Digicert, Thawte, GeoTrust; If your SBC is deployed separately from the PBX server, you must purchase the Wildcard Certificate.

  5. Generate the CSR file and private key file according to the certificate provider’s guide, and keep the files. Please don't set the password when generating the private key file; usually, you will have two files: the certificate and the private key. Note: Please choose the certificate type for Nginx.

  6. Rename the private key file as portsip.key.

  7. Submit the CRS file to the certificate provider, and download the certificate files after your certificates are approved. This step will end up with two files: Intermediate CA certificate and TLS certificate . Assume the file names are:

    • The TLS certificate file: cert.pem

    • The Intermediate CA certificate file: intermediate.pem

    Note that some providers don't have the Intermediate CA certificate.

  8. Please ignore this step if your provider doesn't provide the Intermediate CA certificate . Use a plain text editor for example Windows Notepad (do not use MS Word) to open the Intermediate CA file and TLS certificate file, copy the Intermediate CA contents to append to the TLS certificate file, and rename the TLS certificate file as portsip.pem. In the Linux environment, you can use the below commands to combine the certificate files.

// Append intermediate file to TLS certificate file
cat intermediate.pem >> cert.pem
  1. Rename the certificate file:

// Rename certificate file to portsip.pem
mv cert.pem portsip.pem
  1. Now you will have two certificate files:

  • Certificate File: portsip.pem,

  • Private Key file: portsip.key

Now please follow the article Update Certificates to update the certificates.

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