Communications & VPN TLS/SSL Guides

Secure VoIP signaling, remote access, and VPN tunnels with modern cryptography. These guides cover TLS transport for SIP, SSH hardening, and IKEv2/IPsec configuration.

Asterisk

Open-source PBX and communications platform.

FreeSWITCH

Scalable open-source telephony platform.

Kamailio

High-performance SIP server and proxy.

OpenSSH

Secure remote access and file transfer.

OpenVPN

Full-featured open-source VPN solution.

strongSwan

IPsec VPN with IKEv2 and certificate auth.

About These Guides

Communications infrastructure handles authentication credentials and often carries sensitive conversations. VoIP platforms using unencrypted SIP are trivially interceptable. SSH servers accepting weak key exchange algorithms or password authentication are common targets for brute-force attacks.

These guides go beyond basic TLS configuration to address the full cryptographic posture: cipher suites, key exchange algorithms, authentication methods, and protocol-specific hardening for each platform.