VoIP Capabilities: The S20 supports VoIP technology, allowing users to make and receive calls over an IP network instead of traditional phone lines. This helps reduce costs and enables more flexible communication options.

SIP and IAX2 Protocol Support: The S20 supports Session Initiation Protocol (SIP) and Inter-Asterisk eXchange (IAX2) protocols, which are widely used in VoIP communications. This ensures compatibility with a wide range of VoIP service providers and devices.

FXS and FXO Ports: The S20 features FXS (Foreign Exchange Station) ports for connecting analog phones or fax machines and FXO (Foreign Exchange Office) ports for connecting to traditional PSTN (Public Switched Telephone Network) lines. This allows users to integrate existing analog devices or connect to the PSTN network if needed.

Call Routing and Forwarding: The S20 supports various call routing and forwarding features, including call transfer, call waiting, call hold, call forwarding, and more. These features ensure efficient call management and improve overall communication capabilities.

Voicemail and Auto Attendant: The S20 includes voicemail functionality, allowing callers to leave messages when users are unavailable. It also supports an auto attendant feature, which provides a customizable automated greeting and menu options to guide callers to the appropriate extension or department.

Call Recording: The S20 allows for call recording, which can be useful for quality assurance, training, or legal purposes. Recording files can be stored on an SD card or USB flash drive.

Web-based Management Interface: The S20 can be configured and managed through a web-based interface, providing an intuitive and user-friendly management experience. This interface allows administrators to set up extensions, configure call routing rules, manage voicemail, and access various system settings.