AudioCodes MediaPack 204B Analog VoIP Gateway – 4-Port FXS, SIP & T.38 Fax for Analog Phone Connectivity (MP204B/4S/SIP)

The AudioCodes MediaPack 204B (MP204B/4S/SIP) is a compact 4-port FXS analog VoIP gateway that connects standard analog phones, fax machines, and analog devices to SIP-based IP telephony networks. Supporting SIP and T.38 fax relay, it enables seamless integration of legacy analog endpoints into modern VoIP infrastructure without replacing the devices themselves. With four independent FXS ports, it is sized for branch offices, small businesses, and departmental deployments where a small number of analog devices need SIP connectivity.

The Telecom Spot Take

The MediaPack 204B occupies a sweet spot for organizations with a handful of analog devices that need to survive a SIP migration. Rather than replacing a working fax machine, an analog conference room speakerphone, or a dedicated analog emergency line, you connect them to the 204B and they register on the SIP platform just like any IP phone. Four ports cover a typical branch or small office analog requirement — a front desk phone, a fax machine, a conference room analog unit, and an emergency line. SIP compatibility is broad, and T.38 ensures fax reliability over IP. For larger analog requirements, the MediaPack 124 (24 ports) is the natural step up.

Key Features

• 4 FXS analog ports — connect up to 4 analog phones, fax machines, or analog devices to SIP
• SIP protocol support — full SIP interoperability with IP PBX, hosted UC, and Teams/Zoom platforms
• T.38 fax relay — reliable fax transmission over IP without hardware fax replacement
• Compact form factor — desktop or wall-mount deployment for branch and SMB environments
• Preserve existing analog investments — extend analog device lifespan on new SIP infrastructure

Technical Specifications