Keep legacy analog devices in service while you transition voice infrastructure to SIP. The AudioCodes MediaPack 5xx analog VoIP gateway with 4 FXS voice interfaces is designed for environments that need to protect existing phone investments without delaying modernization. It provides a straightforward bridge between analog endpoints and IP telephony, helping maintain service continuity across branch offices, small sites, and staged migration projects. With four FXS ports, this model supports a focused deployment footprint for a limited set of analog phones or other voice devices. Redirect service adds another layer of operational control, helping preserve call flow during routing changes or network events. That matters when the goal is not just connectivity, but predictable behavior in production voice environments. For IT teams managing mixed telephony estates, the MP504/4S/SIP/RS offers a clean path to reduce disruption, extend the life of analog assets, and align voice services with SIP-based infrastructure. It is the kind of gateway chosen when reliability, compatibility, and migration discipline are more important than excess port count.