The MultiVOIP® FX SIP gateway provides toll-free voice and fax communications over the Internet or Intranet. Available in 2-, 4-, and 8-port models, the MultiVOIP FX gateway connects directly to phones, fax machines, key systems, PSTN lines, or a PBX to provide real-time, toll-quality voice connections to any office on your VOIP network. The MultiVOIP FX gateway is designed to maximize the investments you've already made in your data and voice network infrastructure.