WTG100 series digital/media trunk gateway are compact, dedicated and feature-rich VoIP to E1 PRI gateway. Intelligently packaged in a stackable 1U chassis, it is designed to interface between TDM & IP networks in enterprises or small-scale carrier locations for cost-effective communication. The models of the Digital Trunk Gateways are WTG100-1, WTG100-2, WTG100-4, WTG100-8. They provide 1/2/4/8 lines of E1 ports respectively. For an Voice over IP based system it provides E1 PRI trunking. WTG100 Series E1 trunk gateway series is a collection of experiences and know-how accumulated in the enterprise and service provider markets, provides excellent services that meet the needs of customers that ask for high quality VoIP services. Also, this product provides better PRI gateway services due to the unique QoS algorithm by ensuring Quality of Service (QoS) for SIP, MGCP VoIP call control protocols, and better calling quality.