The Cisco 3600 Series is a family of modular, multiservice access platforms for medium and large-sized offices and smaller Internet Service Providers. With over 70 modular interface options, the Cisco 3600 family provides solutions for data, voice video, hybrid dial access, virtual private networks (VPNs), and multiprotocol data routing. The high-performance, modular architecture protects customers\' investment in network technology and integrates the functions of several devices into a single, manageable solution. Cisco extended the successful Cisco 3600 Series with the Cisco 3660 multiservice access platform. The Cisco 3660 provides higher densities, greater performance, and more expansion capabilities. The additional power and performance of the Cisco 3660 platform enables new applications, such as packetized voice aggregation and branch office ATM access ranging from T1/E1 IMA to OC-3. The Cisco 2600 and 3600 series of multiservice platforms has been greatly enhanced with many voice capabilities: added support for Voice over Frame relay (VoFR) and Voice over ATM (VoATM-AALS) on the digital voice interfaces (T1 and E1). QSIG is also now supported on all digital interfaces, including T1/E1 and BRI. Other enhancements include Off Premise Extension (OPX), VoIP over Frame Relay, and enhanced queueing functionality. In addition, a feature that works with an upcoming version of Call Manager softwars makes these products perfect gateways for the PBX and PSTN for IP telephony, enabling applications like call transfers, holds, and conferencing.