Multiport T1 ATM network modules with Inverse Multiplexing over ATM (IMA) allow service provider and enterprise customers to cost-effectively increase bandwidth, extending multiservice capabilities to remote-branch-office locations through ATM.These multiport T1 ATM network modules with IMA add to the broad Cisco portfolio of customer premises equipment (CPE), ATM edge, and central-office products, that allow branch offices to take advantage of the higher bandwidth and multiservice capabilities available from ATM services.Multiport T1 IMA network modules functionality allows access to ATM WAN uplinks with bandwidth requirements between DS1 and DS3 rates. All multiport ATM network modules support the ATM Forum Adaptation Layer 5 (AAL5) with ATM QoS categories Unspecified Bit Rate (UBR), Variable Bit Rate (VBR-rt and VBR-nrt), and Available Bit Rate (ABR). VoIP and H.323 video over ATM can be supported using VBR-rt class of service (CoS) parameters with the currently available analog voice/fax network modules with voice interface cards (VICs), or the new T1 digital packet voice trunk network modules with multiflex trunk cards.The multiport T1 IMA modules' support for VoIP and H.323 video applications provides low latency, jitter-free voice support to enhance throughput, and high-quality, end-to-end voice and video performance. When combined with high-density packet telephony solutions already available on the Cisco 2600 and 3600 series, the multiport ATM network modules provide a seamless end-to-end multiservice solution, interoperable with other ATM Forum IMA version 1.0 products available from Cisco.