The CONEXANTTM RP56LD, RP336LD, and RP144LD Modem Data Pump (MDP) families support data/fax modem, voice coding/decoding, optional full-duplex speakerphone, and optional AudioSpan (Table 1). Low voltage and low power consumption support portable applications. Downloadable architecture allows upgrading of MDP code from the host/DTE. In V.90/K56flex mode (RP56), the MDP can receive data at speeds up to 56 kbps from a digitally connected V.90or K56flex-compatible central site modem. These MDPs take advantage of the PSTN which is primarily digital except for the client modem to central office local loop and are ideal for applications such as remote access to an Internet service provider (ISP), on-line service, or corporate site. The MDP can send upstream data at speeds up to V.34 rates.