DESC: The Dialogic Dual Span Series of digital voice and network interface boards provide two E-1 or T-1 ISDN Primary Rate Interface (PRI) lines of service termination and call processing for 30 or 60 voice channels (E-1 boards) or 24 or 48 channels (T-1 boards) in a single PC slot. Functionally, the Dual Span boards are equivalent to two single-span boards, combined into one single-slot ISA board. A unique multiprocessor architecture comprising digital signal processors (DSPs) and general-purpose microprocessors handles all telephony signaling and performs all DTMF, MF, and audio/voice signal processing tasks. Downloaded firmware algorithms, Spring Ware, executed by the on-board DSPs, provide variable voice coding at 24 and 32 Kb/s adaptive differential pulse code modulation (ADPCM), and 48 and 64 Kb/s µ-law or A-law pulse code modulation (PCM). ??Sampling rates and coding methods are selectable on a channel-by-channel basis. Applications can dynamically switch sampling rate and coding ...