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1 Introduction and Description
V.90 Support/Functions
V.90 is the ITU designation for what formerly was called V.pcm. V.90 replaces K56flex and other proprietary solutions for PCM connections.
•V.90/K56flex
•New downstream data rates
•Optional V.8bis sequence
•V.90 Mode Selection
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•Automatic adapting to digital loss and
•New V.90 rate result codes
Downstream Rates
Where K56flex provided rates of 32,000 to 56,000 in 2,000 bps increments, V.90 provides rates of 28,000 to 56,000 bps in increments of 1,333 bps.
Upstream Data Rates
Upstream V.90 data rates are 4800 to 33600 bps in 2400 bps increments.
Optional V.8bis Sequence
The V.8bis sequence that precedes K56flex connections is optional for V.90.
Auto-rate Speeds
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