USRobotics V.34 - Manual (Page 14)

COURIER HIGH SPEED MODEMS
1-2 Features and Compatibility
Universal Connect
Courier high speed modems automatically detect and connect
at the fastest available speed.
Adaptive Speed Leveling (ASL)
Like most high speed modems, Courier modems fall back to the
next lower speed—for example, 19.2K, then 16.8K in V.
terbo
mode—if poor line conditions warrant. In addition, Courier
V.32
bis, and V.32 terbo modems detect improved line conditions
and shift upward again to the next higher speed. both transmit
and receive channels adapt independently, each detecting and
adjusting to line conditions. ASL keeps the modems online,
always operating at the highest possible speed, and constantly
ensuring data integrity.
Fax Capability
You can use your modem with Class 1 or Class 2.0 facsimile
software to exchange faxes with millions of Group III fax
machines worldwide. See Chapter 5.
Error Control

V.42/MNP
Data integrity is ensured when the modems connect with
remote modems that use the V.42 (LAPM), HST, or MNP error
control protocols. Error control is available on calls at 1200 bps
and above.
Data Compression

V.42 bis/MNP5
Data compression enables potential throughput of up to 115.2K
bps on 28.8K bps connections. Couriers connecting under V.42
or HST error control use V.42
bis compression. Couriers
connecting under MNP error control use MNP Level 5
compression. Typical throughput of text and other types of files
using V.42
bis is provided in Appendix A.