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1head - synchronous data compression (sdc) feature, 1head - automode/multimode feature, Synchronous data compression (sdc) feature – Motorola 326X V.34 User Manual

Page 31: Automode/multimode feature

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About the Modem 1-7

About the

Modem

Data Rate: 2.4, 4.8, 7.2, 9.6, 12.0, 14.4, 16.8, 19.2, 21.6, 24.0, 26.4, 28.8, 31.2, and
33.6 kbps

Baud Rate: 2400, 2743, 3000, 3200, and 3429. Some baud rates do not support all
data rates.

Carrier Frequency: 1600, 1646, 1800, 1829, 1920, 1959, and 2000 Hz. Some baud
rates do not support all carrier frequencies.

Modulation: V.34 is a four-dimensional trellis-coded modulation standard that uses
precoding and pre-emphasis equalization schemes.

Compatibility in V.34 Modulation Mode

326XFAST Series Modems (operating in V.34 Auto modulation mode), are
compatible with modems that do not support the V.34 modulation mode, by
automatically negotiating the highest common modulation mode (e.g., V.32bis).

V.90 Compatibility: Release 8.1 software enables 326X modems to operate with
V.90 modems in dial-up connections. With this software, 326X modems can commu-
nicate with V.90 modems and negotiate V.34 rates. The release does not provide
56kbps rates for 326X modems, nor 326X rates higher than the V.34 33.6 kbps stan-
dard. An upgrade to 8.1 is not required for modems used only in leased-line applica-
tions.

Synchronous Data Compression (SDC) Feature

The 326XFAST Series Modem is available in a synchronous data compression
(SDC) model. 326XFAST products offer all the features of the 326XFAST family,
plus synchronous DTE rates at 72.0 kbps or higher.

The 326XFAST-SDC Modem is an ideal alternative to costly digital services.
Whether your application requires dedicated bandwidth, bandwidth on demand,
synchronous dial-up, or dial backup, the 326X-SDC provides optimum throughput
for all HDLC/SDLC-like environments, such as X.25, Systems Networking
Architecture (SNA), Statistical Multiplexer, and Router networks.

Refer to Chapter 4, Configuring the Modem, for details.

The synchronous data compression feature in the 326XFAST-SDC Modem is
Motorola proprietary technology.

Automode/Multimode Feature

Using Automode/Multimode, the modem can automatically negotiate the highest
common modulation speed (within a modulation mode) with another modem.