Comtech EF Data SDM-300A - Manual (Page 262)

SDM-300A Satellite Modem Revision 6
Open Network Operations MN/SDM300A.IOM
10–6
10.2.3 IBS Primary Data Interfaces
• Accepts and outputs primary data through the 50-pin connector using G.703. The
data rate is T1 or E1 rates only.
• Accepts and outputs primary data through the 50-pin connector using EIA-422.
The data rate is at multiples of 64 kbps up to a maximum of 2048 kbps.
• Accepts and outputs primary data through the 50-pin connector using V.35. The
data rate is at multiples of 64 kbps up to a maximum of 2048 kbps.
10.2.4 IBS Clock and Dejitter
Performs clock and data recovery on the G.703 format. Clock dejitter and data
encoding/decoding is done as with the IDR configuration.
10.2.5 IBS Framing
Multiplexes/demultiplexes the primary data in compliance with the standard IESS-309
overhead ratio of 1/15 (4 overhead bytes per 60 data bytes) and provides the rate
exchanged transmit clock to the modulator portion of the base modem.
10.2.6 IBS Engineering Service Channel
Bi-directional processing of the components of the ESC channel, including the
asynchronous or synchronous EIA-232 data channel, and fault/alarm indications.
10.2.7 IBS Scrambling
Provides the synchronous scrambling/descrambling of the satellite framed data specified
in IESS-309. Base modem scrambling/descrambling is assumed to be disabled in this
mode.