CDM-600 Satellite Modem Revision 7
Clock Modes and Drop and Insert (D&I) MN/CDM600.IOM
10–6
10.4 Drop and Insert
The Drop and Insert (D&I) multiplexer works in conjunction with the G.703 interfaces to
enable the modem to transmit or receive fractional parts of a T1 or E1 data stream.
The D&I option provides fully compliant baseband processing in accordance with
Intelsat IESS-309 for the terrestrial information rate of 2048 kbps (E1) and 1544 kbps
(T1), using G.703 interfaces. The data rate sent over the satellite link is n x 64 kbps. See
the Frame Formats diagram for the permissible values of n. The modem provides the
interface to transmission level framing compliant to IESS-309 data type 2.
Notes:
1. For Hardware Version 2.0 or higher, Firmware Version 1.3.1 or higher, D&I
operation is possible through the 25-pin data port in either RS-422 or V.35
format. If used, the DDO/IDI ‘inner loop’ is not available.
2. For Firmware Version 1.5.0 or higher, D&I operation can also be done using the
proprietary D&I++ framing mode.