Comtech EF Data CDM-700 - Manual (Page 37)

CDM-700 High Speed Satellite Modem Revision 5
Functional Description MN/CDM700.IOM
3.2 Interfaces Modules
The two interface slots and multi-port interfaces provide a simple way to use standard telecom
interfaces and to fill the gap in standard data rates between 52 and 155 Mbps by multiplexing data
streams together. The standard telecom interfaces are G.703, E3, T3, STS-1 and HSSI at the
lower end, and STM-1 or OC-3 at the top end, with a large unserved range between the two ends.
Module Description Mbps
CDI-10 Dual E3 / T3 / STS-1 G.703 Data Interface 34.368 / 44.736 / 55.184
CDI-50-1 OC-3 / STM-1 Single Mode and G.703 Coaxial Interface 155.52 (Fixed)
CDI-60 HSSI Interface 1.5 to 70
CDI-70 1000 Base-T Gigabit Ethernet Interface (GbEI) 1.5 to 155.52
Figure 3-1. CDM-700 Modem Block Diagram
Operating with multiple interfaces allows greater efficiency:
•
The transponder operates with less backoff and at higher efficiency with a single-carrier
and this translates into higher throughput.
•
Operating with a single carrier requires fewer modems than operating with multiple
carriers. The impact of one versus multiple modems in many applications is less of an
impact than the monthly transponder expense, but it is part of the overall ease of
operation.
For additional information see the applicable section in the manual for each interface.
3–3