Comtech EF Data CDM-760 - Manual (Page 108)

Front Panel Operation Revision 2
CDM-760 Advanced High-Speed Trunking Modem MN-CDM760
6–22
1) If you are in MultiStream Mode, the buffer depth is calculated using only the
Ethernet data rate – not the aggregate data rate.
2) The WAN Buffer is a FIFO (First In First Out) buffer, not a circular buffer. This
means that, as long as the Ethernet ingress to the modem does not exceed the
Ethernet Data Rate of the modem, the buffer will always remain relatively
empty and there will be NO ADDED LATENCY. The buffer will begin to fill and
you will experience added latency only when the Ethernet traffic ingress to the
modem exceeds the egress of the Ethernet data rate.
3) By enabling Flow Control, the modem begins to send Pause Frames to any
device connected to the Ethernet Data Interfaces at approximately 87%
capacity. Pause Frames cease to be sent to the Ethernet Interfaces when the
WAN Buffer Full Status drops below 75% capacity. See (CONFIG: INTF)(GBEIX)
FlowControl in Sect. 6.2.2.4.2 for more information about Flow Control.
6.2.2.3 (CONFIG:) Rx
Rx: Mod Data Freq EsNo
Data 155520.000kbps 060140.976ksps ()
On the top line – Use the   arrow keys to select a parameter. Press ENTER.
The read-only bottom line shows the operating data rate (in kbps) and symbol rate (in ksps).
The Data rate displays “00000.000kbps” when the demodulator is unlocked.
6.2.2.3.1 (CONFIG: Rx) Mod
This screen displays “Demodulator Is Not Locked” if the demodulator is unlocked.
ModCod=8PSK 8/9 Frame:Normal
Pilots:On ()
This read-only screen identifies the active modulation type, coding, Framing Mode, and Pilot
setting.