Comtech EF Data CDM-625A Installation And Operation Manual page 672

CDM-625A Advanced Satellite Modem
Appendix R
QUESTION: What is the total output data rate and what is individual ports output data rate?
ANSWER:
•
Based on Table 20-1 for a modem Tx bandwidth of 1 Mbps, the QoS output bandwidth is set
to 1 Mbps.
•
Total Input data rate is 4X 250 Kbps = 1 Mbps
•
The output Data rate = 1 Mbps
•
Each ports data rate = 250 Kbps
QoS Example 3
• Port-based Layer 2 QoS mode is selected.
•
Port Layer 2 QoS Priorities are set as follows:
o Port 1 priority is set to 1;
o Port 2 priority is set to 2;
o Port 3 priority is set to 3;
o Port 4 priority is set to 4.
•
The modem data rate is set to 2500 Kbps.
•
The ingress traffic on Ports 1 and 2 are set to 2 Mbps.
•
The ingress traffic on Port 3 is set to 800 Kbps.
•
The ingress traffic on Port 4 is set to 500 Kbps.
QUESTION: What is the total output data rate and what are the individual port output data
rates?
ANSWER:
•
Based on Table 20-1 for a modem Tx bandwidth of 2.5 Mbps, the QoS output bandwidth is
set to 3 Mbps.
•
Since the modem Tx bandwidth and QoS output data rates are not the same, after Layer 2
QoS prioritization the modem will further limit the output data rate to the Tx bandwidth of
the mode. The individual port data rates will henceforth be trimmed (normalized) to the
data rate of the modem Tx bandwidth without considering the priorities.
R–4
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MN-CDM625A