Comtech EF Data CDM-425 Installation And Operation Manual page 718

QoS Example 4
SETUP:
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QUESTION:
What is the total output data rate and what are the individual port output data rates?
ANSWER:
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VLAN
Priority
7
5
3
1
Total ►
Appendix M
VLAN-based Layer 2 QoS mode is selected.
The modem data rate is set to 1 Mbps.
Four streams of VLAN ingress traffic is sent to the modem with VLAN Priorities
set to 7, 5, 3, and 1, respectively.
The data rate for each stream is set to 500 Kbps.
Based on Table M-1 for a modem Tx bandwidth of 1 Mbps, the QoS output
bandwidth is set to 1 Mbps.
Total Input data rate is 4X 500 Kbps = 2 Mbps
Based on Table M-2, the VLAN Priorities 7, 5, 3, and 1 are mapped, respectively,
to L2 QoS Priorities 4, 3, 2, and 1.
Since the modem Tx bandwidth and QoS output data rates are the same, there is
no need for normalization.
The data rate for each port is as follows:
L2 QoS Input Data
Priority Rate
4 500 Kbps
3 500 Kbps
2 500 Kbps
1 500 Kbps
2 Mbps
CDM-425 Advanced Satellite Modem
Remaining Data Rate
QoS Output
(After Serving the Priority
Data Rate
500 Kbps
500 Kbps
0 Kbps
0 Kbps
1 Mbps
M–6
Revision 0
Output Data
Rate
Queue)
500 Kbps 500 Kbps
0 Kbps 500 Kbps
0 Kbps 0 Kbps
0 Kbps 0 Kbps
0 Kbps 1 Mbps
MN-CDM-425