Comtech EF Data CDM-570A User Manual
Page 570
CDM-570A/570AL Satellite Modem with Optional Packet Processor
MN-CDM570A
Appendix L
Revision 2
L–10
QUESTION
: What is the total output data rate and what are the individual port output data
rates?
ANSWER:
•
The QoS system first drains Priority 1 traffic. Since the management data stream is only 200
Kbps, after serving Priority 1 traffic, QoS still has 9.8 Mbps (10.0-0.2=9.8).
•
QoS next drains Priority 2’s 800 Kbps traffic. After the end of the Priority 2 traffic, QoS still
has 9 Mbps traffic available (9.8-0.8=9).
•
Similarly, QoS walks through all priorities until it hits the ASFD classes:
o
The beginning of ASFD Classes QoS leftover bandwidth is 2 Mbps.
o
All ASFD classes have the same Priority of 7, with different service rates.
o
ASFD service rate is a Committed Information Rate (CIR), except serviced if bandwidth
available after serving all high priority queues. In this case, 2 Mbps bandwidth is
available, serving all service rates first. The total of all ASFD service rates are 1.6 Mbps,
which is less than the 2 Mbps leftover bandwidth.
o
After serving the service rates, the leftover bandwidth is 400 Kbps. This 400 Kbps will be
distributed to all ASFD classes equally in round robin fashion until either there is no
more bandwidth, or the input streams have no data.
• The resulting individual data rates are as follows:
Stream
Priority
PHB / DSCP Code
Service Rate
Drop Precedence
Data Rate
Management
1
CS7 / b111000
200 Kbps
9.8 Mbps
200 Kbps
Networking Control
2
CS6 / b110000
800 Kbps
9.0 Mbps
800 Kbps
Voice
3
EXFD / b101110
1 Mbps
8.0 Mbps
1Mbps
Video
3
CS5 / b101000
4 Mbps
4.0 Mbps
4 Mbps
Data-1
4
CS4 / b100000
550 Kbps
3450 Kbps
550 Kbps
Data-2
5
CS3 / b011000
1450
2000 Kbps
1450 Kbps
Data-3
7
ASFD4 / b100010
1 Mbps
NA
100 + 100 Kbps
Data-4
7
ASFD3 / b011010
1 Mbps
NA
400 + 100 Kbps
Data-5
7
ASFD2 / b010010
1 Mbps
NA
500 + 100 Kbps
Data-6
7
ASFD1 / b001010
1 Mbps
NA
800 + 100 Kbps
Data-7
8
BE / bXXXXXX
2 Mbps
NA
0 Kbps
Total
N/A
N/A
14 Mbps
0 Kbps
10 Mbps