Comtech EF Data CDM-570A - 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