User's Manual

Appendix H - Troubleshooting
BreezeACCESS 4900 System Manual
236
H.3 Low Throughput Problems
Problem and Indication Possible Cause Corrective Action
Ethernet link
problems
 Verify proper settings of Ethernet
operation mode (actual Ethernet
speed of 100 Mbps).
 Check Ethernet counters
Low throughput is suspected
(Check the dominant
Modulation Level in Per rate
Counters and see expected
throughput in the “Expected
Throughput” table below)
Wrong configuration
of Maximum
Modulation level
Verify that Maximum Modulation level is
not set to a value that is not too low
according to the “Recommended
Maximum Modulation Level” table below.
Low throughput of
multicast/broadcast traffic
Non-optimal
configuration of
Multicast Modulation
level
A value that is too low (see the
“Recommended Maximum Modulation
Level” table below) may degrade
throughput of broadcast and multicast
traffic.
High retransmissions rate Interference
problems
(retransmissions rate
in excess of 15%)
Check for interference using the
Spectrum Analysis Mode. If necessary,
change the operating frequency of the
AU.
Expected Throughput in Mbps, TCP session,
Burst Mode Disabled
Modulation Level Expected Throughput (Mbps) @ 10 MHz Bandwidth
1 2.40
2 3.57
3 4.69
4 6.76
5 8.76
6 12.02
7 14.13
8 14.25