Appendix F - Troubleshooting

F.3 Low Throughput Problems

Problem and Indication

 

Possible Cause

 

 

Corrective Action

 

 

 

 

 

 

 

 

 

 

 

 

Low throughput is suspected

 

Ethernet link problems

 

„ Verify proper settings of Ethernet

 

 

 

 

 

operation mode (actual Ethernet speed

(Check the dominant Modulation

 

 

 

 

of 100 Mbps).

Level in Per rate Counters and

 

 

 

 

„ Check Ethernet counters

see expected throughput in the

 

 

 

 

 

 

 

 

 

 

 

Wrong configuration of

 

Verify that Maximum Modulation level is not

“Expected Throughput” table

 

 

 

Maximum Modulation

 

set to a value that is not too low according to

below)

 

 

 

level

 

the “Recommended Maximum Modulation

 

 

 

 

 

 

 

 

Level” table below.

Low throughput of

 

Non-optimal configuration

 

A value that is too low (see the

multicast/broadcast traffic

 

of Multicast Modulation

 

“Recommended Maximum Modulation Level”

 

 

level

 

table below) may degrade throughput of

 

 

 

 

 

broadcast and multicast traffic.

High retransmissions rate

 

Interference problems

 

Check for interference using the Spectrum

 

 

(retransmissions rate in

 

Analysis Mode. If necessary, change the

 

 

excess of 15%)

 

operating frequency of the AU.

 

 

 

 

 

 

 

 

Expected Throughput in Mbps, TCP Traffic @ 20 MHz Bandwidth,

 

 

 

Burst Mode Enabled, Concatenation Enabled

 

 

 

Unit

TCP Traffic

 

 

 

Modulation Level

 

 

 

 

 

1

2

3

4

5

6

7

8

SU-3

Uplink

1.9

1.9

1.9

1.9

1.9

1.9

1.9

1.9

 

Downlink

2.9

2.9

2.9

2.9

2.9

2.9

2.9

2.9

 

Aggregate (Bi-directional)

3.3

3.3

3.3

3.3

3.3

3.3

3.3

3.3

SU-6

Uplink

3.8

3.8

3.8

3.8

3.8

3.8

3.8

3.8

 

Downlink

4.8

5.6

5.6

5.6

5.6

5.6

5.6

5.6

 

Aggregate (Bi-directional)

5

6.7

7

7.1

7.1

7.2

7.2

7.2

SU-54

Uplink

4.7

6.7

8.9

12.4

15.8

21

25.1

26.4

 

Downlink

4.8

7.1

9.4

13.7

17.7

24.7

28.9

30.1

 

Aggregate (Bi-directional)

4.8

7

9.3

13.1

16.9

22.8

29.4

32

* The throughput results are for net TCP traffic (excluding protocols overheads)

BreezeACCESS VL System Manual

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Image 272
Alvarion SW VERSION 5.1 system manual Low Throughput Problems, SU-6, SU-54