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Why 11n wireless throughput is so slow?
I have Fortinet FAP220B access point supports 802.11n.
I have 3 laptops in testing.
pc1 is connected to FAP through wirless at 100Mbps.
pc2 and pc3 are connected to FAP wirlesslessly using 11n 5GHz. Channel bonding is enabled on both FAP and pc2 and pc3. The Windows show the wireless connection speed is 270Mbps on pc2 and pc3.
There is no radio interference in the test environment.
I use iperf to test the throughput.
Test1:
pc1: run iperf -s
pc2: iperf -c <pc1>
The throughput is only 20-30Mbps.
Q#1. Why throughput is 20Mbps not somewhere around 100Mbps?
Test2:
pc2: run iperf -s
pc3: iperf -c <pc2>
The throughput is usually around 15Mbps.
Q#2. Why the throughput is not around 150Mbps?
I researched the Internet and found out someone can get around 100Mbps wireless throughput using 11n.
Please comment on my test results and share your experience on 11n performance.
Thanks a lot.
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ASKER
Laptops are Windows 7 Pro, running on AC adapter. Wireless NIC settings are ok, e.g. Full transmit power.
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ASKER
The test machine is doing nothing but one thread of iperf.
I also tried different wireless NIC and never see throughput over 30Mbps.
I never get any results near 65Mbps. I'm also puzzled by the following result:
When only 1 pc connected wireless to AP, iperf shows about 25Mbps throughput; When 2 pc connected wireless to AP, running iperf at the same time on both pcs shows the aggragated throughput is around 25Mbps. Is it normal?
I also tried different wireless NIC and never see throughput over 30Mbps.
I never get any results near 65Mbps. I'm also puzzled by the following result:
When only 1 pc connected wireless to AP, iperf shows about 25Mbps throughput; When 2 pc connected wireless to AP, running iperf at the same time on both pcs shows the aggragated throughput is around 25Mbps. Is it normal?
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ASKER
The AP wired port is 100Mbps. But single wireless client gets only 25Mbps, far less than 100Mbps. Thus so far, the issue should NOT be related to the 100Mbps AP wired port yet.
ASKER
Thanks.
ASKER
I do use WPA2 AES enterprise as security.
All the numbers are in Mega bit per second (Mbps), not byte.
Do you mean 20Mbps is normal for 11n? The vendor claims up tp 300Mbps throughput. What's your experience on 11n? How to get the best throughput?
Thanks.