I am in desperate need of help to improve the abysmal performance of my 802.11n wireless network. At best I get 30Mbs (this is an internet download) from a technology that boasts 300Mbs, even worse is the LAN where to date the best I have ever gotten is 1Mbs. It is literally quicker to copy the file to a USB drive and walk it to the other computer.
Infrastructure is this
- AP 802.11n only broadcasting at both 2.4GHz and 5GHz
- Mac with 802.11a/b/g/n card is connected to the AP via 5GHz
- Linux with 802.11a/b/g/n card is connected to AP via 2.4GHz
I have conducted the following tests (results at end of post)
- Internet based speed test wired and wireless
- LAN file copy wired and wireless
I have read:
- Wireless Diagnostics & Troubleshooting:
Handheld And PC-Based Tools For RF And Wi-Fi Diagnostics - 5 Ways To Fix Slow 802.11n Speed
- 7 Tips to Increase Wi-Fi Performance
- Slow file transfer on network between two 802.11n laptops (connected directly together via access point)
- Wireless Network Performance Issues
- Slower than expected 802.11n wireless network speeds
I have made the following optimizations
- AP broadcasts only 802.11n on both 2.4GHz and 5GHz frequencies
- 2.4GHz is on a channel with least interference (live in an apartment with lots of APs), this did make a 10Mb/sec improvement
- Our AP is the only one transmitting on the 5GHz freq.
- Security: WPA Personal WPA2 AES encryption
- Bandwidth: 20MHz / 40MHz (I assume this to be channel bonding)
I have tried the following with 0 improvement
- Dropped the Fragment Threshold to 512
- Dropped the Request To Send (RTS) Threshold to 512 and 1
- Even thought of buying a frequency spectrum analyzer, until I saw the cost of them!!!
Speed test results
Linux Wired:
- DOWNLOAD 128.40Mb/s
- UPLOAD 10.62Mb/s
- http://www.speedtest.net/my-result/2948381853
Mac Wired:
- DOWNLOAD 118.02Mb/s
- UPLOAD 10.56Mb/s
- http://www.speedtest.net/my-result/2948384406
Linux Wireless:
- DOWNLOAD 23.99Mb/s
- UPLOAD 10.31Mb/s
- http://www.speedtest.net/my-result/2948394990
Mac Wireless:
- DOWNLOAD 22.55Mb/s
- UPLOAD 10.36Mb/s
- http://www.speedtest.net/my-result/2948396489
LAN NFS 53,345,087 bytes (51MB) file
- Linux Mac NFS Wired: 65.6959 Mb/sec
- Linux Mac NFS Wireless: .9443 Mb/sec
All help is appreciated, even testing methods will be accepted.
Best Answer
Sometimes you may have other devices using 2.4Ghz causing interference. Not sure if you have tried using a scanner to see if some other device is interfering. I've found this to be the case at my job where I had a similar situation and there was a telephone using 2.4Ghz that caused slowdowns.