On 09/10/14 03:26, Sourav wrote:
Hi All, We are using Ralink chip Rt3072L (using rt2800usb drivers rt2800usb.c), mac80211, and hostapd in our routers. root:~# lsmod Module Size Used by Tainted: P rt2800usb 15371 0 rt2800lib 74214 1 rt2800usb rt2x00usb 9718 1 rt2800usb rt2x00lib 39328 3 rt2800usb,rt2800lib,rt2x00usb mac80211 266596 3 rt2800lib,rt2x00usb,rt2x00lib cfg80211 214073 2 rt2x00lib,mac80211 compat 17406 4 rt2800usb,rt2x00lib,mac80211,cfg80211 When we are measuring performance using iperf, we see ~20Mbps, using Channel 11 of 2.4GHZ, using 802.11n. The following is the iperf stats with iperf client running on the router and iperf server running on a laptop with IEEE802.11n adapter. root:~# iperf -c 192.168.1.194 -p 5001 -i1 -fk -w146k -t100 ------------------------------------------------------------ Client connecting to 192.168.1.194, TCP port 5001 TCP window size: 292 KByte (WARNING: requested 146 KByte) ------------------------------------------------------------ [ 3] local 192.168.1.1 port 42520 connected with 192.168.1.194 port 5001 [ ID] Interval Transfer Bandwidth [ 3] 0.0- 1.0 sec 1560 KBytes 12780 Kbits/sec [ ID] Interval Transfer Bandwidth [ 3] 1.0- 2.0 sec 2672 KBytes 21889 Kbits/sec [ ID] Interval Transfer Bandwidth [ 3] 2.0- 3.0 sec 2800 KBytes 22938 Kbits/sec [ ID] Interval Transfer Bandwidth [ 3] 3.0- 4.0 sec 2624 KBytes 21496 Kbits/sec [ ID] Interval Transfer Bandwidth [ 3] 4.0- 5.0 sec 2712 KBytes 22217 Kbits/sec [ ID] Interval Transfer Bandwidth [ 3] 5.0- 6.0 sec 2664 KBytes 21823 Kbits/sec [ ID] Interval Transfer Bandwidth [ 3] 6.0- 7.0 sec 2424 KBytes 19857 Kbits/sec [ ID] Interval Transfer Bandwidth [ 3] 7.0- 8.0 sec 2424 KBytes 19857 Kbits/sec [ ID] Interval Transfer Bandwidth [ 3] 8.0- 9.0 sec 2592 KBytes 21234 Kbits/sec [ ID] Interval Transfer Bandwidth [ 3] 9.0-10.0 sec 2752 KBytes 22544 Kbits/sec [ ID] Interval Transfer Bandwidth [ 3] 10.0-11.0 sec 3024 KBytes 24773 Kbits/sec [ ID] Interval Transfer Bandwidth [ 3] 11.0-12.0 sec 2568 KBytes 21037 Kbits/sec [ ID] Interval Transfer Bandwidth [ 3] 12.0-13.0 sec 2832 KBytes 23200 Kbits/sec [ ID] Interval Transfer Bandwidth [ 3] 13.0-14.0 sec 2624 KBytes 21496 Kbits/sec We are expecting speeds of upto 300Mbps(as per 802.11n specs), though those speeds are achievable using channel bonding over 5GHZ?
First of all, the speeds in the 802.11n specs are phy rates. This rate is what is used for individual frames. So you are comparing apples and beans (not in the fruit department) by looking at TCP throughput. You will need to determine the actual phy rate during the test using iw. This depends on condition in the environment. 300Mbps requires two streams (2x2) and 40MHz bandwidth.
Regards, Arend
However at 2.4GHZ also we believe the speeds we are seeing are far too low....what are the maximum achievable speeds that we can expect in our setup and how to achieve them.....are there any performance tuning techniques that we can use....please reply asap as this is very urgent.
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