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D-Link wireless N stuck at 39 Mbps

Fullmetal Chocobo

Fullmetal Chocobo

Moderator<br>Distributed Computing
Moderator
I have a D-Link DIR-825 connected to a D-Link DAP-1522 via a 5GHz wireless N connection operating on channel 40.

I'm finally getting the two to talk, but I'm transferring around 5 MB/s. Right now, both devices are in the same room, at the signal strength is 100%. At this opint I'm too tired to keep messing with it, but anyone have ideas as to where I should start looking?

For some reason, it is reporting the bridge's IP as 0.0.0.0 while I have it statically set to something else.

Yeehah.
 
Given Wireless overhead a transfer of 5 MB/sec. (B=Byte) is a result of about 50Mb/sec.

Signal strength in End-user Wireless means the total of the Signal and the Noise.

In sum what you get is probably what Functionally goes in the real world.
 
Originally posted by: spidey07
Sounds normal. How are you measuring thruput?
Click to expand...

Detailed information during file copy of Vista. The connection is listed at 39 Mbps. It should at least be connecting at 54, correct?
 
5MB/s transfer is 50Mbps or roughly 100Mbps half duplex. About what you should be getting.

Additionally, don't trust the "connection rating" Microsoft gives you. It's not accurate. If you really want to know how well you're doing, load up Netstumbler.
 
Originally posted by: Fullmetal Chocobo
Detailed information during file copy of Vista. The connection is listed at 39 Mbps. It should at least be connecting at 54, correct?
Click to expand...

No, the two are different measures, and the "54 Mb/s" marketing of standard-g only gives around 23 Mb/s actual throughput under ideal conditions, which are rarely reached. So by getting "39 Mb/s" actual throughput, you have already exceeded the "54 Mb/s" standard-g data rate.

BTW, Vista's dialog shows MiB/s, so you can add around another 5% to that for the equivalent actual MB/s. (Woo hoo!)

Suggestions for improvement:

1. WPA2
2. Experiment with location and orientation, esp. of the DAP-1522
3. Update firmware on both ends.
4. Try different channels.
5. Toggle 20 MHz vs 40 MHz
6. Dunno, reduce humidity?

iperf might be able to give some more testing capability, or at least an easily reproducible stream of measurements while you make adjustments.

E.g., WRT610N to DAP-1522, 5 GHz:

(Not the best I've reached, but also not the worst. I changed the orientation at around 60s)

F:\tools\bench\iperf>iperf -c barton-vista -l 64k -t 1500 -i 10
------------------------------------------------------------
Client connecting to barton-vista, TCP port 5001
TCP window size: 8.00 KByte (default)
------------------------------------------------------------
[652] local 192.168.0.189 port 28600 connected with 192.168.0.148 port 5001
[ ID] Interval Transfer Bandwidth
[652] 0.0-10.0 sec 104 MBytes 87.2 Mbits/sec
[652] 10.0-20.0 sec 104 MBytes 87.5 Mbits/sec
[652] 20.0-30.0 sec 105 MBytes 87.7 Mbits/sec
[652] 30.0-40.0 sec 104 MBytes 87.6 Mbits/sec
[652] 40.0-50.0 sec 104 MBytes 87.5 Mbits/sec
[652] 50.0-60.0 sec 96.9 MBytes 81.3 Mbits/sec
[652] 60.0-70.0 sec 95.3 MBytes 79.9 Mbits/sec
[652] 70.0-80.0 sec 105 MBytes 87.7 Mbits/sec
[652] 80.0-90.0 sec 106 MBytes 88.9 Mbits/sec
[652] 90.0-100.0 sec 107 MBytes 89.4 Mbits/sec
[652] 100.0-110.0 sec 106 MBytes 89.1 Mbits/sec
[652] 110.0-120.0 sec 107 MBytes 89.4 Mbits/sec
[652] 120.0-130.0 sec 107 MBytes 89.7 Mbits/sec
[652] 130.0-140.0 sec 106 MBytes 88.9 Mbits/sec
[652] 140.0-150.0 sec 106 MBytes 89.3 Mbits/sec
[652] 150.0-160.0 sec 106 MBytes 89.2 Mbits/sec
[652] 160.0-170.0 sec 107 MBytes 89.4 Mbits/sec
Click to expand...
 
Originally posted by: Madwand1
Originally posted by: Fullmetal Chocobo
Detailed information during file copy of Vista. The connection is listed at 39 Mbps. It should at least be connecting at 54, correct?
Click to expand...

No, the two are different measures, and the "54 Mb/s" marketing of standard-g only gives around 23 Mb/s actual throughput under ideal conditions, which are rarely reached. So by getting "39 Mb/s" actual throughput, you have already exceeded the "54 Mb/s" standard-g data rate.

BTW, Vista's dialog shows MiB/s, so you can add around another 5% to that for the equivalent actual MB/s. (Woo hoo!)

Suggestions for improvement:

1. WPA2
2. Experiment with location and orientation, esp. of the DAP-1522
3. Update firmware on both ends.
4. Try different channels.
5. Toggle 20 MHz vs 40 MHz
6. Dunno, reduce humidity?

iperf might be able to give some more testing capability, or at least an easily reproducible stream of measurements while you make adjustments.

E.g., WRT610N to DAP-1522, 5 GHz:

(Not the best I've reached, but also not the worst. I changed the orientation at around 60s)

F:\tools\bench\iperf>iperf -c barton-vista -l 64k -t 1500 -i 10
------------------------------------------------------------
Client connecting to barton-vista, TCP port 5001
TCP window size: 8.00 KByte (default)
------------------------------------------------------------
[652] local 192.168.0.189 port 28600 connected with 192.168.0.148 port 5001
[ ID] Interval Transfer Bandwidth
[652] 0.0-10.0 sec 104 MBytes 87.2 Mbits/sec
[652] 10.0-20.0 sec 104 MBytes 87.5 Mbits/sec
[652] 20.0-30.0 sec 105 MBytes 87.7 Mbits/sec
[652] 30.0-40.0 sec 104 MBytes 87.6 Mbits/sec
[652] 40.0-50.0 sec 104 MBytes 87.5 Mbits/sec
[652] 50.0-60.0 sec 96.9 MBytes 81.3 Mbits/sec
[652] 60.0-70.0 sec 95.3 MBytes 79.9 Mbits/sec
[652] 70.0-80.0 sec 105 MBytes 87.7 Mbits/sec
[652] 80.0-90.0 sec 106 MBytes 88.9 Mbits/sec
[652] 90.0-100.0 sec 107 MBytes 89.4 Mbits/sec
[652] 100.0-110.0 sec 106 MBytes 89.1 Mbits/sec
[652] 110.0-120.0 sec 107 MBytes 89.4 Mbits/sec
[652] 120.0-130.0 sec 107 MBytes 89.7 Mbits/sec
[652] 130.0-140.0 sec 106 MBytes 88.9 Mbits/sec
[652] 140.0-150.0 sec 106 MBytes 89.3 Mbits/sec
[652] 150.0-160.0 sec 106 MBytes 89.2 Mbits/sec
[652] 160.0-170.0 sec 107 MBytes 89.4 Mbits/sec
Click to expand...
Click to expand...

I'm getting 5 MB/s throughput, not 39 MB/s throughput. I'm getting a maximum connection of 39 Mbps as reported from the firmware of the router.

The devices are currently about 3 feet away from each other (for testing purposes). Updated firmware on both ends. On the bridge, I'm not able to change channel, 20/40MHz, etc, so I guess it is merely dependent on the router signal it is being bridged to. The router is currently operating at 5GHz on channel 40. Had a machine go down last night, so I haven't had much time to mess with this though.
 
Originally posted by: Fullmetal Chocobo
Originally posted by: Madwand1
Originally posted by: Fullmetal Chocobo
Detailed information during file copy of Vista. The connection is listed at 39 Mbps. It should at least be connecting at 54, correct?
Click to expand...

No, the two are different measures, and the "54 Mb/s" marketing of standard-g only gives around 23 Mb/s actual throughput under ideal conditions, which are rarely reached. So by getting "39 Mb/s" actual throughput, you have already exceeded the "54 Mb/s" standard-g data rate.

BTW, Vista's dialog shows MiB/s, so you can add around another 5% to that for the equivalent actual MB/s. (Woo hoo!)

Suggestions for improvement:

1. WPA2
2. Experiment with location and orientation, esp. of the DAP-1522
3. Update firmware on both ends.
4. Try different channels.
5. Toggle 20 MHz vs 40 MHz
6. Dunno, reduce humidity?

iperf might be able to give some more testing capability, or at least an easily reproducible stream of measurements while you make adjustments.

E.g., WRT610N to DAP-1522, 5 GHz:

(Not the best I've reached, but also not the worst. I changed the orientation at around 60s)

F:\tools\bench\iperf>iperf -c barton-vista -l 64k -t 1500 -i 10
------------------------------------------------------------
Client connecting to barton-vista, TCP port 5001
TCP window size: 8.00 KByte (default)
------------------------------------------------------------
[652] local 192.168.0.189 port 28600 connected with 192.168.0.148 port 5001
[ ID] Interval Transfer Bandwidth
[652] 0.0-10.0 sec 104 MBytes 87.2 Mbits/sec
[652] 10.0-20.0 sec 104 MBytes 87.5 Mbits/sec
[652] 20.0-30.0 sec 105 MBytes 87.7 Mbits/sec
[652] 30.0-40.0 sec 104 MBytes 87.6 Mbits/sec
[652] 40.0-50.0 sec 104 MBytes 87.5 Mbits/sec
[652] 50.0-60.0 sec 96.9 MBytes 81.3 Mbits/sec
[652] 60.0-70.0 sec 95.3 MBytes 79.9 Mbits/sec
[652] 70.0-80.0 sec 105 MBytes 87.7 Mbits/sec
[652] 80.0-90.0 sec 106 MBytes 88.9 Mbits/sec
[652] 90.0-100.0 sec 107 MBytes 89.4 Mbits/sec
[652] 100.0-110.0 sec 106 MBytes 89.1 Mbits/sec
[652] 110.0-120.0 sec 107 MBytes 89.4 Mbits/sec
[652] 120.0-130.0 sec 107 MBytes 89.7 Mbits/sec
[652] 130.0-140.0 sec 106 MBytes 88.9 Mbits/sec
[652] 140.0-150.0 sec 106 MBytes 89.3 Mbits/sec
[652] 150.0-160.0 sec 106 MBytes 89.2 Mbits/sec
[652] 160.0-170.0 sec 107 MBytes 89.4 Mbits/sec
Click to expand...
Click to expand...

I'm getting 5 MB/s throughput, not 39 MB/s throughput. I'm getting a maximum connection of 39 Mbps as reported from the firmware of the router.

The devices are currently about 3 feet away from each other (for testing purposes). Updated firmware on both ends. On the bridge, I'm not able to change channel, 20/40MHz, etc, so I guess it is merely dependent on the router signal it is being bridged to. The router is currently operating at 5GHz on channel 40. Had a machine go down last night, so I haven't had much time to mess with this though.
Click to expand...

If you are getting 5 MBytes throughput on wireless, that is perfectly normal, as others on here have said. I'm not sure if you just didn't read the other comments or what but others have said the same thing. 5mByte/sec on wireless is about what you'd see in the real world on N

-Also, if your connection is at 39mbits, bits and bytes are NOT the same. 39mbit connection with 5mbyte/sec throughput is pretty much normal.
 
Originally posted by: Fullmetal Chocobo
I'm getting 5 MB/s throughput, not 39 MB/s throughput. I'm getting a maximum connection of 39 Mbps as reported from the firmware of the router.
Click to expand...

Of course you're not getting 39 MB/s, that would be gigabit-level speed.

1 B = 1 Byte = 8 bits = 8 b.

5 MB/s = 5 * 8 Mb/s = 40 Mb/s =~ 39 Mb/s.

These figures are consistent, but also probably misleading. There's no way that you would get 40 or even 39 Mb/s actual file transfer throughput if your data rate was only 39 Mb/s -- there's lots of additional overhead that has to fit into that data rate. What's probably going on is that the router is reporting single-stream data rate, and actually running parallel streams, so that the aggregate data rate and throughput potential is higher. My router avoids this confusion by not reporting the data rate.
 
Originally posted by: spidey07
3 feet is too close.
Click to expand...

Excellent. Move the bridge downstairs, and bridge is now connecting at 52Mbps and netbook is connecting at 62. Thank you very much. That seems much more reasonable than a maximum of 39.
 
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