Slow AC wireless link to one device only on network

[Rohan]

Hi
I hope I can get some help where to look next for possible solutions to my problem:

I have recently purchased a new Qnap 231 NAS with 2 3TB Western Digital Red drives in Raid 1
I have a Netgear D6300 wifi router that the QNAP is connected to by 1000 Mb/ethernet cable connection

When I connect my laptop ( Windows 8.1, i7) via the router using an ethernet cable or via N wifi to the Qnap I get the expected stable transfer speeds to and from the Qnap. i.e. via 1000 Mb/s cable around 90 - 110MB/s, via N 300 Mb/s wifi around 16 - 18 MB/s. However when I connect via AC 866 Mb/s wireless I only get around 2 MB/s and the transfer speed is very variable and often drops to zero for several seconds multiple times during the transfer.

If I use my AC wifi to transfer data to another laptop connected to the router by cable I also get the expected and stable transfer speeds of around 25 MB/s.

So why is it just with the QNAP on AC wireless that I get the problem? All the elements in the link when tested separately via other devices work OK but when put together as Laptop>AC wifi>router>ethernet cable>QNAP it slows to a crawl. Its got to be something in the QNAP setup and how it reacts uniquely to AC wifi to slow the data transfer

What have I tried so far:

• I have also tried a Netgear AC6200 USB wifi adapter and the speed loss when using AC to the QNAP is the same and running 2 MB/s and intermittent and the better performance on N is also the same at around 15MB/s
• The frequency bands I am using are clear and there are no other devices operating on the network during these tests.
• I have done the tests with a range of files size and types and this appears to make only the expected differences in all cases with many small files transferring slower than 1 large file.
• I have reset and rebooted everything multiple times, I am using the factory configuration for the QNAP
• All the software and firmware is the latest releases.
• The tests are all done in a single room with short Cat5 cables or wifi links over about 3 metres and strong wifi connection signal strengths

Any suggestions on where next to look would be greatly appreciated.
cheers
Rohan

 

[Rohan]

Next test just done:

I have tried a second laptop running windows 7 and it has exactly the same problems - slow on AC Wifi but OK on cable and N connection through the router to the Qnap. Definitely something about how the Qnap / router combination reacts to the use of the AC protocol as everything else is different. The AC wifi going to other devices through the router with the second laptop is similarly at expected speeds like the first laptop - it is just the Qnap that is a problem

cheers
Rohan

 

[Rohan]

Next test just done:

I tried the QNAP file manager application rather than windows copy for the file transfer from laptop to Qnap and back.

I now get the expected 25 MB/s transfer rate over the AC 866 Mb/s wifi !!!!!!

So it appears to be something to do with the windows copy process over the AC wireless that is upsetting the Qnap and slowing down the whole process - any one got any ideas

cheers
Rohan

 

[thiggins]

Windows file copy does a lot of stuff behind the scenes to optimize throughput, including adjustments for the network connection. This could be working against you.

Does the QNAP file manager use FTP? Have you tried using Windows robocopy?

Here are some other ideas
http://answers.microsoft.com/en-us/...machines/b8736b1b-0a91-4567-ba33-215084ffc906

 

[Rohan]

Hi Tim
Thanks for the feedback - I love the smallnetbuilder site and its my go to reference for networking now.

I have no idea what protocol the Qnap file manager uses but it is clearly different from Windows file copy protocol and appears to be avoiding the "windows file copy over AC to Qnap slowdown" problem I experience. I looked through the MS stuff you posted but most of it appears to be MS people guessing at answers and most of it applies to N wifi which is not a problem for me and most of the suggested solutions dont appear to have worked anyhow.

I spent a few happy hours today trying to see what else exists on the internet around this sort of problem and while a number of people report very similar issues with both Qnap and other linux based NAS no one has any specific ideas on what causes it from what I can see. Lots of guesses but I have tried them all pretty much and nothing appears to make much difference. I appear to have got further than most in narrowing it down to some interaction between windows file copy, AC wireless and a linux NAS (Qnap in my case) but that then takes it beyond my limited networking knowledge.

I will try the Qnap tech support next but I will not be holding my breath. i would really like to see if someone can duplicate the problem or not on a similar setup. In particular it would help to understand if the AC wifi section in the Netgear D6300 router is the problem or if other routers have the same problem. I cant really afford to buy another router to test it myself.

cheers
Rohan

 

[thiggins]

I'd at least try the netsh commands and see if that helps.

While the posts refer to N, AC and N share similar network throughput compression and optimization schemes.

 

[Rohan]

I'd at least try the netsh commands and see if that helps.

While the posts refer to N, AC and N share similar network throughput compression and optimization schemes.

Hi Tim
Yes I understand that, but it cant be related to those aspects that are common to N and AC as I do not have a problem with speed to the QNAP when using a N wifi connection. The problem only exists just when I use an AC connection. So it must be something different in AC versus N protocols ( or how it is implemented in the Netgear D6300 or the intel AC wifi adapter) that in combination with use of windows file copy to a Qnap NAS (or any Linux based NAS?) that causes the problem.

If someone has similar equipment it would be good if they can replicate the problem. If someone has different equipment it would be good to know if they don't have the problem when doing a similar file copy using window.

I will try the netsh commands like you suggest to see if it makes a difference

cheers
Rohan

 

[thiggins]

Sorry I missed the part about N being ok. Let us know if the netsh commands work.

 

[remixedcat]

If you wanna stay netgear get the 6210... much better than my old 6200.

 

[Rohan]

Hi Tim
I tried the various netsh autotuninglevel change steps in the link you posted and it made no difference still very slow (1 -3 MB/s) and variable speed file transfers and periods when they come to a dead stop for several seconds.

The problem does not appear to be with network speed itself as the AC (and N) works fine transferring files to another windows computer using windows file copy.

The problem relates specifically and only to using windows file copy over AC to or from the Qnap. The fact that Qnap include their file manager app as an alternative to windows file copy suggests they know this problem exists. Time for a chat with Qnap tech support I think

Hi remixedcat
The D6210 appears to be a european or chinese specific version of the D6200 from what I can see searching the internet. It is not sold here in Australia. The D6300 appears similar to it but just has an extra USB port. I dont really want to change my Netgear D6300 modem router as I can live with the problem of the slow windows file copy to the Qnap using the AC wireless by either using a N connection which is working OK or using the Qnap file manager which is working OK.

However I would like to fix the problem using the AC with windows file copy to my Qnap NAS more out of interest than anything else !

If i buy a new router it may still be the same problem as most of them use the same chips and the root cause may not be just in the router itself but in the combination of windows file copy protocol and AC protocol and / or in the AC adapter in my laptop or the router.

regards
Rohan

 

[remixedcat]

A6210 adapter I mean...

 

[Rohan]

A6210 adapter I mean...

Hi remixedcat

OK - looks like a usb 3 version of my a6200 usb adapter. Do you know if anything else is different such as the chip or firmware? The internal intel AC7620 mini PCI card adapter I have runs fine and a little faster than the external usb2 adapter. The problem I have with AC copies to the Qnap exists with both the adapters - maybe they run the same chip and firmware or maybe different but I cant afford random changes in hardware unless someone can demonstrate conclusively it solves the problem.

Have you a setup like mine and get OK fie copy speeds over AC to a Qnap NAS? Some hard data on a setup that gets around 30 MB/s file copy using windows to a Qnap NAS over AC is what I am looking for

cheers
Rohan

 

[thiggins]

Hi Tim
I tried the various netsh autotuninglevel change steps in the link you posted and it made no difference still very slow (1 -3 MB/s) and variable speed file transfers and periods when they come to a dead stop for several seconds.

The problem does not appear to be with network speed itself as the AC (and N) works fine transferring files to another windows computer using windows file copy.

The problem relates specifically and only to using windows file copy over AC to or from the Qnap. The fact that Qnap include their file manager app as an alternative to windows file copy suggests they know this problem exists. Time for a chat with Qnap tech support I think.

Thanks for trying the netsh commands and reporting back.

I think you have narrowed it down to something in the QNAP. Let us know if you find out what the problem is.

 

[remixedcat]

I know the a6210 uses an ralink chipset

 

[Rohan]

I know the a6210 uses an ralink chipset

If the Netgear chip sets on the A6200 and A6210 adapters are different to the intel chipsets on the Intel AC7260 mini PCI wifis adapter card then i can rule out the adapters as the source of the problem as I have the same problem with both types of adapter.


cheers
Rohan

 

[Rohan]

Thanks for trying the netsh commands and reporting back.i.i

I think you have narrowed it down to something in the QNAP. Let us know if you find out what the problem is.

Hi Tim

QNAP came back very promptly to my tech support question as follows.

"Hi Rohan,
As I understand in short, problem happens only with AC standards transfer to Qnap, N wifi is ok.
Also Win to Win via AC - ok; QFile app to Qnap via AC - ok.
Win to Qnap via AC - no good.

I assume you do transfer via SMB (shared folders from NAS connected to Windows).
Please test with different SMB version: NAS WebUI - Control Panel - Network Services - Win/Mac/NFS - Microsoft Net. - Advanced - SMB 3.0 (probably 2.0 by default)
Then re-enable SMB connection in Microsoft Networking.
Also, try to Enable Asynchronous I/O
Let me know the results of testing.

Another thing to test. (when connected via AC and SMB transfer speed is 2Mb/s) Try to download the file from Qnap using File Station.
What is download speed? Can check in browser download manager

Did you have this problem with previous router? Do you have any other router to test?

On the router side, (if available) check the packets statistics, if any packets dropped/re-sent in AC compare to N wi-fi, or Win-Win compare to Win-Qnap connection.
Maybe it will shed some light."

My response to Qnap have been as follows and I am awaiting ideas on what to try next

"I tried the SMB change and the asynchronous I/O change but it made no difference
I discovered that the while the upload using the Qnap file station runs at 30 MB/s over AC which is what I would expect, the download only runs at 2MB/s just the same as when using windows file copy to or from the Qnap. It looks like the file station download protocol is the same as windows file copy while the upload uses something different ?

I unfortunately dont have another AC router to test it with and my previous router was N only which i dont have a problem with.

The Netgear genie application for my router does not give any packets drop information is there another easy way to monitor this?"

cheers
Rohan

 

[remixedcat]

uninstall the netgear genie and instead find the "driver only" and see if that helps. Genie uses a lot of CPU on some systems and using the standalone driver might help.

 

[Rohan]

uninstall the netgear genie and instead find the "driver only" and see if that helps. Genie uses a lot of CPU on some systems and using the standalone driver might help.

I will give it a try. But my laptop CPU, quad core I7- 4710MQ, 8gig Ram and SSD is only idling when I do all these tests. I have looked at cpu loads during the tests and the Genie app is not consuming a lot of cpu cycles if I have it running. During the slow transfers it appears that both the laptop cpu / disk and the Qnap cpu/disks are spending lots of time waiting to send or to receive data. So its something happening in between the two

Has anyone connected to a Qnap NAS using a windows computer and AC wireless out there that can tell me their results in a similar test???

cheers
Rohan

 

[Rohan]

I have been doing some packet capture with wireshark to try to understand more about what is going on that is slowing the AC file copy transfer to the Qnap versus the other options such as using the N wireless.

I have discovered that with the 16 MB/s N wifi copy, the transfer runs a NBSS session which is apparently a protocol used between two computers for efficient transfer of large files. The 2 MB/s or less AC copy never initiates this protocol between the Laptop and the Qnap and there are just a few SMB protocol packets scattered among many other data packages that appear to be doing nothing -- thus the slow data transfer

The next question is how do I get the NBSS protocol to initiate for an AC session when communicating with the Qnap

cheers
Rohan