Strange throughput between wired and wireless

I set up my asus rt-ac66u following the best practices found in the FAQ section of ASUS site.
I'm using it with 3 different devices: 2 windows 7 pro 64 bit both with a linksys wmp600n (dual band 300n pci card) and one qnap nas connect directly to the router with rj45 cable.
I did some testing (both via CIFS and FTP protocol) and I got some strange results...

FTP transfers via wireless between the 2 PC goes at a 7-8 MB/s (I have no idea if this speed should be considered a good throughput for 5ghz 300mb/s wireless network)

FTP upload from a pc to the wired QNAP NAS has a throughput of 25 MB/s

FTP download from QNAP NAS to wireless PC only goes at 1,2 MB/s!!!!!!!!!!

I really don't understand this enormous (and inaccettable) trhoughput between download and upload from the wired NAS!!!!

What I'm doing wrong???
upload.jpg
Download.jpg
Markisha1979Asked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

SteveCommented:
this is usually due to interference.
The WIFI traffic can be affected differently for uploads & downloads for various reasons that it may not be worth going into detail for.

try moving the PCs/wifi hardware and turning off ANYTHING that could interfere (including other wifi devices) to see if this balances your results out a bit.

with regard to the throughput:
(I have no idea if this speed should be considered a good throughput for 5ghz 300mb/s wireless network)

bandwidth is measured in BITS not BYTES so you always need to start with a conversion between the two.

IE 300Mbits/s = 37.5MBYTES/s (just divide by 8)

This means a 300Mb/s connection could THEORITICALLY handle a max of 37.5 MB/s (note the lowercase b in 300Mb/s to denote bits instead of bytes)

theoretical max is very hard to reach though, so most tend to work on about 75% of the max as a realistic target. This is due to other traffic, distance between wifi hardware, interference, signal reflection & many other technical things.
0
Markisha1979Author Commented:
Thank you for your reply.

I know that I cannot pretend to reach the theorical speed but, comparing the theorical 37,5 MB/s with my results I have the following consideration:

the throughput of 25 MB/s obtained in ftp upload from client to the wired NAS is ok
The throughput of 7-8 MB/s obtained between the 2 wireless client is not so good (2 channel at 8 MB/s = 16 MB/s.... lower than the half of theorical speed)
the throughput of 1,2  MB/s obtainedin ftp download from client to the wired NAS is ridicolous....

I'm aware of wifi interference problem but, as I said before, I paid attention to use a free transmission channell and, in addition, if this is a interference problem why I have slow transmission in download and not in upload?

sorry for my english, I hope you can understand.
0
SteveCommented:
The throughput of 7-8 MB/s obtained between the 2 wireless client is not so good
Traffic between 2 wifi clients will always be slower because only one of the clients can send/receive packets via wifi at a time as they are sharing the same WIFI system and channels. Unfortunately, there is also a lot of overhead and administrative traffic on WIFI  (and a lot of collisions/retransmits) involved so your results are not far off I'm afraid.

The 1.2MB/s download speed is definitely a little poor though. I think that's the only one you really need to investigate as that definitely is a bit low.

try connecting that client by cable and rerunning the test t make sure the WIFI is the reason it's so slow.
0
Determine the Perfect Price for Your IT Services

Do you wonder if your IT business is truly profitable or if you should raise your prices? Learn how to calculate your overhead burden with our free interactive tool and use it to determine the right price for your IT services. Download your free eBook now!

Markisha1979Author Commented:
Hello there,
thank you for you suggestion. I tryied with a patch cord attacched to the router and the results are fine (90MBs, with a 1 Gbs network speed).
I find a new firmware from the asus web site and it did the tricks: upload and download speed are now the same (25MB/s)...

Just another think, for curiosity.

You said that 7/8 MBs has to be considered a pretty good results because of a sort of "half duplex" management of the available wifi throughput. But with the new beamforming tecnology cooperating with MIMO antennas (My client PCI network card has 2 antennas and the router 3) transferring at 5 Ghz should not make obsolete this kind of problems?
0
SteveCommented:
You said that 7/8 MBs has to be considered a pretty good results because of a sort of "half duplex" management of the available wifi throughput. But with the new beamforming tecnology cooperating with MIMO antennas (My client PCI network card has 2 antennas and the router 3) transferring at 5 Ghz should not make obsolete this kind of problems?

No, in practice many of these new technologies are just gimmiks and don't make a difference in a small network environment.
MIMO, for example, was originally designed for specialised point to point data transmission, not home wifi networks. it does have some advantages, but its not designed to allow two clients to communicate on the same frequency at the same time within a small network environment.

Without getting into the technical details, WIFI is a very messy area. it's a mix-match of various standards and protocols, implemented in a variety of different ways by different vendors. It also relies on the already overwhelmed airwaves and the various bits of interference, obstacles, reflections etc.

WIFI is all about theoreticals and real-life usage very rarely gets close.
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Markisha1979Author Commented:
The solution was provided by a firmware upgrade, but the experts' comments was clever and useful
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Wireless Networking

From novice to tech pro — start learning today.