[Apple TV 2] - Buffering with Wireless-N
#1
Help me understand this.

I have wireless-N router set up as a wireless bridge which is fed by a 100Mb connection to the LAN. My ATV2 gets a perfect signal but when I stream large files like a 3d movie, it buffers badly. As a test, I connected it with ethernet cable to the same N router and it doesn't buffer at all. If wireless-N can handle 300Mbps then why would I be having issues when I am only trying to get 100Mbps?

Thanks,

David
#2
Update: I can connect to the same wireless-N network with my MAC and I get a 300Mbps connection to the router and have no trouble streaming the video to my MAC. It makes no sense that it works with 100Mb from a cat5 and not 300Mb wireless on the same wouter. I should get at the very lease 100Mbps on the wireless connection.

How can I test the connection speed on the ATV2 via command line?

David
#3
"It makes no sense that it works with 100Mb from a cat5 and not 300Mb wireless on the same wouter. I should get at the very lease 100Mbps on the wireless connection."

A wired connection is always better than any wireless connection. The problem with wireless is, that you don't have a constant transfer rate. The wired connection delivers only 100 Mbit/s per second but constant. That's a lot better.

I had buffering problems with my ATV2 streaming 720p content via Wlan-n, too. Than i connected it via Powerlan (only 80 Mbit/s)! to the Router and it works.

I think MKV 1080p content needs around 15 Mbit/s constant transfer rate (not shure about that)
#4
Streaming 1080p via wireless needs careful planning and an in-depth knowledge of wifi.

The fact that you think you should be getting 300Mbps actual throughput suggests you don't have the second. Please note no offence intended at all.

It would take too long for me to explain everything, you need to research it yourself. Make sure you learn about different frequency bands, bonded channels, the difference between a single-radio and dual-radio router. Research the fact that wifi is effectively half-duplex (router cannot send and receive simultaneously on same band) and what that does to throughput depending on how the server and client are connected and other traffic on the network.

Learn about how wifi routers need to switch back and forth between modes and bands depending on what devices are connected, and learn how legacy devices can bottleneck faster devices on the same network. Learn about how congested the 2.4GHz band is, and what effect all the interference (including your neighbours wifi) will do with regards to connection quality.

Learn about different streaming protocols and their associated overheads. Overhead is extra data that gets sent on top of the raw data you are trying to stream.

Etc.

After you learn all that, with careful planning you might be able to set up a wireless network that can stream 1080p rips. But you may find you need to upgrade your router or get rid of old legacy devices on your network (PS3 etc)

Full BD is pretty much out of the question.
#5
Thanks for the replies. I did some ping tests from the ATV2 to the router and the results were very inconsistant ranging from 4ms to 20ms. The MAC however had a more consistant 4 to 6 ms. It just seemed strange that my MAC gets a better throughput than the ATV2

Everything in my house is wired other than this ATV2, because of it's location. I have found that on the ATV2 over wireless I can watch just about everything but it's starts buffering every few minutes when I try to watch 3d stuff. With the wires its ok.

I guess I'm going to run a wire. I'll probably hardly ever watch 3D movies, but I guess if I want it done right I better run the wire.

Thanks,

David
#6
A nice alternative to running a wire is the Netgear AV+500 powerline networking kit. While I was not able to get the "near gigabit" speeds promised, the throuput was sufficient to stream 1080p MKV files to my Ubuntu laptop and my HTPC. I have had poor results playing 1080p MKV files on my ATV2 with both wired and wireless connections, but others have had success with HD playback.

Best of luck to you.
#7
voochi Wrote:Streaming 1080p via wireless needs careful planning and an in-depth knowledge of wifi.

The fact that you think you should be getting 300Mbps actual throughput suggests you don't have the second. Please note no offence intended at all.

No offense taken. I didn't think I would really be getting 300Mbps but I thought that I could get at lest 100Mbps or close, at a constant rate if the router could burst to 300Mbps. Also, the MAC did get a constant rate and worked fine. It was only the ATV2 that had issues, which leads me to believe that the ATV2 has an inferior network interface.

voochi Wrote:After you learn all that, with careful planning you might be able to set up a wireless network that can stream 1080p rips.

I am watching a 1080p version of Avatar right now over wireless and it is playing perfectly, it's the 3D movies it buffers on the most. So I guess I have a pretty good connection, just not quite good enough for 3D. I'm just going to run a wire, it will be complete in less than an hour and I can move on. :-)
#8
djonesax Wrote:No offense taken. I didn't think I would really be getting 300Mbps but I thought that I could get at lest 100Mbps or close, at a constant rate if the router could burst to 300Mbps. Also, the MAC did get a constant rate and worked fine. It was only the ATV2 that had issues, which leads me to believe that the ATV2 has an inferior network interface.



I am watching a 1080p version of Avatar right now over wireless and it is playing perfectly, it's the 3D movies it buffers on the most. So I guess I have a pretty good connection, just not quite good enough for 3D. I'm just going to run a wire, it will be complete in less than an hour and I can move on. :-)

Wire ran, runs perfect!
#9
The wifi chip inside the ATV2 gets like 60-70 Mbps.
#10
Ned Scott Wrote:The wifi chip inside the ATV2 gets like 60-70 Mbps.

^ This.

If its the same chip in the iphone4, (Broadcom 4329) http://www.datasheetdir.com/BCM4329+download

it has max of MCS index of 7 with 1 spatial stream.

http://en.wikipedia.org/wiki/IEEE_802.11...Data_rates

About 72 Mbps in a perfect world. 60-70 in the real world.
#11
imho mcs 7 with one antenna only gives us 65mbit/s brutto. ... just scratch wifi on idevices when trying to stream 1080p in a reliable way imho...
AppleTV4/iPhone/iPod/iPad: HowTo find debug logs and everything else which the devs like so much: click here
HowTo setup NFS for Kodi: NFS (wiki)
HowTo configure avahi (zeroconf): Avahi_Zeroconf (wiki)
READ THE IOS FAQ!: iOS FAQ (wiki)

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[Apple TV 2] - Buffering with Wireless-N0