ATV2 and Time Capsule

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Ned Scott Offline
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Post: #11
bonic38 Wrote:Hello,

I've got a timecapsule (4th gen) and ran initially into problems (with AFP giving even worse results than SMB). Those seems to be solved by changing TCP ACK settings in sysctl.conf on the ATV2 :

/etc/sysctl.conf :
net.inet.tcp.delayed_ack=1

Note that the value "0" simply don't work.

Playing high bitrates 1280p mkv now works like a charm with AFP - occasional stuttering may appear with SMB, but it is ways better than before (systematic buffering). Using Wifi.

Worth a try i think.

Sounds like we're on to something here!
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Jester Offline
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Post: #12
bonic38 Wrote:Hello,

I've got a timecapsule (4th gen) and ran initially into problems (with AFP giving even worse results than SMB). Those seems to be solved by changing TCP ACK settings in sysctl.conf on the ATV2 :

/etc/sysctl.conf :
net.inet.tcp.delayed_ack=1

Note that the value "0" simply don't work.

Playing high bitrates 1280p mkv now works like a charm with AFP - occasional stuttering may appear with SMB, but it is ways better than before (systematic buffering). Using Wifi.

Worth a try i think.


Nice one !

you can use
Code:
sysctl -w net.inet.tcp.delayed_ack=1
to try it "live"
the setting will be lost on reboot, if it works fine, create a /etc/sysctl.conf and put the line in there as indicated by bonic38

Current XBMC Platform: ATV2
Extra XBMC Platform: Raspberry Pi
Read the iOS FAQ
(This post was last modified: 2011-12-13 13:59 by Jester.)
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Jester Offline
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Post: #13
P.S.

as i'm now playing around with this, I just noticed the default maximum Segment Size is only 512 (probably done for wifi ??) however if you run a wired setup this is a bit low, as with ethernet you can use frame sizes of 1500 (minus TCP overhead) so this can be increased to 1440

so

Code:
sysctl -w net.inet.tcp.mssdflt=1440

Might give some more wired network speed, again this is only doing the setting live, you will loose it on reboot, for permanent, put it in /etc/sysctl.conf

Current XBMC Platform: ATV2
Extra XBMC Platform: Raspberry Pi
Read the iOS FAQ
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MrTraverso Offline
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Post: #14
I've open the post but i have not solved the problem. I can't find a sysctl in AT2.
Help me please.
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GnarusLeo Offline
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Post: #15
Hi,

this did definately change something. The moment I used delayed_ACK=1, all my movies would buffer much more rapidly I'm affraid.

Nevertheless, this might be onto something. I have played with alot of these sysctl settings, but yet to find a good setup for my rig. (Which should be pretty standard: ATV2 -> CAT6 -> Time Caspule

As to the OP:

If the file isn't there, simply create it. I prefer installing nano first, and edit my files directly through SSH:

1. apt-get install nano
2. nano /etc/sysctl.conf
3. type whatever you want accoring to previous posts
4. Press ctrl-o, confirm by "y", and ctrl-x to quit again.
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bonic38 Offline
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Post: #16
In fact this gives for me good results on Wifi, but when wired I'm always buffering... Need to check why, I have no clue at this time.

Tried to play also with receive buffer size with no success...
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Benjopa Offline
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Post: #17
A few days ago i have also bought a Time capsule 2 Tb, but at the momente i am very disappointed. Befaore i stream all my movies, 720p and 1080p from my pc winth Windows 7 and i have had never buffer problem. With Time capsule is really a nightmare, because the movies continue to buffer repeatly, without difference between 720p and 1080p. With Samba is still worse. With AFP i have some random crash, and buffer is reduced but still there.
I have tried the tcp Ack, but buffer in wired connection is the same, while i have noticed an improvement in Wi-fi connection. In a topic that i have opened months ago, an user suggest infat to use wi-fi connection, but the problems remain and is very frustrating.
So i am really thinking to return back to the shop the Time capsule that is my really first disappointment since i use Apple products.
(This post was last modified: 2011-12-15 15:23 by Benjopa.)
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Jester Offline
XBMC for iOS* forums Moderator
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Post: #18
So, currently we can confirm that changing TCP ACK settings ONLY helps when using WiFi.

It's an important note so I'll add that to the wiki

Current XBMC Platform: ATV2
Extra XBMC Platform: Raspberry Pi
Read the iOS FAQ
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Jester Offline
XBMC for iOS* forums Moderator
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Post: #19
Can somebody on a wired Time Capsule test to see if the line below gives any improvement ?


Code:
sysctl -w net.inet.tcp.mssdflt=1440

Current XBMC Platform: ATV2
Extra XBMC Platform: Raspberry Pi
Read the iOS FAQ
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Benjopa Offline
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Post: #20
Sure, this evening i'll test this string and post the result.
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