Time Capsule slow file transfer

I have been testing Time Capsule very thoroughly. I've found out that wireless interference has a strong effect on network through-output. Best results were accomplished using N only wireless on the 2.4 ghz range. This could be just a local result from the location where I did the testing.

Look at the link jefos posted above. It details an insidious TCP/IP race condition the wireless link can fall into and a work-around for that problem.

I had problems too with my transfer speed. It was very slow. I throughly checked my network preferences for my ethernet connect and looked under the "advanced" tab. When I selected "Ethernet" tab within the "Advanced" tab I saw that my ethernet was manually set for only at 10 baseT/UTP. I have no idea why. I think it could have been switched when I upgraded Airport Utility to install my Time Capsule. I don't remember having that issue before I did the install. However, I wasn't running on a true gigabit network until I got the Time Capsule. You might want to check that just in case.

I am not sure if any of the "solutions" posted here actually fix the fundamental problem.

I just took a USB2.0 external drive (Seagate FreeAgent) and plugged it into the USB port of the TC. I then tried to transfer 30GB of data from the Seagate to the TC - told me it was going to take 3 hours!! There is no ethernet involved in this scenario - just a direct USB connection. This is ridiculous.

Does anyone know if there is a solution to this?

Message was edited by: doostang

doostang-

You have just piled onto an old thread with multiple posters and multiple unrelated problems in a part of the forums intended for Older \[pre 1997] Hardware Products. While your post is interesting, if you really want some assistance with your query, you should re-post in the Time Capsule forum, here:

Forum: Airport > Time Capsule

A quick tcpdump says that it's using ipv6 to communicate to tc by default.

If you go into your network settings and turn ipv6 off it goes a lot faster, but it's still not nearly as quick as it should.

You can also:
sudo sysctl -w net.inet.tcp.delayed_ack=0
sudo sysctl -w net.inet.tcp.rfc1323=0
sudo sysctl -w net.inet.tcp.recvspace=40960

To make it permanent, stick this in /etc/sysctl.conf:
net.inet.tcp.rfc1323=0
net.inet.tcp.delayed_ack=0
net.inet.tcp.recvspace=40960


For the curious:
http://www.stuartcheshire.org/papers/NagleDelayedAck/


-s

I can't tell you which of the following three things I did may have made a difference, but I CAN tell you that doing the following FOR ME reduced the estimated time to copy 10.75 GB from TC to an attached USB drive from 151 hours to 3 hours:

Followed the link in the above post and change those settings using terminal
Connected via ethernet rather than airport
AND changed the multicast rate on my wireless to 11mbps

This latter probably is not relevant in this case, since my primary connection was ethernet, BUT both ethernet and airport connections were active (ethernet listed first).

I found a solution (thanks to some non-Apple.com forums), at least for my flavor of this issue: With my configuration ...

- 24" new iMac,
- TC 1GB
- AirPortExpress in WDS configuration for my old PPC Mac Mini

... the problem was apparently the (default) security setting of "WPA or WPA2 Personal" for the TC (and also AirPort Express). Following an advice from a non-apple forum, I changed this setting to ONLY WPA2 Personal. After some hick-up (TC talking to AirPortExpress), my network is working again. The major difference: I get now instead of 300KB/s some 3MB/s from the iMac to the TC/Disk - not great but given the distance of my iMac to the TC and what I want to do with it acceptable.

Now: While my configuration might be not 100% mainstream, it has normally only Apple Hardware in it. However, I occasionally use an XP Laptop from work and a Linux Notebook that might have tried to connect as WPA, not WPA 2, in some point. I guess, that a similar situation might occur with someone having a second wireless router / other computers involved that try to use WPA when the choice is given.

Before I post this, I connected with both my windows lapto and the Linux laptop, no change in performance.

Good luck and Cheers,
B.