David Malone writes:
> As Padraig mentioned, WiFi has pretty big per-packet overheads: you
> pay for two PHY headers, one for the packet and one for the MAC
> ACK. In 802.11b that can be an additional 192 or 384us in an overall
> cost of ~1400us for 1500 byte 802.11b packet. Naturally, this is
> much worse for small packets. I would guess that making sure that
> NFS sends big packets whenever possible is important. The large
> rsize and wsize should help with this, but you'll still get small
> requests followed by large responses - I don't think there is a lot
> you can do about this.
>> If any of your WiFi hardware supports putting two packets in one
> MAC frame (the Atheros drivers support this - I think they call it
> "fast frames" or somesuch), then that might help a bit. I've never
> tested this to see how effective it is.
>> We have some nice performance improvements to TCP over wireless,
> but mainly for the situation where you have multiple wireless
> clients. (Which reminds me, it might be worth turning the Linux
> frto stuff on, but YMMV).
That's
sudo sysctl net.ipv4.tcp_frto=1
? I'll give it a go. (Worth turning on for all my wireless clients I'd
guess...)
--j.
Maintained by the ILUG website team. The aim of Linux.ie is to
support and help commercial and private users of Linux in Ireland. You can
display ILUG news in your own webpages, read backend
information to find out how. Networking services kindly provided by HEAnet, server kindly donated by
Dell. Linux is a trademark of Linus Torvalds,
used with permission. No penguins were harmed in the production or maintenance
of this highly praised website. Looking for the
Indian Linux Users' Group? Try here. If you've read all this and aren't a lawyer: you should be!
