[Click] Click performance

[Sheetalkumar Doshi]

Hi Eddie, Robert


>>Sheetal,

>>How fast can you send packets over the Orinoco cards without Click,
using the ordinary IP stack?

I get RTT's from pings around 2/3ms without click.. When I run the click router
in userspace I get around 10ms on laptops but around 30ms on Soekris boards
which are 486 based with 64MB ram.

>>What packet size are you using?

For pings I use 64Bytes as well as 1400 bytes. Surprisingly I seem to get the
same processing rate for both sizes


>>If your wireless link runs at 1 megabit/second, you would only be able
>>to send 89 1400-byte packets per second.

>>It is also true that some 802.11 cards have very inefficient bus
>>interfaces (i.e. no DMA), though the limits we've seen are a few
>>hundred packets per second, not < 100.
>>Robert


In the meantime to improve performance I decided to get click running as a
linuxmodule. I used a 2.4.18 kernel with a 1.2.4 version of click initially on
the soekris box ( 486 Mhz cpu 64MB RAM). What I saw was that ping RTT from the
laptop to the soekris reduced drastically from 30 ms in userlevel to 5-8 ms in
kernel space. However when i originated the pings from the soekris box to the
laptop, the RTT increased to 100ms. I'm guessing that click is somehow hoarding
the cpu on the soekris. I even migrated to 1.3 version of click and enabled the
adaptive scheduling, which then resulted in the soekris box hanging up on me
when i started the router and pinged it from a laptop. Do you think that the
cpu hoarding of click could cause this to happen? Any remedies you could
suggest?

Thanks and Regards
Sheetal

--
Sheetalkumar Doshi
PhD Student/Research Assistant
Dept. Of Electrical and Computer Engineering
University of Colorado at Boulder
http://ucsub.colorado.edu/~doshi