VERY(!) slow FTP sometimes

[Leon Pollak]

On Thursday, 15 בMay 2008, Till Straumann wrote:
> You should probably also say what RTEMS filesystem the files
> you are up/down-loading are residing on, how big they are
> etc.
The test file is about 1GB size.
File system is not RTEMS but our own. Measurements show that our performance 
is about 5MB/s sustained read.
I did not provide all this details as I thought that as my filesystem 
performance is much higher the details are irrelevant. Sorry, if this is not 
so...


> Also, you want to make sure the duplex settings are right
> on both sides.
Please, explain this more detailed.
The only "duplex setting" which I seem to know is the Ethernet Phy's duplex 
state. If this is the case, then - yes, PC's and RTEMS box are connected via 
the 100BT full duplex switch. I also checked cables to be standard.
As a double check, I also replaced the switch with 10BT HUB and saw about 30% 
less performance (about 320KB/s).

Hmm..... Well, I shall do the tests again with direct connection, although 
this is a good switch and no other connections....

Still, do you think that these details may explain the 7KB/s case?

And can you name some example figures of CPU+FTP sustained transfer rate?

> T.
Thank you!

> Leon Pollak wrote:
> > Hello, all.
> >
> > I incorporated the RTEMS ftpd to my MPC8247 at 150MHz based board with 100BT
> > FCC controller and made several main tests - everything seems to work
> > fine. I can upload/download files by Linux ftp client, FireFox in Linux
> > and IE in Windows.
> >
> > Now, when I decided to test the speed, I encountered the following VERY
> > strange numbers:
> > 1. IE as a client: in 100% of attempts the speed was about 14-16 KB/s.
> > 2. FireFox(Linux) as a client:
> > 	- in 90% of attempts the speed was about 400-460KB/s
> > 	- in about 10% - 7-8 KB/s.
> > Even in the "good" FireFox tests (above 400KB/s) the behavior looks also
> > strange a bit: it immediately starts at some number (once at 410KB/s,
> > then at 450KB/s, etc...) and does not change never more.
> >
> > 1. What may be the cause of the VERY low speed cases?
> > 2. Is the "good" speed really good for my case? Can somebody provide
> > numbers from his/her experience?
> >
> > Thanks.