Subject: How does wu-ftpd handle connections?

From: Jason Kawamura <[email-masked]>
Date: Wed, 1 May 1996 11:55:41 -0700 (PDT)

I haven't gone through all the code for the daemon, but I have a 
question I hope someone has the answer to.  How does wu-ftpd handle the 
connections?  In other words, if there are 50 connections ranging from T3 
access to the internet to a 14.4 dial-up PPP account, how does wu-ftp 
handle the throughput to them?  Will the T3 get most of the bandwidth 
while the 14.4 PPP gets the scraps?
     I'm trying to determine why our ftp server is getting so many 
complaints about it's slowness when our hardware and connection isn't the 
problem (sparc 20 with 256MB RAM and a T3 to the internet).  We have 
notice that we sporadically saturate out 10BaseT interface but we haven't 
hit our limit of 50 concurrent connections.
     How do large sites handle many connections and not sacrifice too 
much speed?  We'd like to up our concurrent connections to about 
150-200.  Do we need to change our hardware configurations any?  Or do we 
need to tweak our ftp server?  And if so...how?
     Thanks in advance for listening to my ramblings.  I'd appreciate any 
help you can give me.

                    Jason Kawamura

---

From: Herman Weaver/IS/CCC <[email-masked]>
Date: 1 May 96 14:56:43 EDT

Jason,

First off, it seems like your botttleneck is the 10BASE T connection to your 
Sparc20.  The T3 connections
can only communicate as fast as your slowest link(i.e. the 10BASE T)  So that 
means you are only getting
about 10 MB/s (theoretically; you will really get only 5 - 7MB/s) of throughput 
to any ftp session
no matter what the speed is.  Obviously a 1400 PPP connection is going to be 
slower than a T3.    If you are already seeing 
periods where the 10BASE T is saturated, then you should probably explore how 
that link is getting filled
up like large file download or other internal user loads.  Wu-ftpd does not 
manage ethernet loads or balancing, nor
is it concerned with the speeds of the connections made to it.  It really has 
no way of knowing that stuff.  It will transmit
as fast as the link will allow.

Hope this helps,

Herman Weaver
Network Systems Engineer
CCC Information Services

To: wu-ftpd @ wugate.wustl.edu @ Internet
cc:  (bcc: Herman Weaver/IS/CCC)
From: jason @ ten.net (Jason Kawamura) @ Internet @ FSC
Date: 05/01/96 11:55:41 AM
Subject: How does wu-ftpd handle connections?

                    Jason Kawamura