Subject: Re: TCP/IP tuning.
To: Thomas Miller <tom@insolvencyhelp.org>
From: Richard Rauch <rkr@olib.org>
List: current-users
Date: 03/02/2004 10:12:13
Hm...I didn't think that I Cc'ed the original message to the list.
There's nothing all that useful to the list in this.  (^&  Ah well.

 [...]
> >  * The idea about using multiple connections is a good way to test
> >    your real performance.  
> 
> David's idea.  :-)

Well, I suspect that, to be honest, many have recreated the idea
independantly in the past.


> >    But multiple connections to a SINGLE HOST are
> >    more likely to be throttled (by that host).
> 
> Hmm.  It seems like a lot of extra work for a server 
> always to be keeping track of the sources of all the 

If it odesn't keep track of the sources of the connections, it
won't know to whom to send what, will it?  (^&  It's just a
little bit of extra bookkeeping to track the data rate.

In any case, I've seen people on here talking about using
NetBSD network throttling for just this purpose.  (They already
have per-connection throttling, but felt upset when a single
user made multiple connections, supposedly to get N*M throughput,
where N is the number of connections and M the throughput per
connection.  They wanted to be able to rewrite that formula as
N*(M/N) so that users end up with no more than M throughput, total,
no matter how many connections they use.)


 [...]
> > My personal opinion is that 5Mbits/sec is far enough ahead of the
> > curve for general Internet users (ignoring large businesses, educational
> > institutions, etc.) that you will find it hard to see that kind of
> > performance in practice.
> 
> I think, if the ISP sells "up to 3 Mbps" and also "up to 
> 5 Mbps, then it's reasonable for the customer to assume 
> that she should be able to download at something approaching 
> the rated speed at least occasionally.  Otherwise, they 
> could just as well sell the connection as "up to 100 Mbps" 
> or "up to 1000 Mbps."  

Your cablemodem is probably not physically capable of that.  Nor
are they likely to be even theoretically pumping that many bits per
second down to just one user, even if your modem supported it.

5Mbits/sec, however, is theoretically achievable with your situation
(I assume).  I just wouldn't count on seeing it on single connections
to single systems.  But, if you have multiple users in your home,
that extra 50% or so bandwidth may make things easier when multiple
users are trying to surf the web at once.  And you may have
times when you get that 5Mbits/sec to a single site, even.


-- 
  "I probably don't know what I'm talking about."  http://www.olib.org/~rkr/