Re: [SQU] Performance Question

Sort of a similar thing.

By turning on TCP header compression you increase the effective
utilization of the link by sending more data in less bits.

By running proxies on machines with good TCP implementations, satellite
(or other very high latency high bandwidth) users can increase the
effective utilization of the link by having a larger TCP window to keep
the data flowing and correctly tuned retransmission timers to not have
unneeded retransmissions only due to the high latency.

Then you also have the interesting topic of proxies applying transport
transformations of the data. Such as compression. This can even further
increase the effective utilization of the link. There is a experimental
patch implementing such things in Squid (and yes, HTTP allows for it,
and it is even covered by standards)

What you need to keep in mind for all those approaches is that there
must be a proxy on both sides of the link for most of this, just as
there must be support for compressed TCP headers at both sides..

--
Henrik Nordstrom
Awie wrote:
> 
> Wow......I become jealous to hear Audie's download rate. I only use 128 Kbps
> through VSAT that (maximum) run at 10 KB/s to download.
> 
> Henrik,  it is interesting to read your email that having proxies can
> increase the utilization of the link.
> 
> I configured my router to have TCP Header compression that increase its CPU
> 2%-3%. But I can save bandwidth for around 10% - 20%. (Sorry, it perhaps has
> no relation with Squid discussion)
> 
> Please advise. Thx
> 
> Best Regards,
> 
> Awie
> awie@eksadata.com
> PT. EKSADATA INTISOLUSI
> Phone   : (62-361) 261514
> Mobile1 : (62-82) 3610369
> Mobile2 : (62-818) 346241
> ----- Original Message -----
> From: "Henrik Nordstrom" <hno@hem.passagen.se>
> To: "Audie Pierre" <audiep@vescomamerica.com>
> Cc: <squid-users@ircache.net>
> Sent: Tuesday, October 31, 2000 5:38 AM
> Subject: Re: [SQU] Performance Question
> 
> > Audie Pierre wrote:
> > >
> > > Hi! All,
> > > If I am downloading @ 80Kb/s  without the SQUID proxy server. Does
> > > anyone know what the download speed should be approximately with SQUID.
> > > What is acceptable and what is not?
> >
> > 80Kb/s. Acceptable variance (except on cache hits) is plus minus a
> > non-noticeable fraction. The exception is certain extreme types of links
> > (i.e. satellites) where having proxies can increase the utilization of
> > the link due to lack of capabilities in most client and server TCP
> > implementations and some other odd bieffects..
> >
> > --
> > Henrik Nordstrom
> >
> > --
> > To unsubscribe, see http://www.squid-cache.org/mailing-lists.html
> >
--
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