[ale] Choke point (or when to bring on router)

[Bao C. Ha]

A 25-Mhz 486 can do a T1 or 2,3,4 T1s easily!  A T3 is only
45 Mbits/s full-duplex.  You will need to go to ATM/Sonnet
speeds before you will see a stall in Linux.

A Cisco is better in pushing packets, not because its CPU
is faster, but rather its backplane can handle a lot more
bandwidth.  PCI is the bottleneck for PC-based high
speed transfers.

In the router's world, we usually talk about processing
limit because these Ciscos are too sucky in processing
BGP4 tables.  These Pentium II/III/IV have too much CPU
that it is not even a concern.  About 4 years ago, even
the 33-Mhz 486 in one of the Livingston's Portmasters can
converge a BGP4 table while you would need a mid-end 
Cisco 3640 to barely do it. 

Bao

> -----Original Message-----
> From: Transam [mailto:transam at cavu.com]
> Sent: Wednesday, March 20, 2002 12:32 PM
> To: krugerb at benning.army.mil
> Cc: ale at ale.org; dhurst at kennesaw.edu
> Subject: Re: [ale] Choke point (or when to bring on router)
> 
> 
> > Have you looked at adding intelligent NICs to offload 
> processing a bit? 
> > that way you could keep the advanced routing techniques 
> only available
> > thru linux but not overload your machine.  Just saw an ad 
> or article in
> > a Jan Linux mag about this.  Showed an NIC with a small 
> RTOS that took
> > care of alot of processing.  You have to have a 2.4.x kernel.
> 
> > Dow
> 
> The guidline I've heard is that a decent Pentium (800 MHz or better)
> with Linux can keep up with a T3 with no trouble (unless you're doing
> VPN or very complex IP Chains/IP Tables rules).  Even a 100 MHz 486
> will keep up with T1.
> 
> Of course, doing the actual measurements over a direct 100 
> Mbaud network
> isn't a big deal to do.
> 
> Bob Toxen
> transam at cavu.com                       [Bob's ALE Bulk email]
> bob at cavu.com                           [Please use for email to me]
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> 
> > Bob Kruger wrote:
> > > 
> > > Folks;
> > > 
> > > Got a couple of questions for those who run large 
> throughput capacity
> > > systems as a router and a firewall.
> > > 
> > > At what volume of traffic would you consider replacing a 
> Linux box that
> > > serves as a router and firewall and replacing it with 
> dedicated hardware
> > > like a Cisco?  Does anyone have any tips on tweaking a system to
> > > maximize throughput?
> > > 
> > > Regards - Bob Kruger
> > > 
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> > -- 
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