[K12OSN] Re: Networking a new school for K12LTSP?

[Robert Arkiletian]

On 1/31/07, Robert Arkiletian <robark at gmail.com> wrote:
> On 1/31/07, Petre Scheie <petre at maltzen.net> wrote:
> > Terrell Prudé Jr. wrote:
> > > Robert Arkiletian wrote:
> > >> On 1/29/07, Joseph Bishay <joseph.bishay at gmail.com> wrote:
> > >>> Hello,
> > >>>
> > >>> I hope you are doing well.
> > >>>
> > >>> Thank you all for the comprehensive reply!
> > >>>
> > >>> Once I started reading your email, I realized that probably the best
> > >>> way to proceed was to work with the idea of NIC Bonding or port
> > >>> trunking.  I have a surplus of Gigabit cards so I could put 3 in a
> > >>> server (reading online I found that more than 3 wasn't going to give
> > >>> enough of an improvement due to the PCI bus limitations -- can anyone
> > >>> validate this?) and then send all 3 of those to the switch. I could
> > >>> then bond 3 ports from that switch to the next one (we'll probably
> > >>> have 2 x48 gigabit switches for the whole building -- still counting
> > >>> the number of ports/computers required) so as to deal with the
> > >>> bandwidth.  The cost of some of those fiber <-> copper converts look
> > >>> rather daunting.
> > >>>
> > >>> I would VERY MUCH prefer to use only 1 server for the entire building
> > >>> -- I am still very much a novice at this and the complexities of
> > >>> setting up multiple servers or splitting into application & /home with
> > >>> LAPD sounds rather daunting.
> > >>>
> > >> If your still set on one server also have a look at this
> > >> http://k12ltsp.org/mediawiki/index.php/Technical:Subnetting
> > >> Instead of port trunking I think this would be a better idea.
> > >> Especially if you are going to have 2 48 port switches that could be
> > >> on different gigabit linked subnets.
> > >
> > > Hmm...I hadn't thought of that particular application myself--addressing
> > > bandwidth bottlenecks--but you're right, that sure would do it!  That
> > > never even occurred to me...thanks!
> > >
> > > --TP
> > I recall reading somewhere that three gigabit cards is probably the max that the PCI bus
> > can handle.  Can anyone confirm or deny this?
>
> No. A gigabit card is 1 Gibabit/s (that's 1 billion bits per second).
> Each byte is 8 bits. So  it maxs out at 125MB/s. A simple PCI bus can
> handle 133MB/s max. So 1 gigabit ethernet card can saturate a PCI bus

Correction:
PCI 2.2 spec is 32 bits at 66Mhz which equals 266MB/s.  So 2 gigabit
nics should be able to saturate it. The original PCI bus was 32bits at
33Mhz which is 133MB/s.

-- 
Robert Arkiletian
Eric Hamber Secondary, Vancouver, Canada
Fl_TeacherTool http://www3.telus.net/public/robark/Fl_TeacherTool/
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