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

[Robert Arkiletian]

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
(remember other devices are probably sharing the PCI bus). That's why
not many manufacturers make gigabit pci nics. What you want is PCI-X
or now we have the newer PCI-E. Server boards still use PCI-X as PCI-E
is too new.
See this
http://en.wikipedia.org/wiki/List_of_device_bandwidths

>
> (BTW, thanks to Terrell for providing the text of the wiki page on subnetting.)
>
> Petre
>
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-- 
Robert Arkiletian
Eric Hamber Secondary, Vancouver, Canada
Fl_TeacherTool http://www3.telus.net/public/robark/Fl_TeacherTool/
C++ GUI tutorial http://www3.telus.net/public/robark/