[K12OSN] Gigabit headach

Tue Aug 31 23:44:12 UTC 2004

Then you'd better bring the folks who did the cabling back in and tell 
'em to actually follow the Cat5 specs this time.  You may wish to float 
the insinuation of possible legal action if they buck.  IEEE 802.1ab 
says quite explicitly that 1000BaseT will work across existing Cat5-spec 
wiring plants.  There was a similar problem back in the 1990's, when 
100BaseTX was first getting deployed.  Some cabling installers cut 
corners and used Cat3 RJ-45 plugs and even Cat3 patch panels during 
their "Cat5" installs!  Of course, this completely broke the 100Mb 
connectivity.  As you can imagine, there was--umm, more than one lawsuit 
over this.

 From what you're saying, you're going to have this problem no matter 
whose Gig-E copper switches you buy.  The spec is the spec.

Another option is to run some fiber links and get some mini-GBIC modules 
from Amer.com.  I've used their fiber modules with success, so I know 
they work.  This afternoon, I also did a 1000BaseT (i. e. copper) 
connection from a spare SR48G2i switch to my Catalyst 3550 and pumped 
about 600Mb of traffic across it w/ no errors (multiple ISO image FTP 
transfer), so now I _know_ that 1000BaseT on those switches does indeed 
work.  Unless you need GVRP support (you'll know if you do), you made a 
good purchase.

--TP

Shane Stafford wrote:

>oh knowing who did our cabling and the fact we just purchased 5 of these
>switches, this is not a good thing.
>
>ah well, life stays interesting
>
>Shane
>
>"Support list for opensource software in schools." <k12osn at redhat.com> on
>Tuesday, August 31, 2004 at 7:12 PM -0500 wrote:
>  
>
>>On Mon, 2004-08-30 at 22:46, Duane Wilson wrote:
>>    
>>
>>>I took everyones advice and bought the amer.com  SR24G2.
>>>
>>>Installed it between server and terminals.
>>>
>>>Tried to boot terminals all at once - nada!
>>>    Would not even get DHCP
>>>
>>>Tried one terminal.
>>>    Got DHCP but choked on 'loading vmlinuz'
>>>
>>>There is about 230 ft. of cat Ve from the server to the AR24G2.
>>>
>>>Is that too far?
>>>Did I crimp the end wrong?  (It works fine when connected to the old
>>>      
>>>
>>100 
>>    
>>
>>>Mbit)
>>>Is my switch bad?
>>>
>>>Anyone???
>>>
>>>
>>>Thanks,
>>>Duane Wilson
>>>
>>>
>>>      
>>>
>>I agree with Terrell.  The tolerances for Gig vs 100mb are substantial. 
>>Just because it works with 100mb does *not* mean it will work with gig. 
>>Take it from a person who has already gone through what you are going
>>through.  Check your cabling.  It has to be done *perfectly* for gig to
>>work over copper.
>>
>>Jack
>>
>>
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>>    
>>
>
>
>
>Shane Stafford, MCSE, MCT
>Director Information Services Glenburn School and Town
>Educational System Integrator/Network Engineer
>S & B Consulting
>
>
>_______________________________________________
>K12OSN mailing list
>K12OSN at redhat.com
>https://www.redhat.com/mailman/listinfo/k12osn
>For more info see <http://www.k12os.org>
>
>  
>

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