[rescue] Re: 20th Anniversary Mac

Gavin Hubbard ghub005 at xtra.co.nz
Thu Feb 6 18:09:59 CST 2003


Copper did make it into the first GigE spec, however the cabling is co-ax
not UTP/STP. The implementation that I saw was a series of short
point-to-point links between stackable switches e.g. an external backplane.
IIRC the switches I saw were made by Intel.

Google should be able to pull up some info on the 1000Base-CX specification.

Regards,

Gavin


>Are you sure someone didn't just steal fc-al GBICs and plug em into gig-e
>gear for that 1000BaseCX?  fc-al gbics will work just fine, and happen to
>use just the connector you describe, but I was nearly 100% sure copper
>never made it into the original gig-e spec, and they had to go from 2 pair
>to 4 pair for the later spec..
>	Nick
>
>On Thu, 6 Feb 2003, Gavin Hubbard wrote:
>> There are actually two different kinds of GigE over copper wiring systems.
>> The initial GigE spec (IEEE 802.3z) was released in 1998 and didn't include
>> UTP because there were a lot of technical issues to sort out. The copper
>> implementation they chose back them is called 1000BaseCX and it runs over a
>> 150-Ohm balanced & shielded copper cable. I have only ever seen it on one
>> site - it is quite distinctive as the interface connector is a DB9. The
>> maximum cable run of 1000BaseCX is only 25m. 
>> The GigE over UTP spec (IEEE 802.3ab) was released several years later and
>> as Shawn has said, has a maximimum cable run of 100m.
>> Regards,
>> Gavin
>------------------------------


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