[ale] OT: GigE Copper specs

[Matt Smith]

A punch down is any number of types of termination points for wire.  You often find "66" punch down blocks at the demarc point in a building.  Building wiring for networking is generally terminated to a patch panel via "110" punch down blocks... 

Basically you're talking about taking the cut, unsheathed ethernet cable and "punching" each of the individual conductors onto corresponding fingers of the block that both cut through the insulation to make electrical contact, and physically hold the wire in place.

--Matt


-----Original Message-----
From: Dow Hurst [mailto:dhurst at kennesaw.edu]
Sent: Friday, April 09, 2004 11:32 AM
To: freemyer-ml at NorcrossGroup.com; Atlanta Linux Enthusiasts
Subject: Re: [ale] OT: GigE Copper specs


May I ask what is a punch down?  Is that cutting the cable and adding a RJ-45 
connector?
Dow


Greg Freemyer wrote:
> On Wed, 2004-04-07 at 14:43, griffisb at bellsouth.net wrote:
> 
>>Hey all, had an off-topic question about Gigabit Ethernet specs. Is it supported on Cat 5 cable, patch panels and patch cords - or is Cat5e or better required. Distance is 100 meters, correct?
>>
>>I'm seeing a lot of errors on some GigE ports at work, and beleive it to be infrasture-related.
>>
>>_______________________________________________
>>Ale mailing list
>>Ale at ale.org
>>http://www.ale.org/mailman/listinfo/ale
> 
> 
> I don't know the details, but I do know that patch panel punch down
> techniques that work for 100 Mbit don't work for GigE.
> 
> For instance, with 100 Mbit it was not unusual to unwind several inches
> of individual wires near the punch downs.
> 
> With GigE, much tighter tolerances are needed for maintaining the
> twisted pairs all the way to the punch down.  (For some reason I'm
> thinking less than 6 inches of untwisted cable cummulative over the
> end-to-end connection.  If you are using multiple punch downs, then it
> adds up quickly.)
> 
> So, if you are doing punch downs (even if you have all GigE acceptable
> components) it is easy to mis-install patch panels, etc.
> 
> Greg

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