[wplug] Fwd: Delivery Status Notification (Failure)

[David J. Pryke]

Mackenzie Morgan wrote:
> On Friday 19 June 2009 6:38:46 am Zachary Uram wrote:
>> What is CAT6 cable used for?
> 
> Same thing as CAT5, but I think it can go longer distances without degradation 
> of signal.
> 

Actually, I believe the 100m maximum length limit applies to CAT6 as well - 
it has to do with the time it takes for the electrons to travel 100m and the 
fact that round-trip time of a packet of information would exceed the time a 
switch would "wait" for it if you exceed 100m by too much.  (100m is, of 
course, a standard and can be adjusted in small amounts in specific cases, 
but it is best not to exceed it.)

The CAT5e standard dictates that the cabling must be able to carry traffic 
at 100MHz, which does allow us to get to 1Gbps.  The CAT6 standard dictates 
that the cabling must meet 250MHz as a minimum.  This allows greater speeds 
than CAT5e.

CAT6 will, by design, be more "resistant" to external interference (like 
power lines) than CAT5e when running at the same speeds as CAT5e. (Like 10, 
100, or 1000Mbps.)  And, while CAT5e can support gigabit speeds, CAT6 is 
*certified* for gigabit speeds.  (This is mostly relevant to the 
interference rejection/resistance.)

Ine of the biggest issues to be aware of in network cabling is NEXT (Near 
End CrossTalk.)  NEXT is electrical interference between the pairs in a 
cable, or pairs in an adjacent cable, at the "Near end" connector on testing 
equipment, meaning, the connector that is plugged into the test unit when 
testing.  The standards for CAT6 regarding NEXT are more stringent than 
those for CAT5 & CAT5e.  This is relevant to the fact that CAT6 is certified 
to operate at 250MHz vs. the 100MHz of CAT5e.

Read more at the following links:
http://www.dslreports.com/faq/5010
http://discountcablesusa.com/ethernet-cables100.html
http://en.wikipedia.org/wiki/Category_6_cable

In general, for home or even small office use, CAT5e will more than suffice 
for most needs, even for years to come.  If you are planning a large 
installation with multiple switching tiers and high performance 
requirements, CAT6 would be a better choice.  But, if you are in the 
position to be planning an installation like that, you most likely know much 
more about the cabling standards than is expressed in this e-mail.

To sum up: Utilizing CAT6 is "future proofing" your network build, while 
using CAT5e is cost sensitive and usually good enough for installations 
where there is even a debate between using one versus the other.

Most of this is from the top of my head; I apologize if any of it is 
misleading or incorrect...it has been a while since I've dealt with the 
"nitty-gritty" of network cabling.  Everyone feel free to jump in with 
corrections as needed.

-- 
Thank you,

David J. Pryke