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Re: [802.3af] Category 6 cabling




James-
Bob-

I hope what Bob said is true.

It SHOULD be true that:
         1) Cat 6 and 7 cabling, in addition to meeting their own 
requirements also "meet or exceed" all of the requirements of Categories 3, 
4, 5 and 5e.

         2) That when plugging cabling together in a mixed fashion through 
physically compatible (i.e. RJ-45 form factor) connectors (e.g. Cat 5e work 
area cable plugged into Cat 6 infrastructure) the end-to-end cabling meets 
(at least) all of the performance requirements of the low category section.

Item #2 has been a problem in the development of higher category cabling, 
however the problems have not been at DC so I don't expect any problems 
with DTE Power.

The major problem that I would expect are the same old problems that we 
have had all along, that is that all of 802.3 UTP systems have been 
engineered for 100 Ohm 4-Pair Unshielded Twisted Pair. World wide generic 
cabling implementations (supported by ISO/IEC 11801) include:
         1)      120 Cabling
         2)      4 conductor cabling instead of 8 conductor
         3)      Quad construction instead of twisted pair
         4)      Shielded instead of unshielded cable construction
         5)      Pinouts for 4 conductor that don't support Ethernet

Cat 6 and Cat 7 standards are solutions in search of a problem that has yet 
to present itself to the market. If an Cat 6 and/or Cat 7 installation is 
specified to also have to meet Cat 5e requirements (as it should be so that 
it is actually useful for something) then there should be no problem.

In the midst of all of this morass I expect that lack of support for DTE 
Power will tend to be the least of the problems. That does not mean that 
there won't be something on the list that will bite, somewhere, sometime.

I hope this helps.

Geoff

At 12:53 PM 5/16/02 -0400, Robert D. Love wrote:

>James, I believe that Categories 6 and 7 both meet all Category 5 cable
>requirements (except for the physical shape of the Category 7 connector).
>Therefore, any technology that can run over Category 5 (and 5E) cabling,
>should also run over Categories 6 and 7 cabling.
>
>Best regards,
>
>Robert D. Love
>President, Resilient Packet Ring Alliance
>President, LAN Connect Consultants
>7105 Leveret Circle     Raleigh, NC 27615
>Phone: 919 848-6773       Mobile: 919 810-7816
>email: rdlove@xxxxxxxx          Fax: 208 978-1187
>----- Original Message -----
>From: "James M. Polk" <jmpolk@xxxxxxxxx>
>To: "McMillan, Paul" <Paul.Mcmillan@xxxxxxxxxxxxxxx>;
><stds-802-3-pwrviamdi@xxxxxxxx>
>Sent: Wednesday, May 15, 2002 1:38 PM
>Subject: Re: [802.3af] Category 6 cabling
>
>
> >
> > Paul
> >
> > I believe 100BASE TX is written to Category 5. The same I believe is true
> > for GigE. Cat 6 and 7 aren't written into either spec... so I don't know
>if
> > the IEEE has a charter to address this (them?) directly, but is likely
> > deemed 'out of scope' since a non-conformant infrastructure is being used
> > in either case...
> >
> > I could be wrong here though
> >
> > At 09:57 AM 5/15/2002 -0700, McMillan, Paul wrote:
> > >
> > >Hello All,
> > >
> > >As a follow on question that I made earlier, Has anyone been faced with
> > >potential warranty issues from cabling manufacturers? Specifically,
> > >manufacturers referencing channel to channel certification being voided
>if
> > >power is applied over the cabling infrastructure. This is specific to a
> > >category 6 wiring implementation.  This leads to a more obvious question
> > >which is everything I have read on the 802.3af specification references
> > >category 5 cabling. I assume the category 6 or 7 cabling is addressed.
> > >
> > > Regards
> > >Paul McMillan
> > >Solutions Architect
> > >CCDA
> > >Siemens Enterprise Networks
> > >Penn-Jersey Region
> > >RNET 590-3527
> > >Outside (610)-660-3527
> > >
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> >
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> >
> > James M. Polk
> > Senior Consulting Engineer
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