nanog mailing list archives

Re: DataCenter color-coding cabling schema


From: "Aaron C. de Bruyn" <aaron () heyaaron com>
Date: Mon, 21 Mar 2016 12:44:41 -0700

That's a good reason to use it.  Who would cut it?  ;)

-A

On Mon, Mar 21, 2016 at 8:53 AM, STARNES, CURTIS <
Curtis.Starnes () granburyisd org> wrote:

Just to throw it out there but I always try not to use RED cable.
Normally, RED wire in any building is dedicated as FIRE system cabling.


Curtis Starnes
Senior Network Administrator
Granbury ISD
600 W. Bridge St. Ste. 40
Granbury, Texas  76048
(817) 408-4104
(817) 408-4126 Fax
curtis.starnes () granburyisd org
www.granburyisd.org



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-----Original Message-----
From: NANOG [mailto:nanog-bounces () nanog org] On Behalf Of Owen DeLong
Sent: Sunday, March 13, 2016 7:10 PM
To: Yardiel Fuentes <yardiel () gmail com>
Cc: nanog () nanog org
Subject: Re: DataCenter color-coding cabling schema

I don’t know of any universal standards, but I’ve used the following in
several installatins I was responsible for to good avail:

Twisted Pair:

RED:    Untrusted Network (Internet or possibly DMZ)
YELLOW: Optional for DMZ networks though I preferred to avoid documented
in [1] below
BLUE:   Trusted Network (back-end, internal, etc.)
GREEN:  RS-232 straight-thru
PURPLE: RS-232 X-Over (effectively Null Modem) 12345678 <-> 87654321 pin
map.
ORANGE: Ethernet X-Over (Best avoided documented in [2] below)
GREY:   Special purpose cabling not in one of the above categories

Fiber:
Orange — Multimode Fiber
Yellow — Singlemode Fiber

The absolute most useful thing you can do if you can impose the discipline
to update the cable map rigorously and/or allocate manpower for periodic
audits is to apply a unique serial number to each cable. I preferred to
document not only the cable ID, but also the length. For the installations
where I have worked, 5 digits was sufficient unique ID, so I used formats
like IIIII-L[.L] where IIIII was a unique ID and L.L was the length of the
cable in feet. (e.g. 00123-6.5 is cable number 123 which is 6.5 feet in
length).

The labels are (ideally) the self-laminating wrap-around types. I prefer
the Brady labeling system which will automatically print 2-4 (depending on
font size) instances of the label text on the self-laminating label such
that it can be read from virtually any side of the cable without requiring
you to rotate the label into view in most cases.

The Brady labeling system is a bit overpriced compared to the Brother
P-Touch, but the expanded capabilities and the quality of the label
adhesives and such is, IMHO, sufficiently superior to justify the cost.

Whatever you do, please do not use Flag labels on cables… I HATE THEM.
They are a constant source of entanglement and snags. They often get
knocked off as a result or mangled beyond recognition, rendering them
useless.

Similarly, I’ve found that circuit-ID and end-point labels on cables are
often ill-maintained, so if you do use them, please make sure you remove
them when the cable is moved/removed.

The length is very useful because it gives you a radius within which the
other end of the cable must be located and you can usually expect it to be
reasonably close to the outer edge of that radius.

More than a few times I’ve prevented a serious outage by giving the port
number to the remote hands guy and then insisting that he read me the cable
ID. “No, try the other port FE-0/2/4… You’re off by one. It’s
above/left/right/below you.”

[1] I prefer to avoid Yellow cables because some people have trouble
understanding that Yellow Fiber and Yellow UTP might have different
meanings. I also feel that the distinction between UNTRUSTED and DMZ
networks is usually not all that important in most cabling situations. YMMV.

[2] In this era of Auto-MDI/MDI-X ports and the like, it’s very rare to
encounter a situation that truly requires a crossover cable with no viable
alternative. If such is needed, I prefer to document it on the cable tags
rather than using a special color code. Again, you have the risk of people
not understanding that orange Fiber might not mean what Orange copper
means. YMMV

Yes, I know you can now get virtually any type of fiber in virtually any
color, but the simple fact of the matter remains that when you send skippy
out to buy emergency jumpers or such, you’re most likely going to either
get orange multimode or yellow singlemode and that’s just the way it is.

Owen

On Mar 12, 2016, at 11:11 , Yardiel Fuentes <yardiel () gmail com> wrote:

Hello Nanog-ers,

Have any of you had the option or; conversely, do you know of “best
practices" or “common standards”,  to color code physical cabling for
your connections in DataCenters for Base-T and FX connections? If so,
Could you share  any ttype of color-coding schema you are aware of ?….
Yes, this is actually considering paying for customized color-coded
cabling in a Data Center...

Mr. Google did not really provide me with relevant answers on the
above… beyond the typical (Orange is for MMF, yellow for SMF, etc)…

Any reasons for or against it welcome too...

--
Yardiel Fuentes




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