[188261] in North American Network Operators' Group
Re: DataCenter color-coding cabling schema
daemon@ATHENA.MIT.EDU (Owen DeLong)
Sun Mar 13 20:11:33 2016
X-Original-To: nanog@nanog.org
From: Owen DeLong <owen@delong.com>
In-Reply-To: <CABtQX6EGR03VG9CQ+Bc6n3QXzQD28GLPh4diD6oxyZrdZ0vhiw@mail.gmail.com>
Date: Sun, 13 Mar 2016 17:10:26 -0700
To: Yardiel Fuentes <yardiel@gmail.com>
Cc: "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
I don=E2=80=99t know of any universal standards, but I=E2=80=99ve 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 =E2=80=94 Multimode Fiber
Yellow =E2=80=94 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=E2=80=A6 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=E2=80=99ve 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=E2=80=99ve prevented a serious outage by giving =
the port number to the remote
hands guy and then insisting that he read me the cable ID. =E2=80=9CNo, =
try the other port
FE-0/2/4=E2=80=A6 You=E2=80=99re off by one. It=E2=80=99s =
above/left/right/below you.=E2=80=9D
[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=E2=80=99s 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=E2=80=99re most likely going to either get orange =
multimode or yellow
singlemode and that=E2=80=99s just the way it is.
Owen
> On Mar 12, 2016, at 11:11 , Yardiel Fuentes <yardiel@gmail.com> wrote:
>=20
> Hello Nanog-ers,
>=20
> Have any of you had the option or; conversely, do you know of =E2=80=9Cb=
est
> practices" or =E2=80=9Ccommon standards=E2=80=9D, 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 ?=E2=80=A6. =
Yes, this is
> actually considering paying for customized color-coded cabling in a =
Data
> Center...
>=20
> Mr. Google did not really provide me with relevant answers on the =
above=E2=80=A6
> beyond the typical (Orange is for MMF, yellow for SMF, etc)=E2=80=A6
>=20
> Any reasons for or against it welcome too...
>=20
> --=20
> Yardiel Fuentes
