[Tfug] Cabling

[Louis Taber]

When IBM moved equipment in a computer center with channel cables, the
cables were often just left in place.  It was simply too difficult to
remove them.  My recollection has each of the dual cables being about 1.5
inches in diameter.


On Sun, Dec 1, 2013 at 12:31 PM, Bexley Hall <bexley401 at yahoo.com> wrote:

> Hi Louis,
>
> On 12/1/2013 7:11 AM, Louis Taber wrote:
>
>> Would mounting a switch or two under the benches help keep the confusion
>> down?
>>
>
> That's what I have, currently.  Previously, a pair of 8 port switches
> now replaced by a single 16 port.  The "uplink" from the switch
> leaves the room via one of the RJ45's in the wall.  (most traffic
> is *within* the room though some of the printers are in another
> room so need a way *out*)
>
> My work area resembles a large "U" -- ~6.5' "tall" and ~11' "wide".
> The tables are 32 in deep (front to back).  So, there's about 4.5'
> between the "uprights" of the U -- which is where I sit.
>
> Quick math shows the outer perimeter is ~24 ft (6.5+11+6.5) while
> the inner is about 12.5 ft.  (this is important as it affects
> the placement of kit and wire)
>
> The equipment below the tables must all be accessible from that
> 12.5 ft of "front exposure".  Network cabling hangs from the
> *back* edge of the tables (so you don't have to reach *past*
> it as you grope around under the tables -- and, don't have
> wires peeling off the bundle in front of kit!).
>
> Not counting the switch, there are 14 drops in that 12.5' span.
> Of course, some are on top of the tables while others beneath.
> So, there are lots of different cable lengths involved/required
> (if you don't want to have "slop" dangling somewhere).
>
> Originally, I had run the cabling on the floor, along the walls.
> But, this just leaves a big snarl of wire -- all the network
> cables that are trying to get to the switch (which is why I had
> two smaller switches, previously -- split the "congestion").
>
> Plus, the power cords that feed the various outlet strips and
> UPS's.
>
> Plus the video cables that connect machines (below) to displays
> (above).
>
> Plus the SCSI cables that connect to external drives, transports
> and scanners.
>
> Plus the serial cables for EPROM programmer, digitizing tablet,
> motion controller and a few "serial consoles" for headless boxen.
>
> Plus the USB cables for keyboards, mice, scanners, camera and printers.
>
> And, the few audio cables to tie in PMP, etc.  (don't forget how
> many of these devices have wall warts or bricks!)
>
> Letting *everything* sit on the floor just made it impossible to
> plug/unplug *anything* -- power, comms, etc.
>
> So, it was relatively easy to get the power strips mounted to the
> undersides of the tables.  Then, select short power cords to
> eliminate "pools" of power cabling on the floor behind machines.
>
> Network cable was similarly easy to get fastened above.  Both of
> these tend to see the most "need for access" so getting them out
> of the ratsnest was a quick win.
>
> The remaining cables are too "specific" to do much about.  E.g.,
> there's no slop (allowed) in a SCSI cable so it's pretty much
> point to point -- put host *here*, peripherals 18 inches away!
> Monitors gotta go where monitors gotta go so no real choice
> there.  I've tried to route individual serial devices to fixed
> locations even though it means I have to access the associated
> device from a particular machine, etc. (e.g., the EPROM programmer
> is tethered to my "engineering" workstation; serial console for
> database server hangs off an X terminal, etc.)
>
> Problem is trying to make an Engineering *Department* fit in a
> single *office*!  :<
>
>
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