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Field guidesfor the work
The things people actually search for at eleven at night, answered properly: which colour goes on which pin, what a bridging clip does, how much twist you are allowed to lose, and what a finished switch configuration should contain. Interactive where a diagram beats a paragraph.
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Showing all 37
Cabling & low-voltage
Copper, glass,
pin by pin
Termination and specification work, with the colour codes rendered rather than described. Every diagram is interactive because the question is always 'which one goes here', and a picture you can flip answers it faster than a table you have to read twice.
- 015 steps
RJ45 Wiring: T568A and T568B
Both colour codes, pin by pin, side by side.
The two eight-position colour codes in full, with an interactive pinout you can flip between. Shows which pins actually move between A and B, which pairs carry data on 100 megabit versus gigabit, and how a crossover cable is built — plus why you almost certainly do not need one.
Who reaches for itAnyone terminating a plug or jack and wanting to be certain which colour goes where before they crimp.
Open - 025 steps
RJ11 Wiring and Phone Pinouts
Six positions, three lines, two colour systems.
The six-position telephone pinout, shown for one, two, and three lines. Covers both the old four-colour quad station wire and the twisted-pair equivalent used in modern work, explains tip and ring, and shows why lines number outward from the centre pair.
Who reaches for itAnyone terminating a phone jack, tracing a line in an older building, or working out why line 2 is dead.
Open - 035 steps
Keystone Jack Termination
Strip, seat, punch, snap — without failing the certification.
How to terminate a keystone jack so it certifies: how much jacket to strip, how much twist you are allowed to lose, which way the punchdown blade faces, and the handful of mistakes that account for nearly every failed test.
Who reaches for itAnyone landing outlets or loading a patch panel and wanting the run to certify first time.
Open - 046 steps
66 Block Wiring
Fifty rows, four columns, and where the bridging clips go.
How a 66 block is actually organised: which columns are bridged to which, where the incoming pairs land, what the bridging clips do, and how the 25-pair colour code maps onto the rows. Includes an interactive block you can step through pair by pair.
Who reaches for itAnyone working analogue telephone distribution in an older building, or tracing what a previous decade left behind.
Open - 056 steps
110 Block Wiring
Lay the pairs in, press the connecting block on.
The two-stage termination that confuses people the first time: conductors lay into the base in colour order, then a four- or five-pair connecting block presses over them and seats every contact at once. Covers lay-in order, connecting block sizes, and how the cross-connect is made on top.
Who reaches for itAnyone terminating horizontal cable onto a wall field rather than a patch panel.
Open - 06Reference
Cat5e vs Cat6 vs Cat6a vs Cat8
Speed, distance, and power decide it — not the bigger number.
What actually separates the twisted-pair categories, and how to choose between them. The answer is set by three things at once: the speed you need, how long the run is, and how much power the cable has to carry — a category that is right at 30 metres can be wrong at 90. Includes a selector that takes those three and tells you which cable to specify.
Who reaches for itAnyone specifying cable for a buildout, or working out whether what is already in the wall is good enough.
Open - 07Reference
Fibre Types, Connectors and Polish
Read the jacket, read the connector, don't mate blue to green.
Optical fibre is identified by colour on site the same way copper is: an aqua jacket means something specific and a green connector body means something you must not ignore. Covers OM1 through OM5 and OS2 with their jacket colours and real supported distances, the connector families you will actually meet, and the UPC/APC distinction that quietly kills links.
Who reaches for itAnyone patching a backbone, ordering optics, or trying to identify what is already terminated in the rack.
Open - 08Reference
PoE Standards and Why It Won't Power
The switch reserves the class, not the draw.
802.3af, at and bt in the terms that matter on site: what each class reserves from the switch against what actually reaches the device, which pairs carry the power, and the faults behind a device that will not power up — in the order worth checking them.
Who reaches for itAnyone hanging cameras or access points, or standing in front of a device with no link light and a switch that says it has budget.
Open - 09Reference
Camera Lens, Field of View and Pixel Density
Covering the room is not the same as identifying a face in it.
Choosing a lens is two questions, not one: how much scene fits in the frame, and whether there are enough pixels on a subject to be worth anything afterwards. Covers focal length against sensor format, and the DORI pixel-density bands that decide whether footage identifies somebody or merely shows that somebody was there.
Who reaches for itAnyone siting cameras and needing footage that will still be useful when somebody asks who that was.
Open - 107 steps
Cabling an Office Fit-Out
How many drops, run where, and what it takes to add one later.
Counting drops for a floor and planning the pathways they run in. Covers what actually needs a cable now that most devices are wireless, why the answer is still more than people expect, how to size containment so the next change is a pull rather than a rebuild, and where the telecom room has to be for the whole thing to certify.
Who reaches for itAnyone pricing or specifying cabling for a floor, and anyone being asked how many drops a new office needs.
Open
Mounting & physical install
Fixing things
to buildings
What is behind the surface, what will hold, and what the anchor is actually rated for. The part of the job where getting it wrong is measured in a repair to somebody else's wall.
- 017 steps
Mounting Displays on Any Wall
Find the structure. Everything else is a repair bill.
How to hang a display on the wall you actually have — timber stud, metal stud, concrete, block, brick, plaster over lath, and the demountable partitions that will not hold anything. Covers finding structure before drilling, matching the anchor to the substrate, why metal stud is the one that catches people out, and how to set height so the screen is comfortable to look at.
Who reaches for itAnyone hanging a screen in an office or meeting room and wanting it to still be there next year.
Open - 027 steps
Mounting IP Cameras
Height, angle, and the surfaces that ruin the picture at night.
Where a camera actually belongs and what stops the footage being usable. Covers mounting height against identification, the infrared reflection problem that makes an otherwise good install worthless after dark, weatherproofing and drip loops, cable entry and tamper resistance, and why the sun matters more than the lens.
Who reaches for itAnyone installing cameras and wanting footage that identifies somebody rather than footage that proves somebody was there.
Open
Testing & verification
Proving it
actually works
The half of the job that decides whether the rest of it holds. Finding a cable in a bundle of two hundred, reading the report that says the run passed, and choosing the instrument that produces it.
- 016 steps
Toning and Tracing a Cable
Finding one pair in a bundle of two hundred.
The method for identifying an unlabelled run with a tone generator and an inductive probe, and the reasons it goes wrong: tone bleeding onto neighbouring pairs, a probe held at the wrong sensitivity, and toning a live pair when you should not be. Covers copper pairs, data runs, and what to do when the tone is everywhere and therefore useless.
Who reaches for itAnyone standing in front of an undocumented bundle trying to work out which one goes to the jack they care about.
Open - 02Reference
Reading a Cable Certifier Report
What PASS* actually means, and which number to look at first.
A certification report is a compliance document. A pass sticker is not the same thing and will not survive an audit. This explains what each measurement is telling you — wire map, length, insertion loss, NEXT, PSNEXT, ACR-F, return loss and delay skew — which failures point at the termination rather than the cable, and why an asterisk beside PASS is not something to hand over quietly.
Who reaches for itAnyone handed a set of results to sign off, or holding a failure and trying to work out whether to re-terminate or re-pull.
Open - 03Reference
Which Cable Tester Do You Need?
Three tiers, and the one most people actually need.
Testers, qualifiers and certifiers solve different problems at very different prices, and the expensive one is not always the right answer. This lays out what each tier measures, what it cannot tell you, when renting beats buying, and what a small field operation genuinely needs in the bag versus what it should hire for the week it is warranting a floor.
Who reaches for itAnyone deciding what to put in the bag, or being asked for certification and working out whether to buy, rent, or subcontract it.
Open
Networking & wireless
The network,
layer by layer
Switching, addressing, and the radio side. What a configuration should contain when you hand it over, where the addressing behind it comes from, and how to read the network when something on it is broken.
- 01Reference
Subnetting, Explained
Where the numbers come from, and the meaning behind them.
Subnetting is one idea repeated: move the line between the network part of an address and the host part, and everything else follows. This walks the prefix bit by bit, in binary and in decimal, so the arithmetic stops being something you look up. Includes a worked example of carving a site into VLAN-sized blocks.
Who reaches for itAnyone who can use a subnet calculator but would rather understand what it is doing, or is carving up address space for the first time.
Open - 02Reference
The OSI Model, Layer by Layer
Seven layers, what each does, and how they hand off.
The OSI model is the seven-layer map every network conversation follows, from the application at the top to the wire at the bottom. This one is interactive: rotate the stack, click any layer, and see what it does, the protocols and data unit it works in, and how it hands off to the layers on either side of it.
Who reaches for itAnyone studying for a networking cert, learning where a protocol or device fits, or explaining the stack to someone else.
Open - 03Reference
Active Directory, Explained
Forests, domains, roles, and how a login really works.
Active Directory is the directory service a Windows network runs on — the forest and domain structure that holds every user, computer, and policy, and the roles and protocols that make a login work. This walks all of it interactively: explore the logical and physical structure, click through the five FSMO roles, see how Group Policy is applied, and step through the Kerberos exchange behind a single sign-on.
Who reaches for itAnyone learning Active Directory for a role or a cert, or mapping what they half-remember onto the parts that matter.
Open - 04Reference
Writing a Switch Configuration
From factory default to a switch you would hand over.
A configuration walkthrough in the order you actually do it: identity, management address, secure access, VLANs, access and trunk ports, spanning tree, then hardening. Every block is copyable and every line says why it is there rather than just what it does.
Who reaches for itAnyone commissioning a switch, or inheriting one and wanting to know what a complete configuration should contain.
Open - 056 steps
VLANs and Trunking
Access, trunk, tagged, native — and which one is the security hole.
What a VLAN actually does to a frame, the difference between an access port and a trunk, and why the native VLAN is the setting that turns a tidy design into a way onto another network. Covers tagging, allowed lists, voice VLANs, and the specific faults that look like cabling problems and are not.
Who reaches for itAnyone configuring a switch port and wanting to be sure what will and will not reach it, or diagnosing a device that links but has no address.
Open - 06Reference
Spanning Tree and Switching Loops
Why one patch cord can take a whole floor down in seconds.
What a switching loop actually does — and why it is instant and total rather than gradual — plus how spanning tree prevents it, how the root bridge gets elected, and the two port settings that turn an all-day outage into one dead port and a log line naming the culprit.
Who reaches for itAnyone who has watched a network die the moment somebody patched two ports together, and anyone commissioning a switch that should survive it.
Open - 07Reference
Reading a Traceroute
Which loss is real, and whose network it is in.
How to read traceroute, tracert and mtr output without drawing the wrong conclusion — which is the usual outcome. Covers why loss at one hop that does not continue is not loss at all, why a latency step that stays is distance rather than a fault, and why the last hop that answers is rarely where the problem is.
Who reaches for itAnyone holding traceroute output and about to tell a carrier the fault is theirs, or about to be told it is yours.
Open - 086 steps
DHCP, DNS and Helper Addresses
Why the new VLAN gets no addresses, and why it is always DNS.
How a device gets an address, why that stops working the moment you add a VLAN, and what a helper address does about it. Then the other half: what DNS is actually being asked, why resolution failures look like everything else, and the specific misconfigurations that produce a network which pings by address and fails by name.
Who reaches for itAnyone who has just created a VLAN and found nothing on it gets an address, or is staring at a machine that pings by IP and not by name.
Open - 097 steps
Wi-Fi Channel Planning and AP Placement
More access points at lower power, not fewer at maximum.
Why the instinct to turn the radios up and use the widest channels makes coverage worse, and what to do instead. Covers the three bands and what each is for, the trade between channel width and usable capacity, co-channel versus adjacent-channel interference, and where access points actually belong in a ceiling.
Who reaches for itAnyone placing access points on a floor plan, or trying to work out why a site with plenty of signal still performs badly.
Open
Voice & telecom
Tip, ring,
and what replaced it
Analogue lines and the SIP services taking over from them. The largest single share of the work we do, and the part with the most undocumented wiring and the most things that quietly stop working when somebody cuts over.
- 016 steps
POTS to VoIP: What Breaks
The lines nobody remembers until they stop working.
Carriers are retiring copper and the quotes make it look like a phone swap. It is not. The desk phones are the easy part — what catches people out is everything else that was quietly sharing those lines: the elevator, the fire panel, the alarm dialer, the fax that a regulator still expects to work. This is the survey to do before the cutover date, and what each of those lines actually needs instead.
Who reaches for itAnyone holding a carrier letter with a copper retirement date on it, trying to work out what is actually connected before the dial tone goes away.
Open - 026 steps
Testing an Analogue Phone Line
Tip, ring, and the four numbers that tell you whose fault it is.
How to tell a dead line from dead equipment, and an inside-wiring fault from a carrier fault, using a butt set and a multimeter. Covers on-hook voltage, loop current, ring voltage and the polarity check, what each reading should be, and what a wrong one means — including the readings that say the pair is shorted, open, or crossed with another line.
Who reaches for itAnyone standing at a block with a dead extension, trying to establish whether to call the carrier or keep walking the building.
Open
Endpoints & data
The machine,
and what is on it
Drives, encryption, and the recovery paths that only matter on the day they are needed. Written for the person holding a device that will not boot, or a disk that is about to stop.
- 01Reference
SMART Attributes That Predict Failure
A drive can report PASSED while it is visibly dying.
Which SMART numbers actually predict a drive failing and which ones people replace hardware over for no reason. Covers why pending sectors matter more than reallocated ones, why UDMA CRC errors are almost never the disk, what the NVMe health log reports instead, and why the drive's own self-assessment is set to protect a warranty rather than your data.
Who reaches for itAnyone holding smartctl output and deciding whether to image the drive tonight or schedule it for next quarter.
Open - 026 steps
BitLocker: Keys, Recovery and Escrow
The key exists somewhere, or the data does not.
What BitLocker actually protects against, why a machine suddenly asks for a recovery key when nothing was changed, and where that key should have been stored before it was needed. Covers TPM and the measured-boot triggers, the escrow options and how to verify one worked, suspending before firmware work, and what recovery looks like when the drive is pulled.
Who reaches for itAnyone facing a recovery prompt on a machine that was working yesterday, or rolling out encryption and wanting the keys to exist afterwards.
Open
Racks & rooms
What the room
looks like after
The part that decides whether the next person can work on it: how a rack is filled, and how every port is labelled so the label still means something in three years.
- 01Reference
Patch Panels and Labelling to TIA-606
A good label speaks a thousand words in only a few characters.
How to identify a cabling system so it is still readable when the person who installed it has gone. Covers the ANSI/TIA-606 identifier classes and what each level of the scheme names, the termination-field colour code, and a builder that assembles a compliant identifier from your own building, floor, room, rack and port.
Who reaches for itAnyone loading a panel, documenting a room, or inheriting a rack labelled in marker pen by somebody long gone.
Open - 02Reference
Rack Planning: Units, Depth, Weight and Heat
It fits vertically. That was never the hard part.
Four things decide whether equipment fits a rack, and height is the easy one. Covers rack units and what actually consumes them, usable depth against equipment plus cable management, static and dynamic weight limits, and the heat load a full rack throws — with a planner you can fill and check.
Who reaches for itAnyone specifying a cabinet, filling an IDF, or trying to work out why the room at the end of the corridor is always warm.
Open - 036 steps
Cable Management for Desks and Racks
Tidy is a by-product. Serviceable is the point.
How to dress cable under a desk, in a comms room, and in a rack, without creating something the next person cannot work on. Covers service loops, bend radius, hook-and-loop versus zip ties, why copper and fibre want different treatment, and the honest answer to whether fibre should be bundled at all.
Who reaches for itAnyone dressing a rack or a desk who wants it to still make sense in three years, and anyone inheriting one that does not.
Open - 04Reference
Grounding and Bonding a Telecom Room
One ground, one path, and no loops between rooms.
Why a comms room needs a deliberate bonding scheme rather than whatever the rack happened to touch, and what goes wrong without one. Covers the busbar and the backbone that ties rooms together, why a shield bonded at both ends can become an antenna, where hum and unexplained noise actually come from, and the difference between grounding for safety and bonding for signal.
Who reaches for itAnyone building out a telecom room, or chasing hum, noise, and faults that move around a building for no visible reason.
Open - 056 steps
UPS Sizing: VA, Watts and Runtime
The number on the box is not the number you need.
Why a 1500 VA unit does not deliver 1500 watts, how runtime actually behaves as load rises, and what belongs on battery in a comms room. Covers the power factor everyone trips over, sizing for the whole path rather than one device, why runtime curves are not linear, and the maintenance item that makes half the installed base useless.
Who reaches for itAnyone specifying a UPS for a comms room, or working out why the one already there does not last as long as the box promised.
Open
Field operations
Running the job,
not just the work
Sequencing, access, and handover. The parts that decide whether a floor opens on Monday, written from projects where it had to.
- 018 steps
Running an Office Floor Restack
Everyone sits down Monday and their machine works.
A restack is a logistics problem wearing an IT costume. The technical work — unplug, move, plug in — is the easy part; what decides whether the floor opens is the seating map, the labelling scheme, the freight booking, and knowing which twelve people cannot be down for an hour. This is the sequence we run, written from phased moves of four to two hundred users.
Who reaches for itAnyone with a floor date, a seating plan that changed twice, and a building that only allows freight before 7am.
Open - 027 steps
Asset Tagging and CMDB Audits
The scan is easy. Scanning it into the right record is the job.
What a field technician actually owes an asset database, and why most of what goes wrong is not the tagging. Covers the difference between an asset record and a configuration item — the distinction ServiceNow builds on and the one most site work gets wrong — what to capture at the desk, how to run a floor audit that produces a usable reconciliation, and what to do about the machines that are on the floor and in no system at all.
Who reaches for itAnyone tagging hardware for a client who runs ServiceNow or a similar CMDB, and anyone asked to audit a floor and report what is actually on it.
Open - 037 steps
Parcel Locker Site Surveys
Whether the unit fits, powers, connects — and gets in the door.
The survey that decides whether a parcel locker can be installed at a site, written from several dozen of them across the five boroughs and North Jersey. Covers the measurements that actually stop an install, the power and signal questions, floor loading, and the access constraint that is invisible on a floor plan: the route from the truck to the final position.
Who reaches for itField technicians sent to survey a candidate site, and hosts working out whether their lobby or back room can actually take a unit.
Open
Reference
The words,
and what they mean
Definitions written for someone standing in front of the thing, not someone reading about it. Searchable and cross-linked.
How these are written
Every one of these is something we have had to explain on site, usually to somebody competent who had simply never been shown.
There is a lot of wiring information on the internet and a great deal of it is wrong, contradictory, or a nine-minute video of somebody’s hands. So these say the thing plainly, show the colours rather than naming them, and are specific about where the standard ends and field practice begins — because those are not the same, and pretending otherwise is how people end up defending a decision they cannot source.
House rules
No account, no email gate, no video.
Nothing you enter is stored or transmitted.
Colour is never the only way information is carried — every swatch is named in text.
Where a standard specifies a number, it is cited as a standard. Where it is field practice, it says so.
Guides, not engineering sign-off. On a job with a certification requirement, certify it.
Book the work
We pull the cable as well as explain it
If you are reading a termination guide because a building full of it needs doing, that is the work we do. Estimates are free and the conversation costs nothing.
- Free guides
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- Nothing tracked
- Written on the job