Field guide · Testing & verification
Certifier reports
A certification report is a compliance document, not a pass sticker. 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.
Plate 01Questions
Questions people actually ask
- What is the difference between a tester, a qualifier, and a certifier?
- A tester checks continuity and wire map — it tells you the eight conductors reach the right pins. A qualifier adds a judgement about whether a given speed will run. Only a certifier measures the frequency-domain parameters against a TIA or ISO limit line and produces a report that satisfies a manufacturer warranty. If somebody asked for certification, the first two do not answer the question.
- What does a PASS with an asterisk mean?
- The result is within the accuracy tolerance of the instrument at that measurement, so the tester cannot say with confidence that it passed — it is marginal. It is a legitimate result to record but not one to hand over silently. Treat it as a re-termination candidate, because a marginal link is the one that fails when the room warms up.
- NEXT failed. Is the cable bad?
- Almost never. Near-end crosstalk failures are overwhelmingly a termination problem, and the specific cause is untwist — pairs opened up further than they should be at the jack or panel. Re-terminate both ends keeping the untwist under half an inch before you consider pulling the run.
- Insertion loss failed. What now?
- This one usually is the cable or the length. Check the measured length against the limit first — a run over 90 metres of horizontal cable will not pass regardless of workmanship. If length is fine, look at whether the run is copper-clad aluminium rather than solid copper, and whether it has been through heat.
- What is delay skew and why does it matter?
- Different pairs in the same jacket can have slightly different physical lengths and propagation speeds, so bits sent together arrive apart. Gigabit and above use all four pairs simultaneously and reassemble them, so too much skew breaks the link. Large skew usually means the pairs are made of different materials, which points at cheap cable.
- Do I test the permanent link or the channel?
- Permanent link for a new installation you are warranting — outlet to patch panel, excluding patch cords, because that is the part you installed and the part that stays. Channel when you are diagnosing what a device actually experiences, cords included. Reporting one when the specification asked for the other is the most common reason results get rejected.
Plate —Other guides
The rest of the section
- 01RJ45 Wiring: T568A and T568BBoth colour codes, pin by pin, side by side.
- 02RJ11 Wiring and Phone PinoutsSix positions, three lines, two colour systems.
- 03Keystone Jack TerminationStrip, seat, punch, snap — without failing the certification.
- 0466 Block WiringFifty rows, four columns, and where the bridging clips go.
- 05110 Block WiringLay the pairs in, press the connecting block on.
- 06Cat5e vs Cat6 vs Cat6a vs Cat8Speed, distance, and power decide it — not the bigger number.
- 07Fibre Types, Connectors and PolishRead the jacket, read the connector, don't mate blue to green.
- 08Subnetting, ExplainedWhere the numbers come from, and the meaning behind them.
- 09PoE Standards and Why It Won't PowerThe switch reserves the class, not the draw.
- 10Camera Lens, Field of View and Pixel DensityCovering the room is not the same as identifying a face in it.
- 11Patch Panels and Labelling to TIA-606A label that survives is worth more than a tidy rack.
- 12Rack Planning: Units, Depth, Weight and HeatIt fits vertically. That was never the hard part.
- 13Writing a Switch ConfigurationFrom factory default to a switch you would hand over.
- 14Networking and Cabling GlossaryThe terms, and what they mean on a job.
- 15POTS to VoIP: What BreaksThe lines nobody remembers until they stop working.
- 16Testing an Analogue Phone LineTip, ring, and the four numbers that tell you whose fault it is.
- 17Toning and Tracing a CableFinding one pair in a bundle of two hundred.
- 18Which Cable Tester Do You Need?Three tiers, and the one most people actually need.
- 19Running an Office Floor RestackEveryone sits down Monday and their machine works.
- 20Cable Management for Desks and RacksTidy is a by-product. Serviceable is the point.
- 21Asset Tagging and CMDB AuditsThe scan is easy. Scanning it into the right record is the job.
- 22Cabling an Office Fit-OutHow many drops, run where, and what it takes to add one later.
- 23Parcel Locker Site SurveysWhether the unit fits, powers, connects — and gets in the door.
- 24VLANs and TrunkingAccess, trunk, tagged, native — and which one is the security hole.
- 25Spanning Tree and Switching LoopsWhy one patch cord can take a whole floor down in seconds.
- 26Reading a TracerouteWhich loss is real, and whose network it is in.
- 27DHCP, DNS and Helper AddressesWhy the new VLAN gets no addresses, and why it is always DNS.
- 28Wi-Fi Channel Planning and AP PlacementMore access points at lower power, not fewer at maximum.
- 29SMART Attributes That Predict FailureA drive can report PASSED while it is visibly dying.
- 30BitLocker: Keys, Recovery and EscrowThe key exists somewhere, or the data does not.
- 31Grounding and Bonding a Telecom RoomOne ground, one path, and no loops between rooms.
- 32UPS Sizing: VA, Watts and RuntimeThe number on the box is not the number you need.
- 33Mounting Displays on Any WallFind the structure. Everything else is a repair bill.
- 34Mounting IP CamerasHeight, angle, and the surfaces that ruin the picture at night.
Free guidesNo sign-upNothing trackedWritten on the job
Rather it was just doneWe do this work
We do this work
as well as document it
Anyone handed a set of results to sign off, or holding a failure and trying to work out whether to re-terminate or re-pull.