High latency for a gamer, and a strange noise in the MDF room

The job

We were called to a unit in Rosehill on fibre to the building. The customer played competitively and was getting lag, stutter and rubber-banding in games. Measured, it was latency spiking as high as 200 milliseconds, with packets going missing in bursts.

Web pages loaded. Video streamed. That is typical of this kind of fault: browsing and streaming hide a small amount of loss and delay, and a game or a voice call cannot.

Watch: Strange Jitter Noise Coming From MDF Frame Is Affecting Pro Gamers Internet Quality NBN FTTB

Latency, jitter and packet loss, in plain words

• Latency is the delay between sending something and getting the reply, in milliseconds.
• Jitter is how much that delay varies from one moment to the next.
• Packet loss is data that never arrives and has to be sent again, or is simply missed.

A speed test measures none of these well. It says how much the line can carry, not how evenly, which is why our speed test page is the place to check speed and not lag.

Where was the test run?

Tested in the unit Tested at the building frame

Slower reply Time 1Latency: one slow reply 2Jitter: replies arriving unevenly 3Packet loss: replies that never came Steadier, the same window at the frame

1. Latency: one slow reply
2. Jitter: replies arriving unevenly
3. Packet loss: replies that never came

In the unit, the reply times jumped about: slow spikes, uneven runs, and bursts of replies that never arrived. Web pages and video carried on as if nothing was wrong.

At the building’s frame, the same test ran steadier. That showed the disturbance was being picked up between the frame and the unit. It did not, on its own, show what was causing it.

What we tested

We tested it the way we track down any fault that comes and goes: at the unit, then back at the frame, and compared the two.

1. 1

   In the unit

   Ping tests from the customer's unit showed the spikes and the loss clearly, worst on the kind of traffic games use.

2. 2

   The unit's cabling

   We measured resistance and continuity on the cabling from the unit, and to earth. Every reading was within normal limits. Nothing was wrong with the cable as a cable.

3. 3

   At the frame

   We went to the building's main distribution frame in the basement, where NBN's service is handed to the building's wiring, and ran the same ping tests there using the provider's test router connected at the jumper.

4. 4

   Comparing the two

   The results at the frame were better than the results in the unit. Whatever was disturbing the service was being picked up between the frame and the unit.

Testing from both ends of a line, and writing down what each end shows, is the core of what an independent NBN technician does on site.

The noise in the frame room

While testing in the frame room we noticed a jittering noise that could be picked up on the steel: the frames, the cable trays, even the fibre frame. It was on one piece of metalwork after another.

Then we checked the earthing. None of the steel frames was earthed. The fibre termination point appeared to have an earth, but it made no difference to the noise on everything else.

Unearthed metalwork in a room full of cabling gives electrical noise somewhere to sit, right beside the copper pairs that carry every unit’s service. That fits what the tests showed: a line that carries plenty of data and still corrupts a small share of it.

What we recommended

1. Earth the frames. Every metal frame and cable tray in a frame room should be bonded to earth. It is a standard requirement for this kind of installation, and here it was missing.
2. Further testing by the provider. We asked for the provider to arrange a second-level NBN technician to test the path from the frame to the unit.
3. Look for the source of the noise. Earthing gives noise a path away. Finding what is producing it, such as plant or equipment elsewhere in the building, is the other half.

If your unit has the same lag and nobody has found why, an internet technician can test from your socket back to the building’s frame.

Whose job is it?

Not the tenant’s. The frame room, the frames and the cabling between the frame and each unit are the building’s, the same frames every unit’s jumper is run on. Earthing them is a matter for the owners corporation or the building manager, and the work is for a licensed electrician.

That is the hard part of a fault like this for a renter. The symptom is in one unit, the cause is in a shared room, and the person suffering it has no authority over that room. What we could give the customer was a written finding to put in front of the provider and the building manager, saying what was measured and where.

For how a building’s wiring is put together, see what fibre to the building is and what MDF jumpering is. If your connection drops out rather than lags, see why an internet connection is unstable. Another unit block job, where the line was dead rather than noisy: no internet in a new apartment, and three faults on one line.