Mobility Field Day - NetAlly's LANBERT

So James opens with a doozy… (this is me paraphrasing… don’t quote me quoting him…)

“So you know that speed your cable is rated for? yeah, it can do a lot more than that…”

So it turns out that the speed you’re told about for a cable is the minimum, not the limit… Now, I’ve always known that in some way but when you think about it, it really makes sense.

I’ve been a part of loads of projects where clients have completely re-cabled entire buildings to make sure they have the latest and greatest so that their switches and access points are ‘future proof’. In some instances I’ve gone along with it; after all, the need for multi-gig links to APs has been just around the corner for years now 😉.

What I didn’t often stop to question was whether or not the cables that were already there (in most cases Cat5e) would do the job…

Modern Digital Signal Processing

This is because most cable testers are running tests not based on speeds, but off of the standards. So they’re saying that this is the minimum anything can run on this cable. James used an analogy of a Lorry (UK speak) taking a turn compared to a sports car. The cable says the speed limit is 1 Gbps because it’s safe for the lorry to take the corner at that speed. That doesn’t mean that a sports car couldn't take it quicker (say 5Gbps). He didn’t like the analogy in the video but it helped me! Especially when you consider that most modern Digital Signal Processing is effectively the ‘sports car’ we’re all driving today.

SNR controls speed for Wired and Wi-Fi

Using a NetAlly Etherscope nXG or a LinkSprinter 10G (you need two devices to run the test but it could be a mixture). You can run the LANBERT test which actually sends data and tests to see what it’s capable of doing. It works much the same way as Wi-Fi modulation does… if it can’t reach 10 Gbps it downshifts and does 5 Gbps; then 2.5 Gbps and so on. so you might not be able to get 10Gbps out of your old cat5e cable… but it’s very likely you’ll be able to get 2.5 Gbps which is the most you’ll ever need for an AP (I’m aware you probably won’t even need that just yet but…)

Not Certified but running 10 Gbps!

So you might not be able to ‘certify’ that something will do 10/5/2.5 Gbps but it may well be able to do it!

I don’t know why I’m trying to explain it… James does an awesome job in the presentation.

Cable fails 1Gbps Certification but can actually pass 5 Gbps!

Anyway, here’s the video, It’s well worth a watch! Oh and apparently your office chair is killing your network… ⚡️

Can’t wait to get my hands on another nXG or a LinkSprinter 10G so I can give this a go… as soon as I do I’ll do another post here to go through some hand’s on testing.