How to fault find a bandwidth issue?

Hi all, I’m a Jack of all trades master of none edu ICT systems guy, I have HP/Aruba gear generally speaking.

What I have a problem with is that I have 10gb fibre from the core to edge switches that are then gig to client. In a bunch of the edge switches the clients get as close to 1gb up and down as I could want, however, in a bunch of locations I get between 500-300mb.

For the general clients that’s really not a big deal, but my AP’s plug in to those switches and then the problem obviously becomes bigger as instead of 1 client for each ~300mb I could have one AP with 30 users on it and then they only get that same bandwidth between them.

They are all the same config, the switches. They all go 10gb fibre to the core. There is no obvious damage to cables, I’ve tried going from a fly lead to a laptop straight into the switches to cut out patch or room cabling issues, but with no joy.

I’m not a mega network geek, I can and do get by in the cli doing some vlan stuff and some diagnostics on issues now and then, but I don’t know how to trouble shoot this issue - is there some way I can do something on the switch to see where the slowness comes in?

Any thoughts would be most appreciated.

Also, im ok on the edge switches cli (procurve/Aruba) but the core is Comware and the cli on there scares me! Dunno if that will matter to any options I might have.

Do fibre cables degrade? I just can’t understand it.

Thanks