Hi Poe thanks for the quick response!

That's really good to know. I've actually already done the test directly to the router and was indeed getting huge packet loss as you can see here:

https://share.pingplotter.com/8xgpSBMcjZn

Weirdly though you will notice there was little to no packet loss between 1700 and 1830.

I have just ran the trace to my interface on the loopback address for 30 mins and all squeaky green with 0 PL.

Going into a little more detail on my original post.. as the ISP has already replaced the router (for a later/ 'better' model too) I imagine it's extremely unlikely that the router itself is at fault right? I am now starting to think something environmental such as EMI. The router is on a middle shelf under the till station - Directly behind it (within 6 inches) is a power strip with 3 or 4 DC power supplies connected to it for the various equipment that is on the shelves above and below (NVR for wired CCTV, NVR for wireless CCTV, audio amplifier, etc!) I actually think we have 5 6-gang power strips daisychained from one single wall socket Also I can't be certain whether the ethernet cables I have used to hook my laptop up to the router are shielded.

So do you think we can be confident the packet loss issue is on the LAN side of the router? Meaning it's not worth replacing the ADSL cable at this point? (appreciate this would usually be quick and easy to do in a normal domestic environment, but the cable for our setup runs in some trunking under the floor back to the ADSL socket)

I guess maybe the next step would be to move the router to an interference-free location and plug the power directly into an outlet on the wall?


Really interested to find out what the cause of this PL is.. but even more so I hope it also turn out to be triggering the issues we're getting with our order system app!

Cheers

AG

Ps. I'm unable to see anything from your links (it goes to a page showing 'Access Denied')