Unexplained Usenet usage

[#1]

Have you checked your router for unknown devices connected to it?
What's your normal Internet usage like (in terms of what do you do on the Internet - any progs like DropBox etc.)?

[#2]

I've never seen any unknown entries in the list of devices on my router - and since a couple of weeks ago, access has been MAC-filtered and the password changed.
I do use Dropbox for the odd document, nothing close to the amount that's being logged as Usenet. My normal usage is mainly web browsing (news, forums, social networking, buying online), a few streaming videos, some Skype.
As I was saying upthread, I wonder if Skype could have something to do with it? It's the only app I can think of that could be generating that volume of traffic - but then again, why would Plusnet categorise it as Usenet? 

[#3]

Common Usenet ports = 119, 443, 563
From Skype support:

Quote

To work correctly, Skype requires unrestricted outgoing TCP access to: All destination ports above 1024 (recommended) or Ports 80 and 443 https://support.skype.com/en/faq/FA148/which-ports-need-to-be-open-to-use-skype-for-windows-desktop

So both Skype and Usenet can use port 443. Looks like that explain things.  

[#4]

I think you're on to something, but...
In my installation of Skype, the checkbox that says "use port 80 and 443 as alternatives for incoming connections" is not ticked! It's set up to use a much higher port number.

[#5]

No, it's outgoing connections which are important here.
Try blocking outgoing port 443 in the routers firewall and see if that stops this reporting of usenet traffic.
I'm guessing Skype will use a alternative port if 443 is blocked.

[#6]

Ah OK, I think you've got it - thanks! 

[#7]

Yep, Skype would match my 'Usenet' quantity and the fact that there is no overnight usage.  But if Plusnet cannot correctly identify Skype traffic, does that mean they do not prioritize it correctly?

[#8]

I would imagine the website usage breakdown is a less sophisticated, port based categoriser for user traffic.
You could try using Skype (over port 443) and running Wireshark to make sure the packets are being captured and treated properly by PN's traffic management system. I believe it should have the value 0xa0 (Titanium) in the Differentiated Servcies Field.

[#9]

If you block outbound access to tcp port 443 then you won't be able to access https websites.

[#10]

Good point  
On this basis secure web pages are presumably classed as usenet. 

[#11]

On day one of my billing month we made a one hour Skype call.  The result is that my total usage is shown as 45% Usenet although I don't use Usenet.  0% 'Broadband phone calls' usage, by the way.  So Skype (with default settings) is undoubtedly (mis-)identified as Usenet by Plusnet's View my Usage monitor.