Steam repeatedly disconnecting

[#1]

I play Football Manager 13 online with a friend. But every 10 minutes my connection is dropping... but only with Steam (the client in which FM13 must be played). It usually disconnects once or twice a night, tonight it's every ten minutes making it unplayable but it's only me. None of my friends are disconnecting on Steam. I've troubleshooted Steam and nothing is going on there. Here's some pictures from my router if it can help;
http://www.fm-base.co.uk/forum/faq.php?faq=net_games
https://support.steampowered.com/kb_article.php?ref=8571-GLVN-8711
This is different from what is on that article, but this was preprogrammed. Maybe Plusnet need to update their ports?

[#2]

Hi there,
You seem to have everything set appropriately on your router config as far as I can see and all the right ports for the game and steam clients are specified.
At this stage it would be worth trying another router if you're able to get your hands on another just to rule out an issue with that.
Also if you can running a wireshark capture whilst this is happening may capture some revealing information for us: http://www.wireshark.org/

[#3]

It's still happening and this time it was when I loaded up FIFA. Much like FM, I enter the game fine then after a short time it disconnects. Steam had also disconnected (but my internet in general was still working). If my internet did go down then it wasn't doing for more than 20 seconds or so. I also noticed earlier that my VPN wasn't booting up which I'm guessing is related to this too.
I unfortunately don't have another router I could try it out with. I have a Sky router but it doesn't let me enter my Plusnet username and password (as I've tried this in the past).
I'll try the wireshark capture thing now. This is it live;
My Broadband Ping

dick:quote

[#4]

Not much has changed and I need to go to work now. I'll post later if what it's already gathered isn't enough and I'll try playing games and things later too.

[#5]

Just noticed you changed the link in your post. I've downloaded and installed Wireshark with WinPcap and it's now running. What am I looking out for now it's capturing from the LAN?

[#6]

To begin with you'd be looking to see if the traffic is classified correctly but I suspect it is.
How exactly have you configured the router? Is the machine you're playing from in the DMZ? If it is then all of the port forwarding, UPnP, game mode stuff etc. is irrelevant really. I'd expect you to be using one or the other. As long as UPnP is enabled I'd kind of expect things to just work anyway if I'm honest.
The connection at this end looks stable but the latency displayed by your TBB monitor doesn't look great. What else are you doing when you're trying to game?