Hi all,

We need a bit of help with some testing over the next few weeks. As many people will probably know there's a finite number of IP addresses in the world and there aren't many left. In order to ensure that people have access to the Internet during the transition to the new world of IPv6 ISPs like ourselves are looking at options including Carrier Grade NAT. Even if the world switched on IPv6 today there would still be people and applications that don't work under IPv6, some games consoles for example. As such everyone will still need an IPv4 address for the foreseeable future.

Carrier Grade NAT (CGNAT) is similar to the NAT that people use on their home routers. The NAT on your home router lets all the devices on your network (PCs, tablets, phones, consoles etc.) share one IP address. What CGNAT does is take that a step further and has several customers sharing one IP address. For most people they will never notice, most mobile operators already use CGNAT and so most applications will just work. The main problem is where you are hosting services on your broadband connection like hosting a website or hosting games (the kind of thing for which you set up port forwarding on your router).

We're just about to test and evaluate a CGNAT system to see if it's suitable and see what kind of applications and services work and don't work, as such we'd like a bit of help from people to try out and see. We're doing testing internally too but with so many devices, applications, games, VPNs, etc. we'll never test everything. With some help we'll try and get as much as we can.

What we want from the testers is just to do what you would normally do, we'll give you a special username to use so that if you do find things that you need to work but which don't you can easily switch back. We'd also like you to record what works and doesn't on a spreadsheet (we'll probably use Google docs just to make it easy).

If you can help then please reply, the trial is due to start in a couple of weeks and is expected to last around 3 weeks.

Any questions then please let us know.

I'm happy to test this on my second line Matt.

Does this mean that anyone who wants to use port forwarding wouldn't be able to?

How does "IPV4 sharing" work with protocols such as https e.g. online banking applications?

Well, technically they could forward the ports on their router, but as you can't forward the port on the external IP of the CG NAT that would mean that no traffic would actually be able to be delivered to them.

Pretty much the same way it does at the moment. Return traffic (i.e. replies to an application that's from from a specific internal NATted IP) is fine, that can be replied to. The issue is with incoming traffic - the CG NAT interface wouldn't know which of the customers sharing the IP it's aimed at to route the traffic to.

No trial for me then - it clearly can't support the TOR network. 
Also sounds a bit dodgy for P2P applications, although it has the advantage that knowledge of a received IP4 address no longer tells you anything about the identity of the sender.

Sorry, but that lets me out too I'm afraid, need port forwarding for reverse VNC to provide online support to relatives. Otherwise it would have been interesting to see how VPN and VOIP was handled.

We'll set up a separate username for the trial so if there are things that don't work you can easily switch between the two accounts if that helps.

I am willing to take part in the trial.

PeteB

Happy to assist Tommo

M

MisterW:  You are actually the sort of person we want to elp us. h You'll just change your login details over, and let us know what doesn't work.  If you need those apps, you can swap back

Ok Kelly I'm happy to help, there is a possible slight problem but I'll drop you a PM.

Hi all,

Thank you very much indeed - we'll be in touch in the near future with a bit more detail for you.

@MisterW - thanks very much, Kelly's had a word and that won't be a problem at all - just change the username and password back to that of your own account whenever you need to, and the more information we get from this trial the better

I'll help out. Am I correct in assuming that devices on the same external IP won't be able to talk to each other behind the NAT device?

Alex

I'll help out too.

David

Hi,

I'd like to help out with this.
99% of data through my Plusnet line is via an encrypted L2TP stream, I doubt this will be affected but it'd be interesting to see. (I run an L2TP tunnel over each DSL line to an LNS endpoint that "bonds" multiple lines together).
I'm more interested in finding out how well stuff like Teamviewer, Bittorrent and VoIP works natively over a CGNATted connection though.

Count me in on the trial!

Olorin

I use a fair bit of stuff, so yeah count me in if theres spaces left.

Cheers, Meh!