I'm going to try out openwrt - so I'm a newbie!

I currently have a regular broadband connection in the UK and I use the Service Providers free modem/router.

I'm looking to acquire a modem to use with openwrt and there is quite a few makes, model and hence specs to choose from. I don't understand the ADSL, VDSL, ADSL2, ADSL2+ and VDSL2 "options" that various modem/routers offer.

What's the difference between these technologies?

Which is the best to have?

Which one(s) would tech you insist upon having in a modem/router if it made a difference?

Thanks for your advice.

You need a modem matching your ISPs capabilities at your location; the good part is that most modems are backwards compatible (and you almost sorted the options in correct ascending order, for the details of technical capabilities and expectable throughput wikipedia has a lot to tell).

Just in short, if all your ISP can offer you at your location would be one of the ADSL flavours, paying retail price for a VDSL2/vectoring modem (at retail prices a factor of 2-4) wouldn't really be worth it (on the other hand, even those can be bought for a fiver in the used market, so...). With technologies still changing (e.g. super-vectoring far at the horizon), it doesn't make lots of sense to overspend just in case (unless you're certain that $new_technology will become available to you within the next 6-9 months).

And yes, it does make a lot of sense to put the demarcation line between internet (ISP network) and your private LAN on your own hardware (own software), without resorting to kludges like double NAT.

(Last edited by slh on 1 Feb 2018, 00:06)

ok thanks,

how can I tell which ADSL tech my current modem is using?

You take your current modem(-router) out for dinner, maybe a good bottle of red wine, and when it gives you its model number, you look up its datasheet on the internet.

Or you look at the box it came in.

Or you look into the contract you have with your provider.

Or you look into your current router's web interface, it may tell you which type of line you are connected to.

Or you can make an elaborated guess, if your line speed is less than 20 MBit/s, it is almost certainly ADSL.

There's really only two things to care about:

a) The annex. You will use "Annex A", since you are in the UK.
b) And it will either say "something-including-a-V"-DSL or "something-not-including-a-V"-DSL

For all intents and purposes, there is only VDSL and ADSL, and only when you have VDSL we need to care about more elaborate capabilities like "vectoring".

(Last edited by metai on 1 Feb 2018, 21:57)

"in the UK" I would guess that you should be happy with a BT homehub5a which is supported decently by lede* and should work with both ADSL and VDSL in the UK. Since AFAIK BT/Openreach are not quantitatively using vectoring you will not even need to try to get hold of a vectoring capable firmware.

*) decently after you did the soldering to actually get a lede firmware installed in the first place, but then again there might be already flashed to lede devices on ebay...

Yes if you have your modem's login credentials, log in and check the signal status page.

Generally if you over-buy your modem will be able to fall back to a slower service / older standard if that is what is on the line.   

VDSL is seldom installed in rural areas since though it newer and much faster than ADSL, it can only work through a few hundred meters of wire pair back to a phone company device.  ADSL can go for kilometers.  VDSL is very practical for apartment buildings.

Thanks for that but we have no decent restaurants nearby.
I threw away the box - I'm about to do the same to the router!
I don't know what speed they should be giving me - 45Mb/s? Or thereabouts?

The router is locked down so it won't tell me on one of the config pages what it's using - even the up/down speeds are hidden - what a crap router - I must replace this - Hey That's why I'm here! Select an appropriate openwrt compatible router and go go go!

Anyway, I just picked this from sifting through the router's event log:

PPPoE is up - Down Rate=39950Kbps, Up Rate=9999Kbps; SNR Margin Down=13.5dB, Up=22.7dB
WAN operating mode is VDSL

So VDSL? - I didn't think the UK had VDSL?

The UK has VDSL, although it's often called FTTC (fibre to the curb, but VDSL/ VDSL2 over copper from the curb (or rather the SAI cabinet) into the house).

The VDSL2 capable BT Home Hub 5 Type A should be a decent choice for that, but be aware to read its wiki entry before buying one. Given this thread, I doubt you'd be comfortable with doing the initial flashing yourself and would recommend looking for one preflashed with LEDE instead (as using that avoids soldering and can be sysupgraded as needed).

I am comfortable with flashing and programming stuff I just need the manual and decent info as a guide.

Here I just didn't know the difference between ADSL, VDSL, ADSL2 etc. and what my connection is here and therefore which modem I would need to get the best from my connection.

With FTTP being available I may not need to worry about this for much longer.

Thanks for all your assistance.