OK Carphone Wharehouse has & always has been TalkTalk, it now owns AOL (which remains a independently run company IIRC), they also own Tiscali, which means they own Pipex plus numerous others....Tisacli is/has been assimulated into TalkTalk & now is TT..no more Tiscali...probably an image thing.
Now Nick has posted a fairly good description of LLU etc. what isn`t pointed out is that many will have taken TT`s lovely cheap all in one package & now on TT`s network which means if you wish to switch you`ll have to then rejoin BT which if memory serves will cost £125 (yep same as a new line), then you`ll get a charge for re-enabling ADSL with an ISP (some ISP`s will absorb the cost, but lumber you with a 12-24mth contract).
I `m with Be like Nick, but it allows me pick & choose ISPs, either via BTW or via LLU & I retain BT for my phones. Cost wise its likely more than a fully unbundled package, but its gives us choice & freedom.
I know much of this is techie, so this might help.
LLU = Local Loop Unbundling (ie: the ISP has their kit/hardware in your exchange).
BTW = Brtitish Telcom Wholesale.
BT = British Telecom.
OR = Open Reach.
ADSL = in simple terms Broadband
BTW, BT & OR are all effectively BT, but have to run themselves independently or is it offer the same services to ALL companies irrespective. Some say there is a conflict, I don`t know.
BTW resell the network connections to any ISP that wishes to use it, price must be the same to ALL ISP`s including BT.
BT is the retail side & talks to Us the mere people who use their phone service or perhaps their ADSL services.
OR is the company that fixes the faults on the network, now I`m a little unsure if they do both phone or only ADSL, I believe its only ADSL faults.
Yes it gets complicated & confusing.
Just to add a bit more confusion...in the case of ALL LLU ISPs the copper cable from the exchange is owned/maintained & therefore fixed by BT/OR.
There are another couple of bits to confuse people more, Virgin "Cable" which IIRC was Telewest & a few other names, now collectively Virgin Media use a completely separate system from BT.
Another bit is in Hull which is Kingston Communications they effectively have a monopoly on supplies of both Phone & ADSL.
I`m sure some will now be totally confused....sorry...just trying to explain.
Steve