If your exchange is unbundled by Orange you will be put on LLU, if not you will be put on IP/datastream, cant remeber which one Orange use in non llu'd exchanges.
Best way to find out is to go to samknows.com and enter your details to view who has un-unbundled your exchange.
Remeber you will also need a MAC code from Plusnet to go over to orange, if not you will have to cnacel Plusnet and then wait until BT have done all the ceases before you can place a new ortder with orange and be forced to pay the connection fee.
Originally on <n>ildram Broadband Pro (2mb)
Work ADSL - Now resold from Entranet
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