You are absolutely right. The book and spec is wayyyyy too outdated and the book is utter sh¡t. Example "benefits of ISDN" answer "fast connection, wide bandwidth". Are they raking the p? 128kbps is not fast or enough bandwidth try loading (not watching) YouTube XD
Some questions are repeated with slight wording changes but the marks and answers are nearly completely different.
Oh BTW edexcell your paper should be called designing from the past to the present.
Good luck to us.