Can Anyone Recommend a Telephone Systems primer?

Yeah, I’ve been scouring for a while looking for a primer to inform me about telephone systems, but I’ve yet to find anything to my liking. I’ve been looking for something along the lines of this book, but something perhaps a little more technical and up-to-date. I actually thought that the above book would do, but the comments changed my mind.

Thanks fellow geeks,

Now to watch the thread views roll in :rolleyes: