Mike Tooley & Steve Winder 
Newnes Data Communications Pocket Book [PDF ebook] 

Despite the complexity of the subject, this wealth of information is presented succinctly and in such a way, using tables, diagrams and brief explanatory text, as to allow the user to locate information quickly and easily. Thus the book should be invaluable to those involved with the installation, commissioning and maintenance of data communications equipment, as well as the end user. — A practical engineer’s reference that puts the key information at your fingertips- Covers essential data, techniques and working practice- This update covers the latest international regulations