Computer networks and telecommunication is one of the fields of computer management, which the whole world is delighted about. As for the technicians in the profession, learners, researchers and others are experiencing enormous difficulties as a result of the lack of books in the field or in our libraries, as virtual books are not accessible everywhere.Putting such a book in the field is a way of overcoming these difficulties, so that every user can at least contribute to/benefit from it. Computer and telecommunication networks, which are shaking up all businesses in terms of their performance and trade, are helping and satisfying employers in the day-to-day running of their businesses, which has been difficult in previous years. People have to travel long distances, with all the possible risks, to obtain a document, to check a message, to follow a training course, to repair or buy an important tool, etc.