It is the first English publication of a book, originally published in Russian, that has been widely recognized in Russia and went through three editions.The book covers one of the key technology problems existing in Russian, CIS and East-European telephone networks — the interoffice signaling, and includes a short description of some important technical aspects of the Russian PSTN. Since drastic and, in some way, dramatic changes have taken place in that PSTN, the book reflects developments in this rapidly evolving area. The author gives a clear, detailed account of current telephone network technology, and analyzes the standards and interoffice signaling protocols. He describes how the technology has evolved from direct current signaling to common channel signaling system No.7, and demonstrates the techniques and methods required for evaluation of signaling systems to ensure their functionality as well as quality of their design. After giving an introductory material concerning Specification and Description Language, SDL, the book focuses on protocol specification techniques for various signaling systems.When preparing this English edition of the book, its text has been thoroughly revised and updated to include new data. So, the book provides a reader with original information, and with that carefully selected from papers, handbooks, monographs, recommendations, standards, reports and other materials of East Europe telephone industry. Being concentrated both on general signaling protocol principles and peculiar East Europe PSTN protocols, the book:Examines the way in which the former USSR signaling protocols developed.Draws together and discusses the whole range of technical solutions, from three-wire analog signaling system to common channel signaling No.7 protocol.Gives practical guidance, often through case studies, on the ways in which the critical interworking problems can be successfully solved.