bility anchor between 2G/3G and LTE SAE anchor: Mobility anchor between 3GPP and non 3GPP Communication Networks LTE access network Figure 9.9 LTE simplified architecture. 3GPP anchor SAE anchor 3GPP access Non-3GPP access Figure 9.10 SAE simplified architecture. While the initiatives for next generation networks development are specialized domains, by separating the access and core network the standards for network man- agement of next generation networks are also handled by specialized forums like TMF where generic standards for managing a variety of networks are developed. 9.11 Conclusion This chapter gives an overview on some of the most popular telecom networks. It can be seen that networks mainly have an access and a core component. Most network management solutions are developed for handling either access or core network. Technology is moving toward a converged network for enterprise and telecom with an All-IP infrastructure as the backbone. Network management solutions and standards are also moving in the direction of managing converged next generation networks. Fundamentals of EMS, NMS and OSS/BSS Additional Reading 1. Ronald Harding Davis. ATM for Public Networks. New York: McGraw-Hill, 1999. 2. Timo Halonen, Javier Romero, and Juan Melero. GSM, GPRS and EDGE Performance: Evolution Towards 3G/UMTS. 2nd ed. New York: John Wiley & Sons, 2003. 3. Miikka Poikselka, Aki Niemi, Hisham Khartabil, and Georg Mayer. The IMS: IP Multimedia Concepts and Services. 2nd ed. New York: John Wiley & Sons, 2006. Luc De Ghein. MPLS Fundamentals. 2006TMF 513, Multi-Technology Network Management Business Agreement. Indianapolis, IN: Cisco Press, 2006. Chapter 10 Seven-Layer Communication Model This chapter is intended to provide the reader with an understanding of the ISO/ OSI communication model. Any communication between two elements or devices is possible only when they are able to understand each other. The set of rules of interaction is called a protocol and the tasks in the interaction can be grouped under seven layers