 Access' means. Most likely no one type of access technology or media will clearly prevail, and many different types of access will be selected and coexist, at least in the short run. Hybrid systems will also appear, such as UMTS-WAN. Telecom management will have to manage a large number of different networks assuring seamless integration among all of them. They might be different access networks, existing legacy networks and the stratified core network. The proper and easy integration of the O&M activities on access, within the operator's telecom management, will then become a key element for assuring both business and operational success. 16.12 MANAGEMENT OF LAYERED AND SERIAL INTERWORKING The complexity of modern networks, handling many different technologies simultaneously with a considerable number of layers and a fast pace of technology development, creates Telecom Management - Operations Telecom management Agnostic access Cellular networks GSM and 3G etc IP Backbone PSTN GW VoDSLGw Gigabit ethernet Voice Data/MM DSLAM Ethernet modem Figure 16.24 Access network management overview difficulties in acquiring a proper telecom management understanding and management competence. The two considered cases are: single operator with many layers or many interconnected technologies, and interworking operators in layers or interconnected. The interfaces and protocols are far more complex in interworking than in integration. The interworking protocols have to support the distribution along all planes (traffic plane and management plane) and layers (OSI-ISO layers) of the interconnected networks. In other words, they have to assure that the interconnection is held along all the layers com- posing the different networks, and that both traffic and management plane interconnection are included. The complexity is even greater when the two interconnected networks do not provide exactly the same services (mobile and fixed telephony, LAN and WAN, X25 and IP, PSTN and VoIP). In this case the gateways have to be able to handle th