Optical Networks: A Practical Perspective - Part 54. This book describes a revolution within a revolution, the opening up of the capacity of the now-familiar optical fiber to carry more messages, handle a wider variety of transmission types, and provide improved reliabilities and ease of use. In many places where fiber has been installed simply as a better form of copper, even the gigabit capacities that result have not proved adequate to keep up with the demand. The inborn human voracity for more and more bandwidth, plus the growing realization that there are other flexibilities to be had by imaginative use of the fiber, have led people. | 500 Control and Management as transponders amplifiers multiplexers and so on. With respect to this there may be an object class called rack which has as one of its attributes another object class called shelf. Multiple types of shelves may be represented in the form of inherited object classes from the parent object shelf. For example there may be a common equipment shelf and a transponder shelf which are inherited from the generic shelf object. A shelf object has as one of its attributes another object called slot. Each line card object is associated with a slot. Multiple types of line cards may be represented in the form of inherited object classes from the parent object line card. For example the transponder shelf may house multiple transponder types say one to handle SONET signals and another to handle Gigabit Ethernet signals . The common equipment shelf may house multiple types of cards such as amplifier cards processor cards and power supply cards. Each object has a variety of attributes associated with it including the set of parameters that can be set by the management system and the set of parameters that can be monitored by the management system. As an example each line card object normally has a state attribute associated with it which is one of in service out of service or fault and there are detailed behaviors governing transitions between these states. Another example that is part of a typical information model is the concept of connection trails which are used to model lightpaths. Again multiple types of trails may be defined and each trail has a variety of associated attributes including ones that can be configured as well as others that can be used to monitor the trail s performance. Management Protocols Most network management systems use a master-slave sort of relationship between a manager and the agents managed by the manager. The manager queries the agent to obtain the status of parameters in the network element called the get operation
