 or the profile of the VCs that are supported by a trail on the VP layer. Access profiles are contained in the appropriate TTPs. The operations system of an ATM switch performs a "get" operation on the pro- file object within a TTP object to determine the number of identifier bits and ATM connections that are supported. To discover the TTP object to which an interface refers, the operations system of an ATM switch can perform a get on the pointer attribute. 3 The three dots at the middle of the diagram are an ellipsis. 3 ATM Network Management - The ATM Forum Model Corporate/enterprise Carrier network Carrier network network management system management system management system Public ATM Public ATM Public ATM device network network network Public/private network boundary Figure 3.3 ATM Forum Management model. Each ATM cross connection is represented by a cross connection object. These objects are contained in the fabric object that represents the cross connection matrix. To create a cross connection object, the operations system of an ATM switch sends a connect action to the ATM fabric. This action identifies the CTP objects at the ends of the connection or includes a description of the ATM traffic if there is no CTP and the latter allows an appropriate CTP object to be created. To remove a cross connection, the operations system sends a disconnect action to the ATM fabric. 3.3 The ATM Forum Management Model The Network Management Working Group of the ATM Forum has developed an end-to-end generic management model that encompasses private and public net- works and lays out standards for interworking between them. The model defines gateways between SNMP and CMIP systems, and between standards-based and pro- prietary systems. Five key management interfaces are defined in this model, labelled M1-M5. M1 is concerned with the management of the end-user equipment connecting to either private or public switches. M2 undertakes management of private ATM switches and networks. Private ATM network management is addressed th