Management Object Model (MOM) provides services that makes it possible to inspect and adjust the state of the federation programmatically. Most RTIs consist of a Central RTI Component (CRC), which is an executable and Local RTI Components (LRCs), which are libraries that are used by the federates. Services are provided through a C++ or Java API and also using Web services. In the C++ and Java APIs, services are invoked using calls to an instance of the RTI Ambassador class. The RTI delivers information to a federate using callbacks, which are delivered using calls to an instance of the Federate Ambassador class. In the Web Services API, defined using WSDL, calls are made, and callbacks are fetched, by the federate using Web Services requests and responses. The service group descriptions below focus on key services. Exceptions and advisories are not included. Federation Management Services The purpose of Federation Management services, described in chapter 4 of the HLA Interface Specification, is to manage Federation Executions as well as federation-wide operations such as Synchronization Points and Save/Restore. One set of Federation Management services manages the connection to the RTI, the federation execution and the set of joined federates. Key services are: Connect and Disconnect from the RTI CreateFederationExecution and DestroyFederationExecution that are used to create and destroy a federation execution JoinFederationExecution and ResignFederationExecution that are used by a federate to join and resign a federation execution. ConnectionLost, that is used by the RTI to inform a federate that it has lost its connection to the federation execution due to a fault ListFederationExecutions that is used to retrieve a list of available federation executions for an RTI Another set of services relates to synchronization points. These are federation-wide events where all, or selected federates are required to complete an operation, such as initializing a scenario, before the execution can continue. Key services are: RegisterFederationSynchronizationPoint that is used to register a synchronization point AnnounceSynchronizationPoint that is used by the RTI to inform federates that a synchronization point has been registered SynchronizationPointAchieved that is used by a federate to indicate that it has achieved a synchronization point FederationSynchronized that is used by the RTI to Inform federates that the federation is synchronized, i.e. all federates have achieved the synchronization point. Yet another set of service relates to saving and restoring a federation execution. A save operation requires both the RTI and each federate to perform