The server-provided DCOM class activation facility provides a way for a client to instantiate a new class object on a host machine, obtain its OXID, and obtain one or more IPIDs for the interfaces that it is interested in communicating through, all in one network round-trip. While it is primarily intended for the creation of new objects, the activation facility is free to return the same OXID and IPIDs for all activation requests of a particular class of object; this gives clients an easy way to access a well-known service without having to have a priori knowledge of a specific object (i.e. OXID & IPID) on the host, knowledge which can be invalidated by a reboot or a network failure.
Clients are expected to know beforehand either the CLSID or a file moniker which will result in the creation of the class object that they are interested in communicating with. Clients also have the option of providing a client-side IStorage object which will be used to instantiate and initialize the server-side object.