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Bionic Buffalo Tech Note #103: Introduction to Pegasus Client Support

When a client application issues an attach request to the local Session object, and the Session object
determines that the request is for a Pegasus server, then the Session object negotiates for a session with
the SRM using a modified version of the

DSM::SessionUU

object. The modified SessionUU object

can handle the special Pegasus dialect of the U-N protocol. Once the session has been negotiated,
however, the local Session object takes a different step: it instantiates two new objects, which we will
call PegasusServiceGateway and PegasusStream. The PegasusServiceGateway is a local impostor,
pretending to be a remote ServiceGatewayUU object. The PegasusServiceGateway has one object in
its directory: the PegasusStream object. The PegasusStream object is another local impostor,
pretending to be a remote

DSM::Stream

object. The client application sees as ServiceGateway and

Stream object, as it normally would in a DSM-CC environment, but those objects aren't really on the
server. They are local, but the application cannot tell the difference. (CORBA makes little distinction
between local and remote objects, from the client application's point of view.)

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