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SessionMappers

   The mmstream.session.SessionMapper interface is simple: it comprises the session2Packet method, which derives a transmittable description of a Session, and the packet2ProtoSession method, which uses a received session description packet to initialise a ProtoSession object.
ProtoSession objects contain all the information that is necessary to parametrise a Session object for participation in the described multimedia session. The information comprises for example the type of the communicated payload, the transmission protocol used, and network addresses. In addition, they contain the cnames of the session's initiator and all known participants.

  The mmstream.session.TOMS_SessionMapper class implements a small and simple session description protocol, which encodes the session parameters according to a type-length-value coding scheme. It was developed for testing the session description import and export mechanisms, and is tailored to the needs of the architecture. It conveys the connection type (currently either UDP or UDP_MULTICAST), the data and control addresses, the maximum transfer unit supported by the connection type, the transmission protocol (currently only RTP), profile-specific parameters, the payload type, the current state of the application (mainly RUNNING or FINISHED), the cname of the session's initiator, the cname of the session participant that generated the session description packet, and a session ID, the combination of which with the initiator's cname must be unique.



tspeuker@cip.informatik.uni-erlangen.de