Integration of Network Communication

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Integration of Network Communication

A framework based on the data-flow principle can be easily extended by network communication classes. However, the code and the responsibility for networking can be placed in different classes:

Gibbs [Gib91, p. 11--12,] suggests specialised sink and source classes. On the sender side, a sink object, connected to a source object, packetizes and transmits data over the network. On the receiver side, the object that accepts data packets from the network, acts as a source object and forwards the received data through its output ports to filters and sinks. The example of an audio talk application presented in Figure visualizes this approach.

Figure: An audio talk application using specialised sink and source objects for network communication.
Another possible approach, which is depicted in Figure , employs specialised connector objects that can connect a source object and sink objects across a network.

Figure: An audio talk application using specialised connector objects for network communication.

If the presentation start time

and duration

of the individual media elements

is not contained directly in the encoding of the

or known implicitly, the network communication objects must transmit the timing information together with the transport representation of the

by means of appropriate protocols such as RTP described in Section

In addition, the class collection must be enriched by classes that can cooperate with the QoS control interface of the network system.

Besides, the collection must incorporate classes that can communicate session descriptions to remote sites.

tspeuker@cip.informatik.uni-erlangen.de