The record interface of the server allows a client start a recording of any of the media used in conference, to specify the duration of the recording, to specify one, many, or all of the source streams, and to add a title and text description of the recording. If more than one media is selected for a source, then the user may choose to have time-based synchronisation between those streams at the server. This will enable synchronisation within the playback mechanisms.
The server system collects all or some of the streams of media for a conference, and a client allows the user to select which media to record and then instructs the server to record them. The client does not need to be part of the conference. With the server listening to the media tool session messages or observing the source addresses of incoming data each media of a conference, the server can decide who is in each conference. Another feature of the server is the ability to allow synchronisation between the incoming streams. In this way playback can be presented to the user with the media streams for a source being synchronised.
A client connected to the record interface allows the user to select a media to record, and then instructs the server to record that stream. The server can inform its clients who it is currently recording a conference in order to stop more than one client attempting to record the same media within that conference. It is expected that a new client will be started for each different multicast conference. Figure 9.3 shows that the media tools send and receive data via IP multicast, and that the server under instruction from the client receives that multicast data and records it.
Using this client/server configuration, many sites may have servers which are able to record and playback conferences. These sites may choose to record data for any authorised user on the network, not just for local users. It is not necessary any special designated site to be the conference recording hub for the whole of the MBone. With full deployment, there could be a large collection of servers on the Internet. A client can connect to a server anywhere on the network to request a recording.
Next: Playback Up: Server Interfaces Previous: Server Interfaces Jon CROWCROFT