DVRMP runs on top of RTP[#!rtp!#] and UDP. All DVRMP messages are multicast. As in Parnes' proposal, we use RTP data packets as is, for data. If reliability is needed, the RTP PT field is used to indicate SRM, otherwise it simply conveys normal data.
The SSRC is the source VR application. the CSRC can be used for input from specific devices.
We use RTCP as is for session quality reports, and respect the PARNES protocol for reliability:
More than one multicast group is used. Session messages are used within one multicast group to advertise the existence of participants and objects. Objects have owners. At any one time, the owner is the source of the session messages about an object.
Messages can be marked as reliable or not reliable, however, this is not binding on recipients. Recipients can operate the repair algorithm on reliable object messages in the normal way. Other messages are deemed ephemeral, and can be lost (or discarded) at will8.5.
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