RFC 3550 specifies one media-timestamp in the RTP data header and a mapping between such timestamp and a globally synchronized clock, carried as RTCP timestamp mappings.

The NTP TIMESTAMPS in the SR are ASSUMED to be synchronized between all media senders within a single session. If the media sources come from the same network source, this is OBVIOUSLY not an issue. RECEIVER(s) synchronize to the sender, the only solution feasible for multicast.

Experience has shown that all other cross-media, cross-host SCHEMES end up doing clock synchronization, usually inferior to NTP and application-specific.

RFC 3550 specifies one media-timestamp in the RTP data header and a mapping between such timestamp and a globally synchronized clock, carried as RTCP timestamp mappings.

The NTP timestamps in the SR are assumed to be synchronized between all media senders within a single session. If the media sources come from the same network source, this is obviously not an issue. Receiver(s) synchronize to the sender, the only solution feasible for multicast.

Experience has shown that all other cross-media, cross-host schemes end up doing clock synchronization, usually inferior to NTP and application-specific.