PRISM MPI2-25 and MPX2-25 Media Analysis Platform User Manual
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Communication Mode
: There are three basic message modes for PTP:
Multicast, Unicast, and mixed Multicast and Unicast. For full Multicast or
Unicast modes, all of the PTP messages are sent in the selected mode type.
NOTE.
The PRISM monitor currently supports Multicast communication mode
and SMPTE mixed mode without negotiation. In later firmware releases, other
communication modes will be supported.
For some profiles, such as some telecom profiles and the SMPTE ST2059
profile, a mixture of Multicast and Unicast are allowed. On the SMPTE
profile unique mixed mode, the Announce and Sync messages are sent as
multicast. However, the Delay request and Delay Response messages are sent
as Unicast.
Some points to understand about communication modes:
o
Whatever mode is chosen, the master and slave must match or be
compatible
o
Multicast and Mixed mode may need IGMP joins and leaves Full
Unicast must have the master address in all slave AMTs
o
Unicast without negotiation does not allow master to regulate load
o
Two masters can be used on different domains to serve slaves on
different communication modes
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Delay Mechanism
: Shows the delay mechanism mode being used:
NOTE.
The PRISM monitor currently supports only the End-to-End delay
mechanism.
o
End-to-End
: In this mode, the sync, follow up, delay request and delay
response messages go through the network all the way between the
master and slave. End-to-End mode is useful in PTP networks where
some or all devices are not PTP aware.
o
Peer-to-Peer
: In this mode, the Pdelay request and Pdelay response
messages are local to each link in the network. Each device determines
the local link and device delays. The sync message from the master then
collects the corrections as it propagates from the master to slave. Peer-
to-Peer mode is useful in PTP networks where the routing configuration
changes. For Peer-to-Peer mode to work well, all of the devices need to
be PTP aware.
