Telestream PRISM MPI2-10, User Manual

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PTP Operational Overview
Multicast, Unicast, and Mixed Communication Modes
PRISM MPI2-10-MPX2-10 User Manual
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sends several grant requests to the master requesting specific rates for each message
type. If the master accepts the grant requests, it sends grant acknowledges. If the
master denies the grant, the slave may send a new grant request at a lower rate. This
process may continue for several iterations until the master and slave agree on a rate.
The master and slave then start exchanging the PTP messages. If the master cannot
support any of the rates requested by the slave, then the slave cannot lock to the
master.
Mixed-Mode System Messages
In Mixed Mode systems, some messages are Multicast and some are Unicast. For the
SMPTE ST2059 profile, the Announce and Sync messages are sent as Multicast. This
allows devices to discover the active master. The Delay Request messages are
configured as Unicast, in some case with negotiation, and in other cases without
negotiation.
SMPTE Profile System Messages
For SMPTE profile systems, a given domain must use one type of message for all
Announce, Sync, and Follow-up messages. Therefore, all masters and slaves on that
domain must be configured for either Multicast or they all must be configured for
Unicast.
For SMPTE mixed mode, the Announce, Sync, and Follow up messages are configured
as Multicast, whereas the delay requests can be Multicast, Unicast, or Unicast without
negotiation. To use this combination with an SPG8000A master clock generator, set the
master and slave to any of the modes: Multicast, Mixed, or Mixed without negotiation.
The masters support all of the slave modes simultaneously.