Alcatel-Lucent 7450 ESS-12 - Figure 19: Ordinary Master Clock Operation

System Management
7450 ESS OS Basic System Configuration Guide Page 241
Figure 10: Peer Clocks
The IEEE 1588v2 standard includes the concept of PTP profiles. These profiles are defined by
industry groups or standards bodies that define how IEEE 1588v2 is to be used for a particular
application.
7450 ESS currently supports two profiles:
• IEEE 1588v2 default profile
• ITU-T Telecom profile (G.8265.1)
In both cases, communications between clocks utilize the Unicast communication procedures of
the IEEE standard. The transport layer uses UDP/IPv4 encapsulation.
When a 7450 ESS receives Announce messages from one or moreconfiguredpeers, it executes a
Best Master Clock Algorithm (BMCA) to determine the state of communication between itself
and the peers. The system uses the BMCA to create a hierarchical topology allowing the flow of
synchronization information from the best source (the Grandmaster clock) out through the
network to all boundary and slave clocks. Each profile has a dedicated BMCA.
Boundary Clock
10.3.1.1
Ordinary Clock
Slave
10.1.1.1
Ordinary Clock
Master
10.3.1.1
Ordinary Clock
Slave
10.2.1.1
7750 SR
10.0.1.1
Peer 10.3.1.1
Peer 10.0.0.1
Configured Peers
Discovered Peers
OSSG736