Alcatel-Lucent 7450 - PTP Boundary Clock for Frequency and Time

System Management
Basic System Configuration Guide 273
All packets are routed to their destination via the best route as determined in the route table;
see Figure 23. It does not matter which ports are used to ingress and egress these packets
(unless port based time stamping is enabled for higher performance).
Figure 23: Ordinary Master Clock Operation
PTP Boundary Clock for Frequency and Time
The router supports boundary clock PTP devices in both master and slave states. IEEE
1588v2 can function across a packet network that is not PTP-aware; however, the
performance may be unsatisfactory and unpredictable. PDV across the packet network varies
with the number of hops, link speeds, utilization rates, and the inherent behavior of the
routers. By using routers with boundary clock functionality in the path between the grand
master clock and the slave clock, one long path over many hops is split into multiple shorter
segments, allowing better PDV control and improved slave performance. This allows PTP to
function as a valid timing option in more network deployments and allows for better
scalability and increased robustness in certain topologies, such as rings. Boundary clocks can
simultaneously function as a PTP slave of an upstream grand master (ordinary clock) or
boundary clock, and as a PTP master of downstream slaves (ordinary clock) and/or boundary
clocks.
TDM/SyncE
MDA
Central
Clock
1588
Clock
PTP Slave
PTP Slave
PTP Slave
PTP Slave
MDA
PRC
CPM A
B
OSSG740
Packet
Network