Alcatel-Lucent 7450 Basic System Configuration Manual page 266

Network Synchronization
There is a limit on the number of external PTP clocks to which the ordinary clock slave or
boundary clock will request unicast service (# configured peers) and also a limit to the
number of external PTP clocks to which the ordinary clock master or boundary clock will
grant unicast service (# discovered peers). An association where the boundary clock has a
symmetric relationship with another boundary clock (i.e. they both have the other as a
configured peer) will consume a request and a grant unicast service in each router.
The number of configured Ethernet ports is not restricted.
There are limits to the maximum transmitted and received event message rates supported in
the router. Each unicast IP service established will consume a portion of one of the unicast
message limits. Once either limit is reached, additional unicast service requests will be
refused by sending a grant response with zero in the duration field.
Please refer to the scaling guide for the appropriate release for the specific unicast message
limits related to PTP.
Multicast messages are not considered when validating the unicast message limit. When
multicast messaging on Ethernet ports is enabled, the PTP load needs to be monitored to
ensure the load does not exceed the capabilities. There are several commands that can be used
for this monitoring:
Because the user cannot control the amount of PTP messages being received over the
Ethernet ports, the statistics commands can be used to identify the source of the message load:
Figure 17
clock that is selected to be the master clock. The slave clock will request Announce messages
from all peer clocks but only request Sync and Delay_Resp messages from the clock selected
to be the master clock.
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• 'show system cpu' will identify the load of the PTP software process. If the "capacity
usage" reaches 100%, the PTP software process on the router is at its limit of
transmitting and/or receiving PTP packets.
• 'show system ptp statistics' has aggregate packet rates
• 'show system ptp port' and 'show system ptp port port-id [detail]' display received
packet rates
shows the unicast negotiation procedure performed between a slave and a peer
Basic System Configuration Guide