Nokia 7705 - 6.4.6.10 PTP Master Clock for Time of Day;Phase Distribution

System Management
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Basic System Configuration Guide
3HE 11010 AAAC TQZZA Edition: 01
Transparent clock functionality is supported for PTP packets over UDP/IP over
Ethernet (with and without VLAN tags).
For high-accuracy 1588 PTP clock recovery, timestamping of incoming and outgoing
messages should be done as close to ingress and egress as possible when the
7705 SAR is acting as a 1588 transparent clock. Edge timestamping is performed on
all packets from all Ethernet ports, including SFP and RJ-45 ports on the faceplate
of the chassis or a port on an installed module.
PTP recovered time accuracy depends on the delay of the forward path and the
reverse path being symmetrical. It is possible to correct for known path delay
asymmetry by using the ptp-asymmetry command to configure an asymmetry delay
setting in nanoseconds per direction for each edge.
To enable transparent clock processing at the node level, configure a PTP clock with
the transparent-e2e clock type (using the clock-type command). Deconfiguring
such a PTP clock will disable transparent clock processing.
6.4.6.10 PTP Master Clock for Time of Day/Phase Distribution
PTP master clock capability for time of day/phase distribution is implemented on the
following platforms:
• 7705 SAR-Ax
• 7705 SAR-H with a GPS Receiver module
• 7705 SAR-Wx variants with a GPS RF port
• 7705 SAR-8 (CSMv2 only) with a GNSS Receiver card
• 7705 SAR-18 with a GNSS Receiver card
Time of day input must be enabled using the use-node-time command before the
node can be used as a PTP grand master clock. GNSS must also be the active
system time reference for nodes that are being used as a grand master clock. When
the use-node-time command is enabled, the PTP master clock uses the system
time as a source of PTP time and can be used for time of day/phase distribution.
When the use-node-time command is disabled, the PTP master clock can be used
for frequency only.