7210 SAS-M, T, R6, R12, Mxp, Sx, S Basic System
Configuration Guide
System Management
3HE 17358 AAAB TQZZA © 2021 Nokia.
Use subject to Terms available at: www.nokia.com
291
Figure 29 Logical Model for Using PTP/1588 for Network Synchronization on 7210 SAS
Platforms
6.5.8.2 Performance Considerations
Although IEEE 1588v2 can be used on a network that is not PTP-aware, the use of
PTP-aware network elements (boundary clocks) within the packet switched network
improves synchronization performance by reducing the impact of PDV between the
grand master clock and the slave clock. In particular, when IEEE 1588v2 is used to
distribute high-accuracy time, such as for mobile base station phase requirements,
the network architecture requires the deployment of PTP awareness in every device
between the grandmaster and the mobile base station slave.
In addition, performance is also improved by the removal of any PDV caused by
internal queuing within the boundary clock or slave clock. This is accomplished with
hardware that is capable of port-based timestamping, which detects and timestamps
the IEEE 1588v2 packets at the Ethernet interface.
6.5.8.3 PTP End-to-End Transparent Clock
The 7210 SAS devices support PTP end-to-end (E2E) Transparent Clock (TC)
functionality, which allows the node to update the PTP correction fields (CFs) for the
residence time of the PTP message. See Table 31 for a list of platforms that support
this functionality.
sw0455
Central Clock
Time Module
Central Clock
Frequency
Module (EEC)
1588 Master
Ports
1588 Slave
Ports
1588
messages
1588
messages
TO to ports
Nodal reference (TO)
ref1Frequency
recovered
from 1588
message
exchange
ref1 & ref2
allowed
only in PTP
hybrid mode
ref2
ptp
Periodic Time
offset calculated
from 1588 message
exchange
Timestamps
based on central
clock frequency
and offset
Note: This feature is supported only on the 7210 SAS-Sx 1/10GE and 7210 SAS-Sx 10/
100GE.
To Next Page
Loading...
Need help?
General
Weight and Dimensions
