Comtech EF Data CDM-625A Installation And Operation Manual page 627

CDM-625A Advanced Satellite Modem
Appendix K
Symbol Designation
M
S
Grandmaster
As shown in Figure 16-14:
• The first segment is between the RNC/BSC and the CDM-625A 'A' (near-end modem)
LAN port. In this segment, the RNC/BSC is the master, and the near-end modem LAN
port is the slave.
Using the CDM-625A 'A' front panel or its Web Server Interface, set the PTP
Grandmaster on this near-end modem as LAN.
• The second segment is from the CDM-625A 'A' (near-end modem) WAN port to the
CDM-625A 'B' (distant-end modem) WAN port, in which the near-end modem WAN port
is the master and the distant-end modem WAN port is the slave.
Using the CDM-625A 'B' front panel or its Web Server Interface, set the PTP
Grandmaster on this distant-end modem as WAN.
Accordingly, the third segment between the CDM-625A 'B' (distant-end modem) LAN
port and the BTS defines the distant-end modem's LAN port as the master and the BTS
as the slave.
As configured here, each modem has established independent Wireless Receiver/Transmitter
(WRT) protocol segments – one for LAN and other one for WAN. This defines the boundary clock
time distribution configuration, where the slave to one interface provides a master clock to the
other interfaces.
Function
Master The Master device maintains the clocks.
Slave The Slave device synchronizes its clock to the Master device's clock.
The r oot t iming r eference t hat t ransmits s ynchronization i nformation t o t he c locks
residing on its network segment.
Figure 16-14. PTP Master/Slave Assignment Example
K–17
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MN-CDM625A