3Com 4210 PWR Configuration Manual page 372

370 C 35: NTP C
HAPTER ONFIGURATION
Symmetric peer mode
Figure 111 Symmetric peer mode
Active peer
In peer mode, both sides
can be synchronized to
each other
In the symmetric peer mode, the local Switch 4210 serves as the symmetric-active
peer and sends clock synchronization request first, while the remote server serves
as the symmetric-passive peer automatically.
If both of the peers have reference clocks, the one with a smaller stratum number
is adopted.
Broadcast mode
Figure 112 Broadcast mode
Server
Works in the server mode
automatically and sends
responses
Multicast mode
Figure 113 Multicast mode
Server
Works in the server mode
automatically and sends
responses
Passive peer
Network
Clock synchronization
request
Response
Synchronize
Network
Broadcast clock synchronization
packets periodically
Client/server mode
request
Response
Broadcast clock synchronization
packets periodically
Network
Multicast clock synchronization
packets periodically
Client/server mode
request
Response
Multicast clock synchronization
packets periodically
Works in passive peer
mode automatically
Client
Initiates a client/server mode
request after receiving the
first multicast packet
Obtains the delay between the
client and server and works in
the multicast client mode
Receives multicast packets and
synchronizes the local clock
Client
Initiates a client/server mode
request after receiving the
first multicast packet
Obtains the delay between the
client and server and works in
the multicast client mode
Receives multicast packets and
synchronizes the local clock