Juniper EX9251, Руководство по оборудованию

Страница: 112 / 217

EX9251 switches support external clock synchronization for Synchronous Ethernet and external inputs.
The connections to the switch are made through the front panel.
Figure 48 on page 103 shows the ports
that are used to connect the switch to external clocking and timing devices.
Figure 48: Ports Used to Connect the Switch to External Clocking and Timing Devices
1
—
PTP grandmaster clock (GM/PTP) port 4
—
10 MHz GPS input and output timing ports
2
—
BITS ports with LEDs 5
—
1PPS GPS input and output timing ports
3
—
Time of day (ToD) port with LED
Connecting 1-PPS and 10-MHz Timing Devices to the Switch
The switch has four SubMiniature B (SMB) connectors that support 1-PPS and 10-MHz timing devices.
NOTE: Ensure that a cable of 3 m or less in length is used for the 10-MHz and 1-PPS connectors.
To connect the SMB coaxial cable to the external clocking input port:
1. Connect one end of the SMB coaxial cable to either the 1-PPS SMB connector or the 10-MHz SMB
connector on the switch.
2. Connect the other end of the SMB coaxial cable to the 10-MHz or 1-PPS source network equipment.
NOTE: Ensure that the 10-MHz or 1-PPS source network equipment contains low voltage
complementary metal oxide semiconductor (LVCMOS) or is compatible with low-voltage
(3.3 V) transistor–transistor logic (LVTTL).
103