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CHAPTER 3: Configuration
S
WITCH
SW2-1 C
LOCK
M
ODE
This switch is used to select the timing source for transmitting data to the network.
External clocking is available only in unframed mode (DTE data rate of 1.544
Mbps).
Table 3-9. Clocking and Framing Modes.
Function
SW2-1
SW2-2
Clocking Mode
Framed Mode
Off
Don’t Care
Network
(ESF/D4)
On
Don’t Care
Internal
Unframed Mode
Off
Don’t Care
Network
On
Off
Internal
On
On
External
NOTE
When using the Micro T1 CSU/DSU to terminate the telephone
company’s T1 service, the Micro T1 CSU/DSU must be set to network
clock. When using the CSU/DSU as a high-speed short-range modem,
one unit of the link must be configured for Internal Clock mode, and
the unit on the opposite end must be configured for Network Clock
mode.