3Com SuperStack II PathBuilder S330 Reference Manual page 135

Figure 113 Configuring the CBR Serial Port
The Selected DS0 Channels listed at the top of the CBR Serial Port Configuration
menu initially lists None. After you build a virtual circuit on the CBR serial port, this
listing updates automatically to reflect the DS0 channels selected for the circuit.
4 Set the following port configuration parameters as desired:
SCT Clock Source — The type of input clock service configured for the port
interface.
Recovered — A non-required network-wide synchronization technique used
to regenerate the input service clock. Adaptive timing uses a buffer depth
indicator at the receiver to adjust the line rate: the fuller the buffer, the faster
the line rate; the emptier the buffer, the slower the line rate.
Internal — Configures the port interface to use the internal clock as the
timing source.
SCR Clock Source — The type of output clock service configured for the port
interface.
Internal — Configures the port interface to use the internal clock as the
timing source.
Adaptive — A non-required network-wide synchronization technique used to
regenerate the input service clock. Adaptive timing uses a buffer depth
indicator at the receiver to adjust the line rate: the fuller the buffer, the faster
the line rate; the emptier the buffer, the slower the line rate.
SCTE Clock Source — The Rx timing source for the serial interface: Echo Clock
from DTE or DCE Transmit Clock.
Configuring the CBR Module 121