ADC Telecommunications, Inc.
378 CHAPTER 18: CONFIGURING CABLE MODEM TERMINATION SYSTEMS
Plant-delay
The Plant-delay parameter specifies the maximum round-trip propagation
delay in the cable plant. This value is u sed to adjust the map lead time. It is
recommended that a low value be used to reduce cable modem access delay.
■For a cable plant of 25 miles, the recommended value is 400.
■For a cable plant of 100 miles, the recommended value is 1600.
You set the plant delay for the current cable interface by performing the
following tasks.
PLL State
Phase-locked loops (PLL) are circuits that hunt and synchronize to an external
signal. The PLL State value should be zero; this indicates normal operation. A
PLL State value of non-zero, indicates a malfunction of the CMTS module.
The PLL state is displayed as part of the show interface cable <c/s/i> mac
display. You can also verify the PLL State by performing the following task.
Task Command
1. Enter interface cable mode. interface cable <c/s/i>
2. Configure plant delay. plant-delay <value>
Task Command
1. Enter interface cable mode. interface cable <c/s/i>
2. Verify PLL state of the current
cable interface.
show interface cable <c/s/i> pll-state