Cisco Cisco 1900 2900 3900 Series 4-Port Gigabit Ethernet HS-WIC with PoE
Verifying the Configuration
6
Configuring the Cisco 1-, 2-, and 4-port Serial Network Interface Modules for Cisco 4400 Series ISRs
Example:
Router(config-if)# pulse-time 3
Monitoring DSR As a Line Up/Down Indicator
When the serial interface is operating in DTE mode, by default, it monitors the Data Carrier Detect
(DCD) signal as the line up/down indicator. The attached DCE device sends the DCD signal by default.
When the DTE interface detects the DCD signal, it changes the state of the interface to up.
In some configurations, such as an the Synchronous Data Link Control (SDLC) multidrop environment,
the DCE device sends the Data Set Ready (DSR) signal instead of the DCD signal, which prevents the
interface from coming up. To tell the interface to monitor the DSR signal instead of the DCD signal as
the line up/down indicator, configure the ignore dcd command in the interface configuration mode.
the DCE device sends the Data Set Ready (DSR) signal instead of the DCD signal, which prevents the
interface from coming up. To tell the interface to monitor the DSR signal instead of the DCD signal as
the line up/down indicator, configure the ignore dcd command in the interface configuration mode.
Example:
Router(config-if)# ignore dcd
Ignoring Input Signals
You can configure the ignore [cts|dcd|dsr|dtr|rts] command to ignore the incoming signals that may
be flapping due to certain cabling issues. When the ignore [cts|dcd|dsr|dtr|rts] command is config-
ured, a signal is automatically seen as asserted.
ured, a signal is automatically seen as asserted.
Example:
Router(config-if)# ignore [cts|dcd|dsr|dtr|rts]
Note
For the ignore command, the availability of cts, dcd, dsr, dtr and rts keyword options depend on whether
the interface is a DTE or DCE interface.
the interface is a DTE or DCE interface.
Inverting the Clock Signal
Systems that use long cables or cables that are not transmitting the TxC (clock) signal might experience
high error rates when operating at higher transmission speeds. If a Serial NIM port is reporting a high
number of error packets, a phase shift might be the problem; inverting the clock might correct this phase
shift.
high error rates when operating at higher transmission speeds. If a Serial NIM port is reporting a high
number of error packets, a phase shift might be the problem; inverting the clock might correct this phase
shift.
When the EIA/TIA-232 interface is a DTE, the invert-txclock command inverts the TxC signal the DTE
receives from the remote DCE. When the EIA/TIA-232 interface is a DCE, the invert-txclock command
inverts the clock signal to the remote DTE port. You can use the no invert-txclock command to change
the clock signal back to its original phase.
inverts the clock signal to the remote DTE port. You can use the no invert-txclock command to change
the clock signal back to its original phase.
Example:
Router(config-if)# invert txclock
Verifying the Configuration
Follow these tasks to verify your configuration:
•
•
•