10-12
Cisco ONS 15454 SDH Reference Manual, R5.0
April 2008
Chapter10 Circuits and Tunnels
10.5 Multiple Destinations for Unidirecti onal Circuits
10.5 Multiple Destinations for Unidirectional Circuits
Unidirectional circuits can have multiple destinations for use in broadcast circuit schemes. In broadcast
scenarios, one source transmits traffic to multiple destinations, but traffic is not returned back to the
source. When you create a unidirectional circuit, the card that does not have its backplane receive (Rx)
input terminated with a valid input signal generates a loss of signal (LOS) alarm. To mask the alarm,
create an alarm profile suppressing the LOS alarm and apply it to the port that does not have its Rx input
terminated.
10.6 Monitor Circuits
Monitor circuits are secondary circuits that monitor t raffic on primary bidirectional circuits. Monitor
circuits can be created on E1 or STM-N cards. Figure 10-4 shows an example of a moni tor circuit. At
Node 1, a VC4 is dropped from Port 1 of an STM-1 card. To monitor the VC4 traffic, test equipment is
plugged into Port 2 of the STM-1 card and a monitor circuit to Port 2 is provisioned in CTC. Circuit
monitors are one-way. The monitor circuit in Figure10-4 is used to monitor VC4 traffic received by
Port 1 of the STM-1 card.
Figure 10-4 VC4 Monitor Circuit Received at an STM-1 Port
Note Monitor circuits cannot be used with Ethernet circuits.
10.7 SNCP Circuits
Use the Edit Circuits window to change SNCP selectors and switch protection paths. In the SNCP
Selectors subtab on the Edit Circuits window, you can:
•View the SNCP circuit’s working and protection paths.
•Edit the reversion time.
•Set the hold-off timer.
•Edit the Signal Fail (SF)/Signal Degrade (SD) bit error rate (BER) thresholds.
Note In the SNCP Selectors tab, the SF Ber Level and SD Ber Level columns display “N/A” for those nodes
that do not support VC low-order signal BER monitoring. In Software Rel ease 5.0, only the
Cisco ONS 15310-CL supports VC low-order signal BER monitoring.
STM-1 STM-N
XC
ONS 15454 SDH
Node 1
STM-N STM-N
XC
ONS 15454 SDH
Node 2
VC4 Drop
VC4 Monitor
Test Set
Port 1
Port 2
Class 5
Switch
71678