Datasheet

11-14
Cisco ONS 15454 SDH Reference Manual, R7.0
October 2008
Chapter 11 Circuits and Tunnels
11.5 Multiple Destinations for Unidirectional Circuits
11.5 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 have its 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.
11.6 Monitor Circuits
Monitor circuits are secondary circuits that monitor traffic on primary bidirectional circuits. Monitor
circuits can be created on E1 or STM-N cards. Figure 11-4 shows an example of a monitor 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 Figure 11-4 is used to monitor VC4 traffic received by
Port 1 of the STM-1 card.
Figure 11-4 VC4 Monitor Circuit Received at an STM-1 Port
Note Monitor circuits cannot be used with Ethernet circuits.
11.7 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 The XC-VXC-10G cross-connect card supports VC switching based on SF and SD bit error rate (BER)
thresholds. The XC-VXL-10G and XC-VXL-2.5G cross-connect cards do not support VC switching
based on SF and SD BER thresholds, and hence, in the SNCP path protection Selectors tab, the SF BER
Level and SD BER Level columns display "N/A" for these cards.
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