Cisco ONS 15454 SDH Manual page 14

11.4.2 IP-Encapsulated Tunnels
11.4.2 IP-Encapsulated Tunnels
An IP-encapsulated tunnel puts an RS-DCC in an IP packet at a source node and dynamically routes the
packet to a destination node. A traditional DCC tunnel is configured as one dedicated path across a
network and does not provide a failure recovery mechanism if the path is down. An IP-encapsulated
tunnel is a virtual path, which adds protection when traffic travels between different networks.
IP-encapsulated tunneling has the potential of flooding the DCC network with traffic resulting in a
degradation of performance for CTC. The data originating from an IP tunnel can be throttled to a
user-specified rate, which is a percentage of the total RS-DCC bandwidth.
Each ONS 15454 SDH supports up to ten IP-encapsulated tunnels. You can convert a traditional DCC
tunnel to an IP-encapsulated tunnel or an IP-encapsulated tunnel to a traditional DCC tunnel. Only
tunnels in the DISCOVERED status can be converted.
Converting from one tunnel type to the other is service-affecting.
Caution
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.
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
Port 1 of the STM-1 card.
Figure 11-4
VC4 Drop
Class 5
Switch
Test Set
VC4 Monitor
Monitor circuits cannot be used with Ethernet circuits.
Note
Cisco ONS 15454 SDH Reference Manual, R8.5
11-14
VC4 Monitor Circuit Received at an STM-1 Port
ONS 15454 SDH
Node 1
XC
Port 1
STM-1
STM-N
Port 2
Figure 11-4 shows an example of a monitor circuit. At
Figure 11-4 is used to monitor VC4 traffic received by
ONS 15454 SDH
Node 2
XC
STM-N
Chapter 11 Circuits and Tunnels
STM-N
78-18119-01