User guide
Packet Over SONET Module Installation and User Guide 3-83
Configuring and Monitoring APS Functions
Figure 3-17: Redundant switch configuration with APS
While these two configurations appear similar, the significant difference between them
is that the BlackDiamond switches in Figure 3-17 appear to the rest of the network as
two PoS interfaces (IP addresses 192.168.10.1 and 192.168.20.1), as opposed to the four
PoS interfaces shown in Figure 3-16 (IP addresses 192.168.10.1, 192.168.20.1, 192.168.10.3,
and 192.168.20.3). The configuration in Figure 3-17 enables customers to purchase half
the SONET bandwidth without sacrificing resiliency. In fact, the APS configuration
offers increased resiliency by virtue of not reducing maximum throughput as a result of
a single line or switch failure. Furthermore, if the extra bandwidth is needed, two larger
bandwidth interfaces are more efficient than four smaller bandwidth interfaces, due to
suboptimal load-balancing.
PoS_016
BlackDiamond 1
Virtual APS router
1234AB5678
Working line
Group 1
Protection line
Group 1
Working line
Group 2
Protection line
Group 2
1234AB5678
BlackDiamond 2
Ethernet
ADM
2
ADM
1
192.168.10.1
192.168.20.1
192.168.10.1
192.168.20.1