Aps Network Configuration Options - Extreme Networks PoS Installation And User Manual

Conversely, in nonrevertive mode, when traffic is active on the protection line and the
working line becomes operational, traffic will remain on the protection line (until either
manual intervention or a failure on the protection line forces a switch back to the
working line).

APS Network Configuration Options

Three basic APS configurations are supported:
• Two-switch configuration, where the working line is terminated in one
BlackDiamond switch and the protection line is terminated in another.
• Two-module configuration, where the working line and the protection line are
terminated in two different SONET modules that reside in the same BlackDiamond
chassis.
• Single-module configuration, where the working line and the protection line are
terminated in the same BlackDiamond SONET module.
Because the two-switch configuration is the most advanced, it is discussed first,
followed by the two simpler configurations.
In the two-switch configuration (see Figure 3-13), the two BlackDiamond switches form
a virtual APS switch. The PoS interface in BlackDiamond #1 is configured to be the
working line, while the PoS interface in BlackDiamond #2 is configured to be the
protection line. The same IP address is configured for both PoS interfaces. In this
example, the common IP address is 192.168.10.1. The use of a common IP address
enables the neighboring PPP router to view the virtual APS switch as a single router
entity; the neighboring router is unaware that its partner is actually two cooperating
switches. Figure 3-14 illustrates the logical PPP connectivity between the virtual APS
router and the neighboring PPP router.
Note: The two-switch configuration is supported only if PPP is configured on the
PoS ports. The two-switch configuration is not supported if HDLC tunneling is
configured on the PoS ports.
Packet Over SONET Module Installation and User Guide
Configuring and Monitoring APS Functions
3-77