Chapter 38: APS

APS protects SONET/SDH lines from linear bidirectional failures. The NEs in a SONET/SDH network constantly monitor the health of the network. When a failure is detected, the network proceeds to transfer, or switch over, live traffic from the active, or working line, to the standby, or protection line. The transfer occurs quickly to minimize traffic loss. The traffic remains on the protection line until the fault on the working line clears, at which time the traffic can optionally revert to the working line.

In a 1+1 APS architecture, the active OC-n signal is transmitted to both the working and protection ports, so the same payloads are transmitted identically to the working and protection ports in the egress direction. The working and protection signals are selected independently in the ingress direction.

Overview

APS overview

APS overview

Switching modes

MLPPP

APS port configurations

SC APS

MC APS

APS on channelized ASAP MDAs

APS on channelized CES MDAs

APS on multilink bundles

1+1 APS configuration example

Configuring SAPs on APS-protected ports

APS management procedures

Workflow to manage APS

To create an SC APS group

To create an MC APS group

To create an SC APS IMA or MLPPP bundle

To create an MC APS MLPPP bundle

To change the operational state of an SC APS channel

To delete an SC APS group

To delete an SC APS bundle

To delete an MC APS group or bundle