Network Router User Manual

Chapter 6: Packet-over-SONET Configuration Guide
60 SmartSwitch Router User Reference Manual
Note:
In APS terminology, bridge means to transmit identical traffic on both the working
and protecting lines, while switch means to select traffic from either the protecting
line or the working line.
• Unidirectional switching, where one set of line terminating equipment (LTE) can
switch the line independent of the other LTE. Bidirectional switching (where both sets
of LTEs perform a coordinated switch) is not supported.
• Revertive switching. You can enable automatic switchover from the protecting line to
the working line after the working line becomes available.
If the working circuit is disrupted or the bit error rates on the working circuit exceed the
configured thresholds, traffic is automatically switched over to the protecting circuit. Any
physical or logical characteristics configured for the working port are applied to the
protecting port. This includes the IP address and netmask configured for the interface,
spanning tree protocol (STP), per-VLAN spanning tree (PVST), etc.
Configuring Working and Protecting Ports
APS on the SSR requires configuration of a working port and a corresponding protecting
port. You can configure any number of PoS ports. The limit is the number of PoS ports on
the SSR. Any port on any module can be configured for APS. If one module should go
down, the remaining ports on other modules will remain operational.
Note:
The working and protecting ports must reside on the same SSR. You cannot
configure APS operation for working and protecting ports on two different SSRs.
The working port must:
• Be associated with a point-to-point IP interface that is configured with an IP address
and netmask. See “Configuring Packet-over-SONET Links” for the details on
configuring the interface.
The protecting port must:
• Be in the default VLAN. This means that the protecting port must not be configured for
an interface.
• Not have any explicitly configured parameters. The protecting port inherits the
configuration of the working port.
To configure a working and a protecting PoS port, enter the following command in
Configure mode:
Configure working and protecting PoS ports.
sonet set <working-port>
protection 1+1 protected-by
<protecting-port>