Juniper JUNOS 10.1 - CONFIGURATION GUIDE 1-2010 Configuration Manual page 993

To restore the default behavior, include the
at the [edit interfaces interface-name sonet-options aps]
[edit interfaces interface-name sonet-options aps]
switching-mode bidirectional;
Configuring APS Timers
The protect and working routers periodically send packets to their neighbors to
advertise that they are operational. By default, these advertisement packets are sent
every 1000 milliseconds. A router considers its neighbor to be operational for a
period, called the hold time, that is, by default, three times the advertisement interval.
If the protect router does not receive an advertisement packet from the working
router within the hold time configured on the protect router, the protect router
assumes that the working router has failed and becomes active.
APS is symmetric; either side of a circuit can time out the other side (for example,
when detecting a crash of the other). Under normal circumstances, the failure of the
protect router does not cause any changes because the traffic is already moving on
the working router. However, if you had configured
router failed, the working router would enable its interface.
To modify the advertisement interval, include the
interfaces interface-name sonet-options aps]
[edit interfaces so-fpc/pic/port sonet-options aps]
advertise-interval milliseconds;
To modify the hold time, include the
hierarchy level:
sonet-options aps]
[edit interfaces so-fpc/pic/port sonet-options aps]
hold-time milliseconds;
The advertisement intervals and hold times on the protect and working routers can
be different.
Configuring Link PIC Redundancy
Link state replication, also called interface preservation, is an addition to the SONET
Automatic Protection Switching (APS) functionality that helps promote redundancy
of link PICs used in LSQ configurations, providing MLPPP link redundancy at the port
level.
Link state replication provides the ability to add two sets of links, one from the active
SONET PIC and the other from the standby SONET PIC, to the same bundle. If the
active SONET PIC fails, links from the standby PIC are used without link renegotiation.
All the negotiated state is replicated from the active links to the standby links to
prevent link renegotiation. For more information about LSQ configurations, see the
JUNOS Services Interfaces Configuration Guide.
Chapter 61: Configuring SONET/SDH Interfaces
switching-mode bidirectional
request protect
advertise-interval
hierarchy level:
hold-time at the [edit interfaces interface-name
Configuring SONET/SDH Physical Interface Properties
statement,
hierarchy level:
and the protect
at the
[edit
923