Juniper JUNOS 10.1 - CONFIGURATION GUIDE 1-2010 Configuration Manual page 992

JUNOS 10.1 Network Interfaces Configuration Guide
If you are using nonrevertive APS, you can use the
switch the circuit manually to being the working circuit or to override the revert timer
(configured with the
Configuring Unidirectional Switching Mode Support
You can configure interoperation with SONET/SDH Line Terminating Equipment
(LTE) that is provisioned for unidirectional linear APS in 1+1 architecture on the
following interfaces:
By default, APS supports only SONET/SDH LTE that is provisioned for bidirectional
mode.
In bidirectional switching mode, the working interface switches to the protect interface
for both receipt and transmission of data, regardless of whether the signal failure is
in the transmit or receive direction.
In true unidirectional mode, the working interface switches to the protect interface
only for the direction in which signal failure occurs; for example, if there is a signal
failure in the transmit direction, the working interface switches over to the protect
interface for transmission but not receipt of data. When the protect interface operates
in unidirectional mode, the working and protect interfaces must cooperate to operate
the transmit and receive interfaces in a bidirectional fashion.
The JUNOS Software does not support true unidirectional mode. Instead the software
supports interoperation with SONET/SDH LTE provisioned for unidirectional switching.
This means that the SONET/SDH LTE on the router receives and transmits on one
interface, even when you configure unidirectional support. The JUNOS implementation
of unidirectional mode support allows the router to do the following:
To configure unidirectional mode support, include the
statement, at the
NOTE: On interfaces with unidirectional APS support configured, revertive mode
and load sharing between circuits are not supported.
922
Configuring SONET/SDH Physical Interface Properties
revert-time
Unchannelized OC3, OC12, and OC48 SONET/SDH interfaces on T Series routers
SONET/SDH interfaces on the M40e router
ATM over SONET interfaces
Accept a unidirectional mode as valid
Trigger the peer (ADM) selector to switch receive from working interface to
protect interface or the reverse
Not send reverse requests to the far end (ADM)
[edit interfaces interface-name sonet-options aps]
[edit interfaces interface-name sonet-options aps]
switching-mode unidirectional;
request working
statement).
switching-mode unidirectional
statement to
hierarchy level: