Receiving Bert Patterns; Enabling Local Or Network Loopback - Juniper PHYSICAL LAYER - CONFIGURATION GUIDE V11.1.X Configuration Manual

Receiving BERT Patterns

The router can receive BERT patterns from a remote device at the T1/E1 over
SONET/SDH VT and T1/E1 over T3 layers. To receive BERT patterns, configure the
interface on the router for network payload loopback and the remote interface to
use the line clock. Inaccurate results might occur if you use other loopback modes
or clock sources.
When the router is synchronized with and receiving BERT patterns from a remote
device, the router records the number of bit errors and the number of bits received.
To view these statistics, issue the show controllers sonet command.

Enabling Local or Network Loopback

You can enable loopback tests on the router at the following layers in the interface
stack:
See "Interface Stack" on page 113 for a description of the layers.
To enable local or network loopback:
1.
2.
loopback
Specify the duration of the test in the range 1–1440 minutes.
Optionally, specify the unframed keyword to overwrite the framing bits.
Example
host1(config-controll)#path 12 ds3 2 t1 14 bert pattern 2^11 interval 10
unframed
Use the no version to stop the test that is running.
See path ds3 t1 bert.
SONET/SDH section layer
T1/E1 over SONET/SDH VT layer
T3 layer
T1/E1 over T3 layer
Select a controller.
Configure local or network loopback at the desired layers in the interface.
Use to configure the type of loopback at the SONET/SDH section layer.
Specify one of the following options:
local Loops the data back toward the router; on supported line modules,
also sends an alarm indication signal (AIS) out toward the network.
network Loops the data toward the network before the data reaches the
frame.
Chapter 4: Configuring Channelized OCx/STMx Interfaces
Testing Interfaces
147