Running A Ber Test - Cisco 10000 Series Configuration Manual

Chapter 5 24-Port Channelized E1/T1 Line Card Configuration

Running a BER Test

You can configure an interface to run a BERT (Bit Error Rate Test). You use a BERT to isolate cable
signal problems in the field, to check network cabling, and to isolate apparent signaling problems in the
field.
Before you begin a network BERT, you need to set up a remote loopback from the far-end (remote)
DSU/CSU (see the
Use the following loopback commands to set the near end devices (CSU/DSUs) to perform loopbacks:
•
•
•
Running an E1 BERT
You can only run a BERT (bit-rate error test) over the full bandwidth of an E1 controller in unframed
mode. To send a BERT pattern on a line card E1 interface, use the following controller configuration
command syntax:
[no] bert pattern pattern interval time [unframed]
Where:
•
•
The no form of the bert command is the default. You can terminate a BERT at any time using the no bert
command.
OL-8834-04
"Specifying Loopbacks" section on page
loopback local line Use this loopback submode on both E1 and T1 ports. This submode configures
—
the line card to loop transmitted packets back as received packets after the framer. The line card also
receives all incoming packets and outgoing packets are also transmitted to the remote network
device.
loopback network—Use this loopback mode on both E1 and T1 ports. This mode configures the
line card to loop packets transmitted from the line card to a remote device back to the line card as
received packets. This loopback mode has the following submodes:
loopback network line—Use this loopback submode on both E1 and T1 ports. This submode
–
configures the line card to loop received packets back to the remote device without first framing
them.
loopback network payload—Use this loopback submode on both E1 and T1 ports. This
–
submode configures the line card to loop received packets back to the remote device after first
framing them.
loopback remote — Operates in T1 mode only (see the
page 5-27). This loopback mode has the following submodes:
loopback remote line—Use this loopback submode on T1 ports to configures the far-end
–
device to loop received packets back to the line card without first framing them.
loopback remote payload—Use this loopback submode on T1 ports to configures the far-end
–
device to loop received packets back to the line card after framing them.
pattern pattern is:
– 2^11—pseudorandom test pattern (32,768 bits long)
– 2^15—pseudorandom O.151 test pattern (32,768 bits long)
– 2^20-O153—pseudorandom O.153 test pattern (1,048,575 bits long)
– 2^20-QRSS—pseudorandom QRSS O.151 test pattern (1,048,575 bits long)
interval time is 1 to 1440 minutes.
5-27).
"Specifying T1 Loopbacks" section on
Cisco 10000 Series Router Line Card Configuaration Guide
Controller Configuration Commands
5-19