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JUNOS 10.1 Network Interfaces Configuration Guide
Interface Diagnostics
BERT allows you to troubleshoot problems by checking the quality of links. You can
configure any of the following interfaces to execute a BERT when the interface
receives a request to run this test: E1, E3, T1, T3; the channelized DS3, OC3, OC12,
and STM1 interfaces; and the channelized DS3 IQ, E1 IQ, and OC12 IQ interfaces.
A BERT test requires a line loop to be in place on either the transmission devices or
the far-end router. The local router generates a known bit pattern and sends it out
the transmit path. The received pattern is then verified against the sent pattern. The
higher the bit error rate of the received pattern, the worse the noise is on the physical
circuit. As you move the position of the line loop increasingly downstream toward
the far-end router, you can isolate the troubled portion of the link.
To configure BERT, you must configure the duration of the test, the bit pattern to
send on the transmit path, and the error rate to monitor when the inbound pattern
is received.
To configure the duration of the test, the pattern to send in the bit stream, and the
error rate to include in the bit stream, include the
bert-error-rate
interface-type-options]
By default, the BERT period is 10 seconds. You can configure the BERT period to last
from 1 through 239 seconds on some PICs and from 1 through 240 seconds on other
PICs.
rate
to a bit error rate from 10
algorithm
enter a
[edit interfaces t1-0/0/0 t1-options]
user@host# set bert-algorithm ?
Possible completions:
For specific hierarchy information, see the individual interface types.
146
Interface Diagnostics
statements, respectively, at the
hierarchy level:
[edit interfaces interface-name interface-type-options]
bert-algorithm algorithm;
bert-error-rate rate;
bert-period seconds;
is the bit error rate. This can be an integer from 0 through 7, which corresponds
–0
is the pattern to send in the bit stream. For a list of supported algorithms,
?
after the
bert-algorithm
pseudo-2e11-o152
Pattern is 2^11 -1 (per O.152 standard)
pseudo-2e15-o151
Pattern is 2^15 - 1 (per O.152 standard)
pseudo-2e20-o151
Pattern is 2^20 - 1 (per O.151 standard)
pseudo-2e20-o153
Pattern is 2^20 - 1 (per O.153 standard)
...
bert-period
[edit interfaces interface-name
–7
(1 error per bit) to 10
(1 error per 10 million bits).
statement; for example:
,
bert-algorithm
, and
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