Configure BERT Properties

You can configure any of the following interfaces to execute a bit error rate test (BERT) when the interface receives a request to run this test: E1, E3, T1, T3, the original Channelized DS-3, OC-3, OC-12, and STM-1 interfaces, and the Channelized DS-3, E1, and OC-12 QPP interfaces. On all of the specified interface types, you set the duration of the test and the error rate to include in the bit stream by including the bert-period and bert-error-rate statements at the [edit interfaces interface-name interface-options] hierarchy level:

[edit interfaces interface-name interface-options]

bert-error-rate rate; 

bert-period seconds; 

seconds is the duration of the BERT procedure, in seconds. The test can last from 1 to 240 seconds; the default is 10 seconds.

rate is the bit error rate. This can be an integer in the range 0 through 7, which corresponds to a bit error rate in the range 10^-0 (that is, 1 error per bit) to 10^-7 (that is, 1 error per 10 million bits).

algorithm is the pattern to send in the bit stream. The algorithm for the E1 BERT procedure is pseudo-2e15-o151 (pattern is 2¹⁵-1, as defined in the CCITT/ITU O.151 standard). On T1, E3, T3, NxDS-0, and Channelized E1 and T3 QPP interfaces, you can also select the pattern to send in the bit stream by including the bert-algorithm statement at the [edit interfaces interface-name interface-options] hierarchy level:

[edit interfaces interface-name interface-options]

bert-algorithm algorithm; 

For a list of supported algorithms, see the CLI possible completions; for example:

[edit interfaces t1-0/0/0 t1-options]

user@host# set bert-algorithm ?

Possible completions:

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)

...

See individual interface types for specific hierarchy information. For information about running the BERT procedure, see the JUNOS Internet Software Operational Mode Command Reference.

Table 9 shows the BERT capabilities for various interface types.

Table 9: BERT Capabilities by Interface Type

Interface	T1 BERT	T3 BERT	Comments
E1 or T1	Yes (port 0-3)	Yes (port 0-3)	Single port at a time Limited algorithms
E3 or T3	Yes (port 0-3)	Yes (port 0-3)	Single port at a time
Original Channelized OC-12	N/A	Yes (channel 0-11)	Single channel at a time Limited algorithms No bit count
Channelized STM-1	Yes (channel 0-62)	N/A	Multiple channels Only one algorithm No error insert No bit count
Original Channelized T3 and Multichannel T3	Yes (channel 0-27)	Yes (port 0-3 on channel 0)	Multiple ports and channels Limited algorithms for T1 No error insert for T1 No bit count for T1

For information about BERT capabilities on channelized QPP interfaces, see Channelized QPP Interface Properties.