Cisco Cisco IOS Software Release 12.0(21)S

To perform a bit error rate test using a specified test pattern on a channelized interface on a Cisco 12000 
series Internet routers, use the bert pattern interval command in global configuration mode. To disable 
BER testing, use the no form of this command.

[t1 line-number] [e1 line-number] bert pattern pattern interval time

no [t1 line-number] bert pattern pattern interval time

No default behavior or values.

Global configuration

You can configure only one BER test on a T3 port. If you start more than one test, the following error 
message is displayed:

%BERT is already running on T1 t1-line-number  T3 port-number.  Only one T1 bert test can 

be running at a time.

The bit error rate test pattern occupies only the T1 or E1 payload bits.

t1 line-number

Optional. Configures a BER test on a T1 line under SONET or SDH framing 
by specifying the line number. Range: 1 to 28.

e1 line-number

Optional. Configures a BER test on an E1 line under SDH framing with 
AU-3 AUG mapping by specifying the line number. Range: 1 to 28.

bert pattern pattern

Specifies the DS1 test pattern to be used in the BER test. Valid values: 0s, 
1s, 2^11, 2^15, 2^20, 2^23, alt-0-1, 1-8, and a user-defined value.

See 

Table 2

 for a description of the patterns that are supported by each 

channelized interface. 

interval time

Specifies the duration of the BER test in minutes. Range: 1 to 14400. 
(14400 minutes is equal to 240 hours.) 

12.0(21)S

This command was introduced.

12.2(28)SB

This command was integrated into Cisco IOS Release 12.2(28)SB.