Specifying The Atm Alarm Thresholds; Controlling The S1 Sonet Overhead Byte - Cisco 10000 Series Configuration Manual

ATM Commands

Specifying the ATM Alarm Thresholds

Specify the bit error rate (BER) threshold by using the atm threshold command:
atm threshold {b1-tca | b2-tca | b3-tca | sd-ber | sf-ber} value
Where:
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The default for all thresholds, except sf-ber, is 10
The following example shows how to specify the B1 BER threshold crossing alarm value of 4:
Router(config)# interface atm 5/0/0
Router(config-if)# atm threshold b1-tca 4

Controlling the S1 SONET Overhead Byte

On Cisco 10000 series routers, ATM line cards run over SONET. In most situations, the default value for
the S1 SONET overhead byte (0x0) does not need to be changed. Refer to the SONET standards for
information about the possible values for the S1 SONET overhead byte and the definition of each value.
Controlling a Transmitted S1 Overhead Byte
In Cisco IOS Release 12.2(28)SB, use the pos flag s1-byte tx command in interface configuration mode
to control the transmission of the S1 SONET overhead byte.
pos flag s1-byte tx value
Where:
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In the following example the S1 SONET overhead byte is set to 0xF:
pos flag s1-byte tx 0xF
Reacting to a Received S1 Overhead Byte
In Cisco IOS Release 12.2(28)SB, use the pos flag s1-byte rx-communicate command to direct the
router to switch the clock source to internal when it receives an S1 SONET overhead byte with a value
of 0xF. When the S1 SONET overhead byte changes from 0xF to any other value, the clock source reverts
back to the clock source specified in the user configuration.
The S1 overhead byte is ignored by the receiving router unless the pos flag s1-byte rx-communicate
command is issued.
pos flag s1-byte rx-communicate
no pos flag s1-byte rx-communicate
Cisco 10000 Series Router Line Card Configuaration Guide
1-14
b1-tca—B1 BER threshold crossing alarm
b2-tca—B2 BER threshold crossing alarm
b3-tca—B3 BER threshold crossing alarm
sd-ber—Set Signal Degrade BER threshold
sf-ber—Set Signal Fail BER threshold
value is an exponential value from 10
value is in the range of 0x0 to 0xF
0x0 is the default value
Chapter 1 4-Port OC-3/STM-1 ATM Line Card Configuration
–3 –9
to 10 representing the BER at which an alarm occurs.
-6
. The default for sf-ber is 10
-3
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