C2 Byte And Scrambling - Cisco ONS 15454 SDH Configuration Manual

C2 Byte and Scrambling

To configure path alarms as triggers and specify a delay, perform the following steps beginning in global
configuration mode:
Command
Step 1
Router(config)# interface pos
number
Step 2
Router(config-if)# pos trigger
defect {all | ber_sf_b3 | encap
| pais | plop | ppdi | pplm |
prdi | ptim | puneq}
Step 3
Router(config-if)# pos trigger
delay millisecond
Step 4
Router(config-if)# end
Step 5
Router# copy running-config
startup-config
C2 Byte and Scrambling
One of the overhead bytes in the SONET/SDH frame is the C2 byte. The SONET/SDH standard defines
the C2 byte as the path signal label. The purpose of this byte is to communicate the payload type being
encapsulated by the SONET framing overhead (FOH). The C2 byte functions similarly to EtherType and
Logical Link Control (LLC)/Subnetwork Access Protocol (SNAP) header fields on an Ethernet network;
it allows a single interface to transport multiple payload types simultaneously. The C2 byte is not
configurable.
Table 5-5
Signal Label
0x01
0x05
0xCF
Cisco ONS 15454 and Cisco ONS 15454 SDH Ethernet Card Software Feature and Configuration Guide, R8.0
5-8
Table 5-5 provides C2 byte hex values.
C2 Byte and Scrambling Default Values
SONET/SDH Payload Contents
LEX Encapsulation with 32-bit CRC with or without scrambling
LEX Encapsulation with 16-bit CRC with or without scrambling
Cisco HDLC or PPP/BCP without scrambling
Purpose
Enters interface configuration mode and specifies the POS
interface to configure.
Configures certain path defects as triggers to bring down the
POS interface. The configurable triggers are as follows:
all—All link down alarm failures
•
ber_sd_b3—PBIP BER in excess of SD threshold
•
failure
ber_sf_b3—PBIP BER in excess of SD threshold failure
•
(default)
encap—Path Signal Label Encapsulation Mismatch
•
failure (default)
pais—Path Alarm Indication Signal failure (default)
•
plop—Path Loss of Pointer failure (default)
•
ppdi—Path Payload Defect Indication failure (default)
•
pplm—Payload label mismatch path (default)
•
prdi—Path Remote Defect Indication failure (default)
•
ptim—Path Trace Indicator Mismatch failure (default)
•
puneq—Path Label Equivalent to Zero failure (default)
•
Sets waiting period before the line protocol of the interface
goes down. Delay can be set from 200 to 2000 ms. If no time
intervals are specified, the default delay is set to 200 ms.
Returns to the privileged EXEC mode.
(Optional) Saves configuration changes to NVRAM.
Chapter 5 Configuring POS