Path Signal Label, C2 Byte; Table 11-9 Ons 15454 Cards Capable Of J1 Path Trace - Cisco 15454-DS1-14= - 1.544Mbps Expansion Module Reference Manual

Chapter 11 Circuits and Tunnels
Table 11-9
J1 Function
Transmit and Receive
Receive Only
1. J1 path trace is not supported for DS-1s used in VT circuits.
If the string received at a circuit drop port does not match the string the port expects to receive, an alarm
is raised. Two path trace modes are available:
•
•

11.14 Path Signal Label, C2 Byte

One of the overhead bytes in the SONET frame is the C2 byte. The SONET 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 STS path overhead (POH). The C2 byte functions similarly to EtherType and Logical Link Control
78-18106-01
ONS 15454 Cards Capable of J1 Path Trace
Cards
CE-Series
DS1-14
DS1N-14
DS1/EC1-56
DS3-12E
DS3i-N-12
DS3/EC1-48
DS3N-12E
DS3XM-6
DS3XM-12
FC_MR-4
G-Series
ML-Series
EC1-12
OC3 IR 4/STM1 SH 1310
OC3 IR 4/STM1 SH 1310-8
OC12/STM4-4
OC48 IR/STM16 SH AS 1310
OC48 LR/STM16 LH AS 1550
OC192 SR/STM64 IO 1310
OC192 LR/STM64 LH 1550
OC192 IR/STM SH 1550
OC192-XFP
Automatic—The receiving port assumes that the first string it receives is the baseline string.
Manual—The receiving port uses a string that you manually enter as the baseline string.
1
Cisco ONS 15454 Reference Manual, R8.5
11.14 Path Signal Label, C2 Byte
11-25