VC4 Path Overhead

Normally, the default values of the overhead bytes to be received or transmitted are adopted to meet the relevant requirements. You should configure the J1 byte or C2 byte in the VC4 path overheads (POHs) when the HP_TIM or HP_SLM alarm is reported on the line board at the local or remote NE. You can query and set overhead bytes of the VC4 path in this user interface.

Navigation Path

In the NE Explorer, click the board and select Configuration > Overhead Management > VC4 Path Overhead from the Function Tree.

Radio Buttons

Radio button	Description
Display in Text Format	Enables the text format display of overhead bytes.
Display in Hexadecimal	Enables the hexadecimal display of overhead bytes.

Parameters

**Table 1** Descriptions of the parameters for VC4 Path Overhead
Field	Value	Description
Object	Equipment that supports the master and slave shelf management: NE name-shelf ID(shelf name)-slot number-board name-port number(port name) Equipment that does not support the master and slave shelf management: NE name-slot number-board name-port number(port name)	Displays the name of the operation object.
J1 to be Sent ([Mode] Content)	For example: [16 Bytes]HuaWei SBS	Sets the higher-order path overhead byte J1 to be sent. [Mode] indicates whether the overhead byte is of the single-byte mode, 16-byte mode or 64-byte mode. It is applicable to SDH line boards. The default value is usually used, but in the case of Huawei equipment interconnecting with third-party equipment, you need to set the same value as J1 to be received at the opposite end.
J1 to be Received ([Mode] Content)	For example: [16 Bytes]HuaWei SBS	Sets the higher-order path overhead byte J1 to be received. [Mode] indicates whether the overhead byte is of the single-byte mode, 16-byte mode, 64-byte mode or diable mode. It is applicable to SDH line boards. The default value is usually used, but in the case of Huawei equipment interconnecting with third-party equipment, you need to set the same value as J1 to be sent of the opposite end. When this parameter is set to Disable Mode, the board does not detect the received J1 byte.
J1 Received ([Mode] Content)	/	Queries the higher-order path overhead byte J1 received. The NE reports an alarm if the byte is different from the J1 to be received. [Mode] indicates whether the overhead byte is of the single-byte mode, 16-byte mode or 64-byte mode.
C2 to be Sent	(0x00)Unequipped, (0x01)Reserved, (0x02)TUG Structure, (0x03)Locke TU-n, (0x04)34M/45M into C-3, (0x05)Experimental, (0x12)140M into C-4 asynchronously, (0x13)ATM Mapping, (0x14)MAN DQDB Mapping, (0x15)FDDI Mapping, (0x16)HDLC/PPP Mapping, (0x17)Reserved for Special Purpose, (0x18)HDLC/LAPS Mapping, (0x19)Reserved for Special Purpose, (0x1A)10G Ethernet Frame, (0x1B)GFP Mapping, (0xCF)Reserved, (0xFC)Reserved2, (0xFE)O.181 Test Signal, (0xFF)VC-AIS	Sets the signal label byte C2 to be sent. It is applicable to SDH line boards. The default value is usually used, but when accessing signals of non-TUG structure (for example, ATM, FDDI), you need to set the C2 to be sent as required. If the remote NE reports the HP_SLM alarm, set this parameter according to the C2 byte to be received at the remote NE.
C2 to be Received	(0x00)Unequipped, (0x01)Reserved, (0x02)TUG Structure, (0x03)Locke TU-n, (0x04)34M/45M into C-3, (0x05)Experimental, (0x12)140M into C-4 asynchronously, (0x13)ATM Mapping, (0x14)MAN DQDB Mapping, (0x15)FDDI Mapping, (0x16)HDLC/PPP Mapping, (0x17)Reserved for Special Purpose, (0x18)HDLC/LAPS Mapping, (0x19)Reserved for Special Purpose, (0x1A)10G Ethernet Frame, (0x1B)GFP Mapping, (0xCF)Reserved, (0xFC)Reserved2, (0xFE)O.181 Test Signal, (0xFF)VC-AIS	Sets the signal label byte C2 to be received. It is applicable to the SDH line board. The default is usually used, but when accessing signals of non-TUG structure (for example, ATM, FDDI), you need to set the C2 to be received as required. If the local NE reports the HP_SLM alarm, set this parameter according to the C2 byte to be transmitted from the remote NE.
C2 Received	For example: (0x00)Unequipped	Queries the signal label byte C2 received. Reports an alarm if it is different from the C2 to be received.
VC4 Overhead Termination	Auto, Termination, Pass-Through	Displays VC4 overhead termination. When this parameter is set to Pass-Through, the local NE detects the VC4 overheads (the C2 byte is not detected) and then forwards the original overheads. When this parameter is set to Termination, the local NE detects the VC4 overheads (the C2 byte is not detected) and then generates new VC4 overheads according to the board settings. When this parameter is set to Auto, the VC4 overhead termination of VC4 pass-through services is Pass-Through and the overhead termination of the VC3/VC12 services is Termination. It is recommended that this parameter takes the default value.
Input in Text Format	For example: HuaWei SBS	Enters the overhead bytes. When setting overhead bytes in text mode, use only ASCII characters.
Byte Mode	Single byte, 16-byte (first byte created automatically), 64-Byte Mode (Synchronization Bit 0x0D,0x0A), 64-byte (without synchronization bit), Disable Mode	Sets byte mode for the overhead byte.