Hi guys!!
I would like to share with you an issue about "Configuring DCC Transparent Transmission for Hybrid Network" on the OptiX equipment (in this case OptiX OSN 1500B).
Description:
In general, the transmission equipment uses only bytes D1 to D3 as DCCs and does not use other DCC bytes. Based on this feature, the DCC transparent transmission solution adopts different DCCs to transmit the NM messages of different vendors to achieve the communication between NM messages.
When DCC bytes are used to transparently transmit NM messages, there are two networking scenarios:
The OptiX equipment is at the edge of a network.
The OptiX equipment is in the center of a network.
In this case, the OptiX equipment is in the center of a network. Therefore, the third-party equipment uses bytes D4 to D12 as DCCs (the OptiX equipment uses bytes D1 to D3 as DCCs and, in addition, you need to add route to transparently transmit bytes D4 to D12).
The OptiX equipment realizes the transparent transmission of DCC through the overhead cross-connect matrix.
In the receive direction:
The line board extracts the overhead bytes such as DCC bytes from the received SDH signals, forms a 2.048 Mbit/s overhead signal stream, and sends the overhead signal stream to the overhead cross-connect matrix of the SCC board through the overhead bus.
The overhead cross-connect matrix transports the DCC bytes that the NE uses to the CPU and directly transports the DCC bytes that are to be transparently transmitted, to the overhead bus of the corresponding line board.
The CPU processes the NM messages carried by the DCC bytes according to the protocol stack of the DCCs.
In the transmit direction:
The CPU of the SCC board encapsulates the NM messages into the DCC bytes according to the protocol stack and transmits the DCC bytes to the overhead cross-connect matrix of the SCC board.
The overhead cross-connect matrix combines the DCC bytes sent from the CPU and other overhead bytes (including the DCC bytes sent from the other line boards and orderwire bytes) to form a 2.048 Mbit/s overhead signal stream, and then transmits the overhead signal stream to the corresponding line board.
The line board extracts the overhead signal from the overhead signal stream, inserts the overhead signal into the SDH signal, and sends the SDH signal to other NEs.
For more information visit HedEx: OptiX OSN 1500 Product Documentation : Feature Description > Outband DCN > Hybrid Networking Solution of DCC Transparent Transmission
The customer needs configure D4 to D12 channels as transparent on menu: NE Explorer > DCC Management > DCC Transparent Transmission Management , that is:
D1 to D3 with protocol type configured as HWECC
D4 to D12 without protocol type configured (transparent transmission)
but they receive the error: "OHP byte collided: error 38978" (OHP: overhead proccesing).
The configuration can't be done because D4 to D12 channels was configured as IP in the line board ports.
After disable D4 to D12 channels on menu: NE Explorer > DCC Management > DCC Rate Configuration, customer needed delete DCC channels (from D4 to D12) in DCC Rate Configuration, but U2000 displayed the following error:
Solution:
Step 1
Huawei TAC informed us that to delete D4-D12 channels, autonegotiation bandwidth switch had to be closed. But as this option was not available in U2000. This option was closed using next command in Navigator:
In this case, the commands executed to close the line board fiber port negotiate state are:
R2SLN (Slot 4)
:cm-set-cnegoswitch:4,255,1,close
R2SLN (Slot 5)
:cm-set-cnegoswitch:5,255,1,close
Step 2
Disable D4 to D12 channels in the line board fiber port:
Step 3
Delete D4 to D12 channels in the line board fiber port.
Step 4
Configuration D4 to D12 channels of transparent mode on menu: NE Explorer > DCC Management > DCC Transparent Transmission Management > New and the system displays the Create DCC Transparent Transmission Byte dialog box.
Step 5
Open again the line board fiber port negotiate state:
R2SLN (Slot 4)
:cm-set-cnegoswitch:4,255,1,open
R2SLN (Slot 5)
:cm-set-cnegoswitch:5,255,1,open
Step 6
Click Query on menu: NE Explorer > DCC Management > DCC Rate Configuration. Then D4 to D12 channels in transparent transmission mode (without protocol type) appears again.
Issue solved.
BR
!! 
