Distinguishing between 100G hard decision and soft decision NS4 boards

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The hard decision of a short-distance transmission board covers all OTM sites on a ring.
Compared with a hard decision board, a soft decision board has higher decision margin, supports longer transmission distance, and tolerates a higher BER.
How can I identify 100G hard decision and soft decision NS4 boards?
1. BOM: 03030SSE, finished board, Optix OSN 8800-TN57NS4T01, 100 Gbit/s line service processing board, (LH, HFEC, Coherent, Tunable, 50 GHz, LC)
//Boards containing HFEC are hard decision boards.
03030YUB finished board, Optix OSN 8800-TN57NS4T61, 100 Gbit/s line board (ULH, SDFEC2, wDCM, Coherent, Tunable, 50 GHz, LC)
// Boards containing SDFEC2 are soft decision boards that support longer transmission distance and tolerate higher BERs.
2. NMS:
On the U2000, click an NS4 board for WDM query. If a board contains HFEC, it is a hard decision board. If a board contains SDFEC2, it is a soft decision board.
In a DWDM system, because of various factors, some bit errors (the ratio of bit errors to the received bits is called bit error ratio or BER) are generated at the receive end after the O/E conversion. As a result, the electrical signal recovered by the receiver is not satisfactory. FEC was therefore introduced to DWDM systems. To correct bit errors, an FEC encoder is used at the transmit end and an FEC decoder is used at the receive end. This helps reduce the BER at the receive end.
Extra overhead is introduced when the FEC encoder/decoder encodes/decodes the raw data. The percentage of the FEC overhead to the raw data is called FEC overhead percentage.
The FEC type used by hard-decision boards is HD-FEC, and the FEC overhead percentage is 7%. The HD-FEC decoder receives with only one bit (1 or 0) of information and no other additional information. Therefore, its output is quantized to two levels, namely �?�?and �?�?
The FEC type used by soft-decision boards is SD-FEC, and the FEC overhead percentage is 20%. Different from the HD-FEC decoder, the SD-FEC decoder receives additional data to indicate the reliability of a decision. Samples are classified as a "strong 0", a "weak 0", a "weak 1", and a "strong 1".
The difference between HD-FEC and SD-FEC lies in the data sent to the decoder. As the FEC overhead percentage increasing, the coding gain increases more slowly. As the FEC overhead percentage increasing, SD-FEC will see smaller increases in its NCG compared to HD-FEC, and even no increase in the NCG.
Compared with hard-decision boards, soft-decision boards have larger decision thresholds, support longer transmission distances, and tolerate higher BERs.

Other related questions:
What is the difference between the soft quota and the hard quota supported by the N8000?
When the size of files exceeds the soft quota, users have another seven days to perform write operations. When the size of files exceeds the hard quota, the system inhibits write operations immediately.

What is the difference between the soft quota and the hard quota supported by the file engine?
When the size of files exceeds the soft quota, users have another seven days to perform write operations. When the size of files exceeds the hard quota, the system inhibits write operations immediately.

Whether the OSN 8800 supports 100G boards
Yes, the OSN 8800 supports 100G boards such as LSC and LTX.

Differences between IPSG and DAI of S series switches
For S series switches, both IP Source Guard (IPSG) and Dynamic ARP Inspection (DAI) use binding tables (static binding table or DHCP snooping binding table) to filter packets. �?IPSG filters IP packets by using binding tables. A switch matches IP packets received by interfaces against binding entries, and forwards the packets matching the binding entries. - DAI filters ARP packets by using binding tables. A switch matches ARP packets received by interfaces against binding entries, and forwards the ARP packets matching the binding entries. - IPSG prevents IP address spoofing attacks. For example, a malicious host steals an authorized host's IP address to access the network or initiate attacks. - DAI can prevent man-in-the-middle attacks. Man-in-the-middle attacks are generally initiated through ARP spoofing. That is, the attacker leads traffic to itself to intercept other hosts' information. - IPSG cannot prevent address conflicts. For example, when a malicious host steals an online host's IP address, the ARP request packets sent by the malicious host will be sent to the online host through broadcast, causing an address conflict. To prevent IP address conflicts, you can configure both IPSG and DAI. - IPSG and DAI resolve different issues and meet different requirements. To ensure network security, you can configure both of them.

Whether G.652 fibers can be used for NS4 boards
G.652 fibers can be used if the door of the cabinet housing the NS4 boards can be properly closed.

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