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Forward Error Correction (FEC) Types

 

Forward error correction can be provisioned on OTU and optical channel interfaces. The following are the supported configurations:

Table 1: FEC Types

Interface

Supported FEC Types

OTU2 or OTU2e

  • No FEC (no-fec)

  • Generic FEC (g-fec)

  • G.975.1 i.4 Super FEC (s-fec-i4)

  • G.975.1 i.7 Super FEC (s-fec-i7)

Note: The ports on the 12x SFP+ BIC are divided into three port groups (ports 1 to 4, ports 5 to 8, ports 9 to 12). Within each port group, you cannot configure one port for G.975.1 i.4 Super FEC and another port for G.975.1 i.7 Super FEC. The Super FEC settings are mutually exclusive within a port group.

On a UFM6, all 10-Gbps client ports within the same QSFP+ transceiver have a similar restriction. You cannot configure one 10-Gbps port for G.975.1 i.4 Super FEC and another 10-Gbps port on the same transceiver for G.975.1 i.7 Super FEC. The Super FEC settings are mutually exclusive within a transceiver.

OTU4 on 100G Coherent MSA XCVR

  • Soft-Decision FEC (soft-fec)

OTU4 on 100G Coherent CFP

  • Soft-Decision FEC (soft-fec)

OTU4 on all other CFPs

  • Swizzle FEC (swiz-fec)

OTU4 on the QSFP28 100GE Ethernet/OTN LR4 (QSFP-100G-LR4-D (740-073859))

  • No FEC (no-fec)

  • Generic FEC (g-fec)

Optical channel on 400G Coherent MSA XCVR

  • Soft-Decision FEC with 25% overhead (sd-fec-25pc) for 16-QAM modulation

  • Soft-Decision FEC with 25% overhead (sd-fec-25pc) for QPSK modulation - Releases 4.2 and higher

  • Soft-Decision FEC (soft-fec) for QPSK modulation - Releases 4.2 and higher

Note: This FEC is applied to the optical channel, which can include one or two OTU4 signals.

Release History Table
Release
Description
OTU4 on the QSFP28 100GE Ethernet/OTN LR4 (QSFP-100G-LR4-D (740-073859))
Soft-Decision FEC with 25% overhead (sd-fec-25pc) for QPSK modulation
Soft-Decision FEC (soft-fec) for QPSK modulation