FEC configuration on SonicWall NSa 6700 and NSsp 10700,11700,13700

SonicWall began supporting 25G/40/100G speeds starting from Gen7  NSa 6700 (and above) class of products . At the moment, UI does not offer explicitly configuring FEC parameters. Instead, we follow generally accepted 802.3 standard recommendations of FEC usage. Type of the FEC is chosen automatically based on the type of the SFP module plugged into the system:

1. For 100G TwinAx and Optical QSFP28 modules, FEC configuration used in RS-FEC (a.k.a Reed Solomon) part of the Clause 91 adaptation:
   1. For 100G TwinAx, FEC configured as RS-FEC (Auto negotiation and Forced speed)
   2. For 100G Optical (SR and LR), FEC configured as RS-FEC. (Forced speed)
2. For 25G TwinAx and Optical SFP28 modules, the FEC configuration used is dependent on the type of modules connected:
   
   1. For 25G TwinAx CA-25G-L, FEC configured as RS-FEC (Auto negotiation and Forced speed) *
   2. For 25G TwinAx CA-25G-S, FEC configured as RS-FEC or BASE-R FEC (BASE-R is also known as Clause 74 or Fire Code) (Auto negotiation). *
   3. For 25G TwinAx CA-25G-N, FEC configured as RS-FEC, BASE-R FEC, or no FEC (Auto negotiation) *
   4. For 25G Optical SR, FEC configured as BASE-R FEC (Forced speed only).
   5. For 25G Optical LR, no FEC (Forced speed only).
   6. Warning : SNWL sfp28 ports does not support Clause 108 FEC which was ratified part of the IEEE 802.3by standard. Sonicwall only supports Clause 91 and Clause 74 FEC (see configuration above). Some of the switches by default use Clause 108 FEC for 25G ports. In such cases user shall configure peer switch to use Clause 91 or Clause 74 depends on SFP according to table below.

NSA Products (Nsa6700 and Nssp 10700, 11700, 13700) and Third Party Switch Configurations for 25G Speed : 

For links to come up properly, peer switch configuration should be in-line with the configuration on NSsp side. Since not all vendors support automatic/default configurations as we do, below is an example of the configuration for various switch vendors for different SFP/QSFP types: