This read-only CoriantTypesEnableSwitch value reports whether GFP payload FCS is used on this 40 Gigabit Ethernet (40GbE) client port, defaulting to disabled. When enabled, the GFP payload's own frame check sequence is used and the original Ethernet frame FCS is removed; when disabled, the Ethernet FCS is kept intact and no separate GFP FCS is inserted, which affects how downstream equipment validates frame integrity. For example, an operator troubleshooting an unexpected framing-integrity alarm on client port 1 would want to know whether this reads enabled or disabled, since that changes which FCS field the equipment is actually supposed to be validating against.