UInt16

UInt16 stores values from 0 through 65_535.

local port: UInt16 = 8_080
local nextPort = port + 1
print(`port={nextPort}`)

Use UInt16 when a protocol or binary representation requires this width. A nonnegative business rule alone is not a reason to replace validation with an unsigned type.

local wide: UInt32 = 65_000
local port = UInt16(wide)

Narrowing is explicit and checked.