8. A method comprising: receiving, from an optical receiver and by a device, a word, of a block of words within traffic, on which to perform forward error correction, each word of the block of words including respective encoded bits and respective sets of reliability bits for identifying a respective level of reliability of each one of the respective encoded bits; identifying, by the device, least reliable positions, within the word, that correspond to a subset of encoded bits, within the word, associated with one or more lowest levels of reliability; generating, by the device, a set of candidate words based on different combinations in which the subset of encoded bits can be inverted; identifying, by the device, a first pair of candidate words, within the set of candidate words, the first pair including a first word and a second word, the first word including a first bit, the first bit not being an inverted bit and being most reliable within the subset of encoded bits associated with the first word; identifying, by the device, a first quantity of errors associated with the first word and a second quantity of errors associated with the second word; determining, by the device, whether the first quantity of errors is greater than the second quantity of errors; selecting, by the device, the first word when the first quantity of errors is not greater than the second quantity of errors; identifying, by the device, a second pair of candidate words, within selected words of the set of candidate words, the second pair including the first word and a third word, the third word including a second bit that is most reliable within the subset of encoded bits associated with the third word; determining, by the device, whether the second bit is an inverted bit; selecting, by the device, the first word when the second bit is an inverted bit; and performing, by the device, forward error correction on the word based on the selected first word.
8. A method comprising: receiving, from an optical receiver and by a device, a word, of a block of words within traffic, on which to perform forward error correction, each word of the block of words including respective encoded bits and respective sets of reliability bits for identifying a respective level of reliability of each one of the respective encoded bits; identifying, by the device, least reliable positions, within the word, that correspond to a subset of encoded bits, within the word, associated with one or more lowest levels of reliability; generating, by the device, a set of candidate words based on different combinations in which the subset of encoded bits can be inverted; identifying, by the device, a first pair of candidate words, within the set of candidate words, the first pair including a first word and a second word, the first word including a first bit, the first bit not being an inverted bit and being most reliable within the subset of encoded bits associated with the first word; identifying, by the device, a first quantity of errors associated with the first word and a second quantity of errors associated with the second word; determining, by the device, whether the first quantity of errors is greater than the second quantity of errors; selecting, by the device, the first word when the first quantity of errors is not greater than the second quantity of errors; identifying, by the device, a second pair of candidate words, within selected words of the set of candidate words, the second pair including the first word and a third word, the third word including a second bit that is most reliable within the subset of encoded bits associated with the third word; determining, by the device, whether the second bit is an inverted bit; selecting, by the device, the first word when the second bit is an inverted bit; and performing, by the device, forward error correction on the word based on the selected first word. 9. The method of claim 8 , where the second word includes a first bit that does not match a second bit, within the first word, to which the first bit corresponds, the first bit corresponding to one of the least reliable positions.