Methods and apparatus for controlling transmission of data units in a network. In one embodiment, a method of controlling transmission of data units in a network node includes receiving a fragment of a data unit. The method further includes determining at least one of (a) whether a prior fragment of the data unit has been dropped and (b) whether a subsequent fragment of the data unit is likely to be dropped. The method further includes at least one of (c) transmitting the received fragment of the data unit only if no prior data fragment of the data unit has been dropped and (d) transmitting the fragment of the data unit only if no subsequent fragment of the data unit is likely to be dropped.