Methods and apparatus for detecting alignment markers in received data streams received via a plurality of data lanes are disclosed. Corresponding data streams may be received via respective data lanes in the plurality of data lanes, where each data stream includes alignment markers delineating data frames, and each alignment marker has a predefined bit pattern. For each respective data lane, a determination is made whether a specified portion of the received data stream has at least a threshold degree of similarity with a portion of the predefined bit pattern. In response to determining, for one of the plurality of data lanes, that the specified portion has at least the threshold degree of similarity, a frame boundary may be determined based on the specified portion, and a verification may be performed, that the specified portion of the received data stream corresponds to an alignment marker.