Bit-transparent muxing of an input signal for transport through an optical communications network is provided. A fixed length container of the optical communications network is defined, which includes an overhead and a payload. A stuffing ratio (α) is based on a line rate of the input signal and a data rate of the container. A number (NFS) of fixed stuffs is computed based on the stuffing ratio (α). The input signal and NFS fixed stuffs are inserted into the payload of the container, and the computed number NFS stored in the container's overhead.