The line configuration parameter MAXDELAYOCTET-split (MDOSPLIT) defines the percentage of the MAXDELAYOCTET_ext if operating in ITU-T G.998.4 or MAXDELAYOCTET in other cases allocated to the downstream direction. All of the remaining MAXDELAYOCTET or MAXDELAYOCTET_ext shall be allocated for use in the upstream direction. The detailed specification is in ITU-T G.993.2 and ITU-T G.998.4. MDOSPLIT shall be expressed as a percentage, with valid range from 5 percent to 95 percent inclusive, in steps of 1 percent. The value 0% is valid only if the maximum downstream interleaving delay is configured with the special value S1 (see clause 7.3.2.2) and retransmission is disabled in the downstream direction. The value 100% is valid only if the maximum upstream interleaving delay is configured with the special value S1 (see clause 7.3.2.2) and retransmission is disabled in the upstream direction. A special value (255) shall indicate that the VTU-O is allowed to use a vendor discretionary algorithm. NOTE - The special value is introduced to ensure backwards compatibility.