This sets the DS1 line coding scheme: B8ZS, which replaces runs of eight zero bits with a specific bit pattern containing intentional bipolar violations to maintain pulse density, or AMI, which provides no such substitution and instead relies on the connected equipment to guarantee sufficient ones density, for example by inverting HDLC data. An admin must match this setting to whatever the far-end DS1 equipment expects, since a coding mismatch will cause the receiving side to misinterpret the bit stream. Most modern DS1 circuits use B8ZS, with AMI reserved for older or specific legacy equipment.