This variable describes the variety of Zero Code Suppression used on the link, which in turn affects a number of its characteristics. b8zs refers to the use of a specified pattern of normal bits and bipolar violations which are used to replace a sequence of eight zero bits. ami refers to a mode wherein no zero code suppression is present and the line encoding does not solve the problem directly. In this application, the higher layer must provide data which meets or exceeds the pulse density re- quirements, such as inverting HDLC data. E1 links, with or without CRC, use dsx1HDB3 or dsx1AMI.