Description: This attribute indicates the current mode of the V.42bis decoder. This mode can be either: transparent - A mode of operation in which compression has been selected but data is being transmitted in uncompressed form. Transparent mode command sequences may be inserted into the data stream. compressed - A mode of operation in which data is transmitted in codewords. The encoder (at the mobile or Public Switched Telephone Network) switches between the two modes depending on whether the data coming from the Date Terminal Equipment (DTE) is suitable for compression. The data comression function periodically determines the compressibility of the data based on a comparison of the number of bits required to represent a segment of the data stream before and after compression.