The encoding law used is the µ-law as specified in Recommendation G.711. The sampling rate, load capacity and the code are also specified in that Recommendation. The number of quantized values is 255. Two character signals are reserved for zero value (11111111 and 01111111). In some networks the all-0 character signal (00000000) is eliminated to avoid loss of timing information to the digital line, resulting in 254 quantized values.