Glossary

PER (Packed Encoding Rules) is an encoding specification for ASN.1 definitions. It is defined in ITU-T X.691 standard.

PER is optimized for size, where ASN.1 messages gets encoded into a relatively small size when sent over the network. For example, a boolean field in PER will get encoded using a single bit.

PER has two ways of encoding messages - an aligned form and a non-aligned form. The aligned form takes into consideration that messages are encoded by machines that better perform when data is aligned into 8-bit chunks (byte sizes).