ECMA-72

This ECMA Standard specifies

i) five classes of procedures

Class 0 : Simple class,
Class 1 : Basic error recovery class,
Class 2 : Multiplexing class,
Class 3 : Error recovery and multiplexing class,
Class 4 : Error detection and recovery class,

for the connection-oriented transfer of data and control information from one transport entity to a peer transport entity;

ii) the means of negotiating the class of procedures to be used by the transport entities;

iii) the structure and encoding of the transport protocol data units used for the transfer of data and control information.