Vezérlõ mezõ formátumok: 8 7 6 5 4 3 2 1 +----------Â---Â-------Â-------+ octet | | | | | U - format 4 |M M M |P/F| M M | 1 1 | unnumbered +----------Á---Á-------Á-------+ számozatlan keret M Modifier function bit P/F Poll bit when issued as a command, final bit when issued as a response +--Â---Â---Â---Â---Â---Â---Â---+ U |0 | 1 | 1 | P | 1 | 1 | 1 | 1 | SABME -set asynchronous balanced +--Á---Á---Á---Á---Á---Á---Á---+ mode 2. layer kapcsolat felépítés kezdeményezés +--Â---Â---Â---Â---Â---Â---Â---+ U |0 | 0 | 0 | F | 1 | 1 | 1 | 1 | DM -disconnected mode +--Á---Á---Á---Á---Á---Á---Á---+ +--Â---Â---Â---Â---Â---Â---Â---+ U |0 | 0 | 0 | P | 0 | 0 | 1 | 1 | UI -unnumbered information +--Á---Á---Á---Á---Á---Á---Á---+ +--Â---Â---Â---Â---Â---Â---Â---+ U |0 | 1 | 0 | P | 0 | 0 | 1 | 1 | DISC -disconnect +--Á---Á---Á---Á---Á---Á---Á---+ 2. layer kapcsolat bontás +--Â---Â---Â---Â---Â---Â---Â---+ U |0 | 1 | 1 | F | 0 | 0 | 1 | 1 | UA -unnumbered acknowledge +--Á---Á---Á---Á---Á---Á---Á---+ +--Â---Â---Â---Â---Â---Â---Â---+ U |1 | 0 | 0 | F | 0 | 1 | 1 | 1 | FRMR -frame reject +--Á---Á---Á---Á---Á---Á---Á---+ +--Â---Â---Â---Â---Â---Â---Â---+ U |1 | 0 | 1 |P/F| 1 | 1 | 1 | 1 | XID -exchange identification +--Á---Á---Á---Á---Á---Á---Á---+ UA - üzemmódbeállító parancs (SABME,DISC) nyugtázása: UI - információtovábbítás (nem checkelt)