Value,Name,Description,Reference
0x01,NEW,Initiate a new call,[RFC5457]
0x02,PING,Ping request,[RFC5457]
0x03,PONG,Ping or poke reply,[RFC5457]
0x04,ACK,Explicit acknowledgment,[RFC5457]
0x05,HANGUP,Initiate call tear-down,[RFC5457]
0x06,REJECT,Reject a call,[RFC5457]
0x07,ACCEPT,Accept a call,[RFC5457]
0x08,AUTHREQ,Authentication request,[RFC5457]
0x09,AUTHREP,Authentication reply,[RFC5457]
0x0A,INVAL,Invalid message,[RFC5457]
0x0B,LAGRQ,Lag request,[RFC5457]
0x0C,LAGRP,Lag reply,[RFC5457]
0x0D,REGREQ,Registration request,[RFC5457]
0x0E,REGAUTH,Registration authentication,[RFC5457]
0x0F,REGACK,Registration acknowledgement,[RFC5457]
0x10,REGREJ,Registration reject,[RFC5457]
0x11,REGREL,Registration release,[RFC5457]
0x12,VNAK,Video/Voice retransmit request,[RFC5457]
0x13,DPREQ,Dialplan request,[RFC5457]
0x14,DPREP,Dialplan reply,[RFC5457]
0x15,DIAL,Dial,[RFC5457]
0x16,TXREQ,Transfer request,[RFC5457]
0x17,TXCNT,Transfer connect,[RFC5457]
0x18,TXACC,Transfer accept,[RFC5457]
0x19,TXREADY,Transfer ready,[RFC5457]
0x1A,TXREL,Transfer release,[RFC5457]
0x1B,TXREJ,Transfer reject,[RFC5457]
0x1C,QUELCH,Halt audio/video [media] transmission,[RFC5457]
0x1D,UNQUELCH,Resume audio/video [media] transmission,[RFC5457]
0x1E,POKE,Poke request,[RFC5457]
0x1F,Reserved,Reserved for future use,[RFC5457]
0x20,MWI,Message waiting indication,[RFC5457]
0x21,UNSUPPORT,Unsupported message,[RFC5457]
0x22,TRANSFER,Remote transfer request,[RFC5457]
0x23,Reserved,Reserved for future use,[RFC5457]
0x24,Reserved,Reserved for future use,[RFC5457]
0x25,Reserved,Reserved for future use,[RFC5457]
0x26,TXMEDIA,request a media-only transfer,[Kevin_P._Fleming]
0x27,RTKEY,initiate an encryption key rotation sequence,[Kevin_P._Fleming]
0x28,CALLTOKEN,provide a call token used for 3-way handshake during call setup,[Kevin_P._Fleming]
0x29-0x2F,Unassigned,,
0x30,T38_REQUEST_NEGOTIATE,T38_REQUEST_NEGOTIATE,[Kevin_P._Fleming]
0x31,T38_REQUEST_TERMINATE,T38_REQUEST_TERMINATE,[Kevin_P._Fleming]
0x32,T38_NEGOTIATED,T38_NEGOTIATED,[Kevin_P._Fleming]
0x33,T38_TERMINATED,T38_TERMINATED,[Kevin_P._Fleming]
0x34,T38_REFUSED,T38_REFUSED,[Kevin_P._Fleming]
0x35-0x7F,Unassigned,,