Internet Assigned Numbers Authority audio/telephone-event Parameters Last Updated 2011-12-07 Available Formats [IMG] XML [IMG] HTML [IMG] Plain text Registry included below * Event Code Registry Event Code Registry Registration Procedure(s) Specification Required Expert(s) Unassigned Reference [RFC4733] Available Formats [IMG] CSV Event Code Event Name Reference 0 DTMF digit "0" [RFC4733] 1 DTMF digit "1" [RFC4733] 2 DTMF digit "2" [RFC4733] 3 DTMF digit "3" [RFC4733] 4 DTMF digit "4" [RFC4733] 5 DTMF digit "5" [RFC4733] 6 DTMF digit "6" [RFC4733] 7 DTMF digit "7" [RFC4733] 8 DTMF digit "8" [RFC4733] 9 DTMF digit "9" [RFC4733] 10 DTMF digit "*" [RFC4733] 11 DTMF digit "#" [RFC4733] 12 DTMF digit "A" [RFC4733] 13 DTMF digit "B" [RFC4733] 14 DTMF digit "C" [RFC4733] 15 DTMF digit "D" [RFC4733] 16 Reserved 17-22 Unassigned 23 CRdSeg: second segment of V.8 bis CRd signal [RFC4734] 24 CReSeg: second segment of V.8 bis CRe signal [RFC4734] 25 MRdSeg: second segment of V.8 bis MRd signal [RFC4734] 26 MReSeg: second segment of V.8 bis MRe signal [RFC4734] 27 V32AC: A pattern of bits modulated at 4800 bits/s, emitted by a V.32/V.32bis answering terminal upon detection of the AA [RFC4734] pattern. 28 V8bISeg: first segment of initiating V.8 bis signal [RFC4734] 29 V8bRSeg: first segment of responding V.8 bis signal [RFC4734] 30 V21L300: 300 bits/s low channel V.21 indication [RFC4734] 31 V21H300: 300 bits/s high channel V.21 indication [RFC4734] 32 ANS (V.25 Answer tone). Also known as CED (T.30 Called tone). [RFC4734] 33 /ANS (V.25 Answer tone after phase shift). Also known as /CED (T.30 Called tone after phase shift) [RFC4734] 34 ANSam (V.8 amplitude modified Answer tone) [RFC4734] 35 /ANSam (V.8 amplitude modified Answer tone after phase shift) [RFC4734] 36 CNG (T.30 Calling tone) [RFC4734] 37 V.21 channel 1 (low channel), '0' bit [RFC4734] 38 V.21 channel 1, '1' bit. Also used for ESiSeg (second segment of V.8 bis ESi signal). [RFC4734] 39 V.21 channel 2, '0' bit [RFC4734] 40 V.21 channel 2, '1' bit. Also used for ESrSeg (second segment of V.8 bis ESr signal). [RFC4734] 41-48 Reserved 49 CT (V.25 Calling Tone) [RFC4734] 50-51 Unassigned 52 ANS2225: 2225 Hz indication for text telephony [RFC4734] 53 CI (V.8 Call Indicator signal preamble) [RFC4734] 54 V.21 preamble flag (T.30) [RFC4734] 55 V21L110: 110 bits/s V.21 indication for text telephony [RFC4734] 56 B103L300: Bell 103 low channel indication for text telephony [RFC4734] 57 V23Main: V.23 main channel indication for text telephony [RFC4734] 58 V23Back: V.23 back channel indication for text telephony [RFC4734] 59 Baud4545: 45.45 bits/s Baudot indication for text telephony [RFC4734] 60 Baud50: 50 bits/s Baudot indication for text telephony [RFC4734] 61 VBDGen: Tone patterns indicative of use of an unidentified modem type [RFC4734] 62 XCIMark: A pattern of bits modulated in the V.23 main channel, emitted by a V.18 calling terminal. [RFC4734] 63 V32AA: A pattern of bits modulated at 4800 bits/s, emitted by a V.32/V.23bis calling terminal. [RFC4734] 64-88 Reserved 90-95 Unassigned 96-112 Reserved 113-114 Unassigned 115 North American SIT Segment 1 Low [GR-674] 116 North American SIT Segment 1 High [GR-674] 117 North American SIT Segment 2 Low [GR-674] 118 North American SIT Segment 2 High [GR-674] 119 North American SIT Segment 3 [GR-674] 120 North American Coin Deposit [GR-506] 121 Continuity check-tone [RFC5244] 122 Continuity verify-tone [RFC5244] 123 MF Code 11 (SS No. 5) or KP3P/ST3P (R1) [RFC5244] " North American Ringback [GR-506] 124 MF KP (SS No. 5) or KP1 (R1) [RFC5244] " North American Coin Return [GR-506] 125 MF KP2 (SS No. 5) or KP2P/ST2P (R1) [RFC5244] 126 MF ST (SS No. 5 and R1) [RFC5244] " North American Coin Collect / Operator Released [GR-506] 127 MF Code 12 (SS No. 5) or KP'/STP (R1) [RFC5244] 128 SS No. 5 or R1 digit "0" [RFC5244] " North American Operator Attached [GR-506] 129 SS No. 5 or R1 digit "1" [RFC5244] 130 SS No. 5 or R1 digit "2" [RFC5244] " North American Coin Collect [GR-506] 131 SS No. 5 or R1 digit "3" [RFC5244] 132 SS No. 5 or R1 digit "4" [RFC5244] 133 SS No. 5 or R1 digit "5" [RFC5244] 134 SS No. 5 or R1 digit "6" [RFC5244] 135 SS No. 5 or R1 digit "7" [RFC5244] 136 SS No. 5 or R1 digit "8" [RFC5244] " North American Operator Released [GR-506] 137 SS No. 5 or R1 digit "9" [RFC5244] 138-143 Reserved 144 ABCD signalling state '0000' [RFC5244] 145 ABCD signalling state '0001' [RFC5244] 146 ABCD signalling state '0010' [RFC5244] 147 ABCD signalling state '0011' [RFC5244] 148 ABCD signalling state '0100' [RFC5244] 149 ABCD signalling state '0101' [RFC5244] 150 ABCD signalling state '0110' [RFC5244] 151 ABCD signalling state '0111' [RFC5244] 152 ABCD signalling state '1000' [RFC5244] 153 ABCD signalling state '1001' [RFC5244] 154 ABCD signalling state '1010' [RFC5244] 155 ABCD signalling state '1011' [RFC5244] 156 ABCD signalling state '1100' [RFC5244] 157 ABCD signalling state '1101' [RFC5244] 158 ABCD signalling state '1110' [RFC5244] 159 ABCD signalling state '1111' [RFC5244] 160-168 Reserved 169 Unassigned 170-173 Reserved 174 Metering pulse [RFC5244] 175 Trunk unavailable [RFC5244] 176 MFC forward signal 1 [RFC5244] 177 MFC forward signal 2 [RFC5244] 178 MFC forward signal 3 [RFC5244] 179 MFC forward signal 4 [RFC5244] 180 MFC forward signal 5 [RFC5244] 181 MFC forward signal 6 [RFC5244] 182 MFC forward signal 7 [RFC5244] 183 MFC forward signal 8 [RFC5244] 184 MFC forward signal 9 [RFC5244] 185 MFC forward signal 10 [RFC5244] 186 MFC forward signal 11 [RFC5244] 187 MFC forward signal 12 [RFC5244] 188 MFC forward signal 13 [RFC5244] 189 MFC forward signal 14 [RFC5244] 190 MFC forward signal 15 [RFC5244] 191 MFC backward signal 1 [RFC5244] 192 MFC backward signal 2 [RFC5244] 193 MFC backward signal 3 [RFC5244] 194 MFC backward signal 4 [RFC5244] 195 MFC backward signal 5 [RFC5244] 196 MFC backward signal 6 [RFC5244] 197 MFC backward signal 7 [RFC5244] 198 MFC backward signal 8 [RFC5244] 199 MFC backward signal 9 [RFC5244] 200 MFC backward signal 10 [RFC5244] 201 MFC backward signal 11 [RFC5244] 202 MFC backward signal 12 [RFC5244] 203 MFC backward signal 13 [RFC5244] 204 MFC backward signal 14 [RFC5244] 205 MFC backward signal 15 [RFC5244] 206 A bit signalling state '0' [RFC5244] 207 A bit signalling state '1' [RFC5244] 208 AB bit signalling state '00' [RFC5244] 209 AB bit signalling state '01' [RFC5244] 210 AB bit signalling state '10' [RFC5244] 211 AB bit signalling state '11' [RFC5244] 212-255 Unassigned Licensing Terms