--- ISDN D channel --- Device: COM3 [USB Serial Port] Line 1 No. : 149 Date : 21.01.2026 Time: 03:33:57:180 Length: 31 Direction: Net -> User CRC : Ok --- HEX Data --- 02 01 00 00 08 02 00 05 05 A1 04 03 80 90 A3 18 03 A9 83 81 70 05 80 35 30 30 35 7D 02 91 81 --- Layer 2 Data Link --- 000 02 000000-- SAPI : 0 Call control procedures ------1- C/R : 1 Command (Net -> User) -------0 EA : 0 Octet extended 001 01 0000000- TEI : 0 Non-automatic -------1 EA : 1 Final octet 002 00 0000000- N(S) : 0 -------0 Format : 0 Information Type : I 003 00 0000000- N(R) : 0 -------0 P : 0 not set --- Layer 3 --- 004 08 00001000 PD : 8 Q.931 user-network call control messages 005 02 0000---- Reserved ----0010 CR length: 2 006 00 0------- CR flag : 0 Origination -0000000 007 05 00000101 CR : 5 008 05 0------- Reserved -0000101 Message : 5 SETUP --- Layer 3 information elements --- 009 A1 1------- Type : 1 Single Octet -0100001 IE : 33 Sending complete ------------------------------------ 010 04 0------- Type : 0 Variable Length -0000100 IE : 4 Bearer capability 011 03 00000011 Length : 3 012 80 1------- Extension : 1 Final octet -00----- Coding standard : 0 CCITT standardized coding ---00000 Info transf. capabil.: 0 speech 013 90 1------- Extension : 1 Final octet -00----- Transfer mode : 0 circuit Mode ---10000 Info transf. rate : 16 64 kbit/s 014 A3 1------- Extension : 1 Final octet -01----- Layer identifier : 1 Layer 1 identifier ---00011 User info L1 protocol: 3 Rec. G.711 A-law ------------------------------------ 015 18 0------- Type : 0 Variable Length -0011000 IE : 24 Channel identification 016 03 00000011 Length : 3 017 A9 1------- Extension : 1 Final octet -0------ Interface ident. pre.: 0 interface implicitly identified --1----- Interface type : 1 other interface ---0---- Spare : 0 Constant ----1--- Preferred/exclusive : 1 exclusive: only the indicated channel is acceptable -----0-- D-channel indicator : 0 the channel identified is not the D-channel ------01 Info channel select. : 1 as indicated in following octets 018 83 1------- Extension : 1 Final octet -00----- Coding standard : 0 CCITT standardized coding ---0---- Number / Map : 0 channel is indicated by the number in the following octet ----0011 Channel type : 3 B-channel units 019 81 1------- Extension : 1 Final octet -0000001 Channel number : 1 ------------------------------------ 020 70 0------- Type : 0 Variable Length -1110000 IE : 112 Called party number 021 05 00000101 Length : 5 022 80 1------- Extension : 1 Final octet -000---- Type of number : 0 unknown ----0000 Numbering plan ident.: 0 unknown 023 35 0------- Spare : 0 Constant -0110101 Number digit : 53 '5' 024 30 0------- Spare : 0 Constant -0110000 Number digit : 48 '0' 025 30 0------- Spare : 0 Constant -0110000 Number digit : 48 '0' 026 35 0------- Spare : 0 Constant -0110101 Number digit : 53 '5' "5005" ------------------------------------ 027 7D 0------- Type : 0 Variable Length -1111101 IE : 125 High layer compatibility 028 02 00000010 Length : 2 029 91 1------- Extension : 1 Final octet -00----- Coding standard : 0 CCITT standardized coding ---100-- Interpretation : 4 First (primary only) high layer characteristics identification (in octet 4) to be used in the call ------01 Present. method : 1 high layer protocol profile (without specification of attributes) 030 81 1------- Extension : 1 Final octet -0000001 High layer char. id. : 1 Telephony ------------------------------------ --- ISDN D channel --- Device: COM3 [USB Serial Port] Line 1 No. : 150 Date : 21.01.2026 Time: 03:33:57:210 Length: 14 Direction: User -> Net CRC : Ok --- HEX Data --- 00 01 00 02 08 02 80 05 02 18 03 A9 83 81 --- Layer 2 Data Link --- 000 00 000000-- SAPI : 0 Call control procedures ------0- C/R : 0 Command (User -> Net) -------0 EA : 0 Octet extended 001 01 0000000- TEI : 0 Non-automatic -------1 EA : 1 Final octet 002 00 0000000- N(S) : 0 -------0 Format : 0 Information Type : I 003 02 0000001- N(R) : 1 -------0 P : 0 not set --- Layer 3 --- 004 08 00001000 PD : 8 Q.931 user-network call control messages 005 02 0000---- Reserved ----0010 CR length: 2 006 80 1------- CR flag : 1 Destination -0000000 007 05 00000101 CR : 5 008 02 0------- Reserved -0000010 Message : 2 CALL PROCEEDING --- Layer 3 information elements --- 009 18 0------- Type : 0 Variable Length -0011000 IE : 24 Channel identification 010 03 00000011 Length : 3 011 A9 1------- Extension : 1 Final octet -0------ Interface ident. pre.: 0 interface implicitly identified --1----- Interface type : 1 other interface ---0---- Spare : 0 Constant ----1--- Preferred/exclusive : 1 exclusive: only the indicated channel is acceptable -----0-- D-channel indicator : 0 the channel identified is not the D-channel ------01 Info channel select. : 1 as indicated in following octets 012 83 1------- Extension : 1 Final octet -00----- Coding standard : 0 CCITT standardized coding ---0---- Number / Map : 0 channel is indicated by the number in the following octet ----0011 Channel type : 3 B-channel units 013 81 1------- Extension : 1 Final octet -0000001 Channel number : 1 ------------------------------------