This part is about the necessary process for file transmission between two fax terminals on the public telephone exchange network. GB/T 3382.2-2003 Technical conditions for the intercommunication of three types of fax machines in the telephone network Part 2: File fax transmission procedures on the public telephone exchange network GB/T3382.2-2003 standard download decompression password: www.bzxz.net

JCS 33. 040. 70
National Standard of the People's Republic of China
GB/T 3382. 2--2003/ITU-T T 30: 1996Replaces GB/T3382-1993
Technical requirements for group 3 facsimile apparatus used in public telephone network-Part 2. Procedures for document facsimile transmission in the general switched telephone network(ITU-T T. 30:1996,Proccdures for documentfacsimile transmission in thc general switched telephone network,IDT)2003-11-19 Issued by
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
2004-06-01 Implementation
GB/T 3382.2--2003/ITU-T T.30: 1996GB/T3382 "Technical conditions for the interoperability of three types of fax machines in the telephone network" is divided into two parts: Part 1: Standardization of three types of fax terminals for document transmission and extraction; Part 2: Document fax transmission and extraction procedures on public telephone exchanges. This part is the second part of GB/T 3382, corresponding to ITU-T Recommendation T.304 Document fax transmission procedures on public telephone exchanges. The degree of consistency between this part and ITU-T Recommendation T.30 is equal. This part replaces the second part of GB/T3382-1993 "Technical conditions for the interoperability of three types of fax machines in the telephone network": Document fax transmission procedures on public telephone exchanges. This part adopts the TTU-T recommendation T.30 file transmission protocol on the public telephone exchange network (Blue Cover I of the 1996 version, T.30 Amendment 1 (July 1997 version), T.30 Amendment 2 (October 1997 version), and T.30 Amendment 3 (June 1998 version).
Compared with the second part of GB/T 3382-1993, the main changes of this part are as follows: Added the operation method 4 B and 4 B b when using V.8 and YD/T 945 (3.1.5, 3.1.5.1, 3.1.5. 2, Figure 68 and Figure 6b);
-.-Except for the procedures and related signals of G1 (Class-1) and G2 (Class-2) (4.1, 4.2 and 4.3 of the 1993 edition), only the related single tone signals of G3 (Class-3) are retained (4.1 and 4.2 of this edition); - The selected binary coded process data transmission rate of 2400bit/s is deleted (Chapter 5 of the 1993 edition); - The description of using the YD/T853 modulation system is added (Note 4 and Note 5 of Chapter 5 of this edition); - New procedures such as the procedure signal password (PWD), "select polling (SEP)" and "pollinated subaddress (PSA)" are added (5.3.6.1 of this edition). 2,4),5),63):
Add new protocol signals "Subaddress (SUB)" and "Sender Identifier (SID)" (this version 5.3.6.1.3, 4), 5))1-Add new protocol signal "End of Selection (EOS)" (this version 5.3.6.1.6, 7)); Add new protocol signal "Document Diagnostic Message (FDM)" (this version 5.3.6.1, 7, 9)); Add new protocol signal "Invalid Field (FNV)" this version 5.3.6.1.8, 3); Modify the capability list (Table 2), expand the data in the capability list from 40 bits to 104 bits, and increase the corresponding annotations from 10 to 57, clear the content of the table related to Class I and Class II machines (4th to 8th bits), add the content of the YD/T853 modulation system (13th and 14th bits), except for the initial handover with 2400bit/3 ( 25th position), remove the error correction mode and the ability of Category 4 machines on the public telephone exchange network (29th and 30th positions), and remove the requirements for A4 and A5 size paper documents (34th to 37th positions) (1993 edition and Table 2 of this edition)
- Add PWD encoding format (5.3.6.2.8 of this edition); - Add SEP encoding format (5.3.6.2.9 of this edition); - Add SUB encoding format (5.3.6.2.10 of this edition); - Add SID encoding format (5.3.6.2.11 of this edition): Add FNV encoding format (5.3.6.2.12 of this edition) Add PSA encoding format (5.3.6.2.13 of this edition); Add time limit T0 (5.4.3.1 of the 1993 edition and this edition); - Add a chapter on the use of modulation systems defined in YD/T945 (Chapter 6 of this edition):. ：Deleted the flowchart of the error correction method. And changed the original Figure A.26 to Figure A.7 (Figure A.7 ~ A.25 of Chapter A.7 of the 1993 edition. Figure A.7 of Chapter 8 of this edition).
--Deleted the flowchart index of the error correction method (Chapter A.7.1 of the 1993 edition); GB/T3382.2-2003/FTU-TT.30:1996 deleted the content of the original Appendix B "Examples of non-standard basic fax operations from human to human", and added a new Appendix B\BFT diagnostic message" (Appendix B of the 1993 edition and this edition);-Added Appendix C\Three types of document fax transmission using duplex modulation system on the integrated services digital network or public telephone exchange network - Add Appendix D "Optional Automatic Terminal Selection Specifications", change the original Appendix D "Commands and corresponding response list" to Annex II (Appendix D of the 1993 edition, Appendix D and Annex II of this edition); - Add Appendix F "Three types of document fax transmission procedures for continuous tone color images", delete the original Appendix F "Binary code initial handover process used when intercommunication between standard mode and recognized optional mode" (Appendix E of the 1993 edition and this edition); - Add Appendix F "Procedures for the transmission of Class 3 fax using the half-duplex modulation system defined in YD/T945", change the original Appendix F "Examples of signal sequences" to Annex NV, and change the name to Examples of signal sequences" (Appendix F of the 1993 edition, Annex to Appendix F of this edition)
- Add Appendix G "Procedures for the transmission of secure Class 3 document fax using HKM and HFX systems" (Appendix G of this edition); Add Appendix H "Security in Class 3 fax based on RSA algorithm" (Appendix H of this edition); Add Appendix Added Appendix I\Three-dimensional file fax transmission procedures for color and grayscale images using T.43" (Appendix I of this edition); Added Appendix J\Three-dimensional file fax transmission procedures for mixed raster content (MRC) images" (Appendix J of this edition); Added Annex "Alternative procedures for use by certain terminals that conform to previous versions of this part\ (Appendix III of this edition); Added Annex V\Protocol examples for binary file transmission procedures" (Appendix V of this edition); - Added examples of combining and changing various image parameters using DIS/DIC and DCS negotiation functions (Appendix I of this edition). Appendix A, Appendix B, Appendix C, Appendix D, Appendix E, Appendix F, Appendix G, Appendix H, Appendix I and Appendix II of this part are normative appendices, and Annex I, Annex II, Annex III, Annex V and Annex III are informative. This part was proposed by the Ministry of Information Industry of the People's Republic of China. This part is under the jurisdiction of the Telecommunications Research Institute.
Drafting unit of this part: Telecommunications Transmission Research Institute. The main drafters of this part are Cui Jinshui, Gou Yali, Li Shidong, Shi Xiaorui, and Han Guojie. The previous versions of the standards replaced by this part are: GB/T3382--1982. GB/T3382-1985. GB/T3382-1991, GB/T3382-1993. Introduction
GB/T3382.2-2003/ITU-T T.30:1996 The national standard GB/T3382 for the three types of document fax machines has been implemented for 20 years. It has played an important guiding role in the application and development of the three types of fax machines in my country. GB/T3382 is based on the ITU-T (International Telecommunication Union-Telecommunication Standardization Department) recommendation T.4 Standardization of three types of fax terminals for file transmission\ and T.30 on the public telephone exchange network. With the development of fax communication technology, ITU-T has made substantial revisions and expansions to Recommendations T.4 and T.30, deleting technical contents that have proved to have no application value in actual use, and adding various new technical requirements. At present, these new technologies have been widely used in new fax machines. Therefore, GB/T 3382 is revised again, and new technical contents are added to adapt to the development of technology and application requirements. This part is the second part of the revised GB/T3382, corresponding to ITU-T Recommendation T.30. 1) This part applies to file fax terminals defined in GB/T3382.2. This part describes the processes and signals of fax terminals working on the public telephone exchange network. When existing terminals work in a non-standard manner, terminals that work in a standard manner must be available. II) The arrangements for automatic calling/answering on the public telephone exchange network should be consistent with the provisions for data terminal equipment in the ITU-TV series of recommendations as much as possible.
Ⅱ) There are 8 possible modes of operation, each of which can be described by five independent but connected phases: Phase A: Call establishment;
Phase B: Pre-message process for identification and selection of the required equipment; Phase C: Call transmission (including corresponding phases and synchronization); Phase F: Post-message process, including message completion, confirmation and multi-page process; Phase F: Call release.
I) For digital document fax terminals that comply with GB/T3382.2, the standard signal arrangement is the binary coding system specified in this part. V) The binary coding system is based on the format of the high-level link control procedure (HDLC) for data transmission. The basic HDLC structure consists of several frames, each of which is divided into several fields. The fields provide identification, error checking and confirmation of correct receipt of information for the frame. Moreover, these frames can be easily expanded when necessary. И) The transmission of the fax message itself (phase C) should be carried out according to the modulation method specified by the relevant standards for fax terminals. Normative references
The clauses in the following documents become clauses of this part through reference in this part of GB/T 3382. For any dated referenced document, all subsequent amendments (excluding errata) or revised editions are not applicable to this part; however, parties to agreements based on this part are encouraged to investigate whether the latest versions of these documents can be used. For any undated referenced document, the latest version applies to this part.
GB/T 3382.1-2003 Technical conditions for interoperability of group 3 fax machines in telephone networks Part 1: Standardization of group 3 fax terminals for file transmission (ITU-TT.4:1996, Standardization of group 3 fax terminals fordocument(ransmissionIDT)
GB/T7616-1987 Equivalence between binary representation symbols and meaningful states of two-state codes (eqvITU-T V.1:1984)
GB/T7620-1987 Standardized 300 bit/s full-efficiency modem for use in the telephone automatic switching network (eqvITU-T Recommendation V.21; 1984)
GB/T14805-1993 Grammar rules for electronic data interchange for administration, commerce and transport (idtISO9735:1.988)
YD/T853-1996 Technical requirements for two-wire modems for fax with a rate of up to 14400 bit/s (eqvITU-T Recommendation V.17) YD/T945-1998 Data signal rates up to 33600 for use in the public telephone switching network and point-to-point two-wire dedicated circuits 3382.2—2003/ITU-T T,30: 1996 bit/s modem (idt ITU-T Recommendation V.34) YD/T951--1998 Characteristics and protocols of ISDN telematics service end (eqvITU-T Recommendation T.90) 1 ITU-T Recommendation F.551 (1993) Service recommendations for telematics document transmission in three-category user fax, four-category user fax, intelligent user telegraph service and message processing service ITU-T Recommendation T.35 (1994) CCITT defined regulations for the allocation of non-standard push facility codes ITU-T Recommendation T.36 (1997) Class III fax terminal use ITU-T Recommendation T.42 (1994) Method for the representation of continuous-tone colours for fax ITU-T Recommendation T.43 (1997) Method for the representation of colour and greyscale images using a non-destructive coding scheme for fax ITU-T Recommendation T.434 (1996) Binary file transfer format for telematic services ITU-T Recommendation T.44 (1997) Mixed Resonance Content (MRC) A file application for the interchange of mixed content files in processable and formatted forms ITU-F Recommendation T. 505 (1991)
Profile PM-26
Batch file transfer over session-based services Communication application profile BTO (based on the rules defined in Recommendation T.62-ITU-T Recommendation T.521 (1994)
)
ITU-T Recommendation T.82 (1993) Information technology - Coded representation of video and speech information - Inverse incremental two-level image compression ITU-T Recommendation T.85 (1995) Application profile of Recommendation T.82 - Incremental two-level image compression (JBIG coding scheme) for facsimile equipment
ITU-T Recommendation V.8 (1998) in public telephone exchanges Procedure for initiating a session for data transmission over the Internet JTU-T Recommendation V.27 Standardized 4800/2400 bit/s modems for use in public data networks ITU-T Recommendation V.29 Standardized 9600 bit/s modems for use on point-to-point four-wire leased telephone-type circuits ITU-T Recommendation V.33 (1988) Standard for 14400 bit-per-second modems for use on point-to-point four-wire leased telephone-type circuits ITU-T Recommendation X680 (1997) IS0/[FC8824-1:1998 Information technology - Object Syntax Notation 1 (ASN.1): Specification of the basic notation tt||CCITT Recommendation T.6 (1988) Fax Coding Schemes and Coding Control Functions for Group 4 Fax Machines (General Reference for MIMR Standards)CCITT Recommendation T.81 (1992)/ISO/IEC10918-1:1994 Information Technology - Digital Compression and Coding of Continuous-tone Still Images - Requirements and Criteria (General Reference for JPEG Standards)CCITT Recommendation X.209 (1988) Specification of Basic Encoding Rules for Abstract Syntax Notation 1 (ASN.1)IS0/IEC9796 Information Technology Security TechniquesDigital Signature Schemes with Message RecoveryISO/IEC10118-3?1 998 Information technology security technology Hash functions Part 3: Special hash functions IS0/IEC9979:1999 Information technology encryption technology Registration procedures for encryption algorithms IS0/IEC14888-3:1998 Information technology security technology Mathematical signatures with appendix Part 3: Certificate-based mechanisms
RFC1321MD-5: Message Digest Algorithm
CIF Publication, 15.2 Color Determination, Second Edition, 1986FIPSPUB186-1: Digital Signature Standard, U.SNIST, February 1, 1993 1 Scope
1.1 Overview
GB/T 3382. 2—2003/ITU-T T. 30: 1996 Technical conditions for interworking of three types of fax machines in the telephone network Part 1 Procedure for document fax transmission on the public telephone exchange network 1.1.1 This part is about the necessary procedures for document transmission between two fax terminals on the public telephone exchange network. These procedures basically include the following aspects: 1 Call establishment and call release;
compatibility check, status and control commands; line status check and monitoring
-control functions and re-calling the operator.
1.1.2 This part only specifies the procedures with these related signals. 1.2 Classification of operation methods
1.2.1 This part specifies the operating sequence of manually operated fax terminals and automatic terminals. Automatic fax terminals refer to terminals that have the ability to automatically perform all the procedures (listed in 1.1). In this case, no operator is required. bzxZ.net
However, if any of these procedures require an operator, the terminal shall be considered as a manually operated terminal. 1.2.2 Based on the fact that there are all possible combinations of manually operated terminals and automatic fax terminals, the operation methods shown in Table 1 are all possible.
Method number
Operation method description
Calling terminal manual operation and
Calling terminal manual operation
Calling terminal manual operation and
Called terminal automatic operation
Calling terminal automatic operation and
Calling terminal manual operation
Calling terminal automatic operation and
Called terminal automatic operation
Calling terminal usage recommendation V. 8 The procedure defined in the automatic operation
The calling terminal uses the recommended V, 8 procedures defined in the automatic operation
Fax transmission direction
Calling terminal sends to called terminal
Calling terminal receives from called terminal
Calling terminal sends to called terminal
Calling terminal receives from called terminal
Calling terminal sends to exclusive calling terminal
Calling terminal receives from called terminal
Calling terminal sends to other terminal
The calling terminal receives from the called terminal
Using the procedures defined in Recommendation V,8
The calling terminal sends to the called terminal
Quickly using the procedures defined in Recommendation V,8
The calling terminal receives from the called terminal
Note: There may also be an operation method that allows multiple terminals to receive the message [multipoint connection), 1.3 Terminal identification
Combined symbolic representation
1.3.1 In order to classify the automatic fax terminal as a non-voice terminal, a single tone must be sent to the line. Because the automatic calling and 1) The three types of fax terminals involved in this part are all consistent with the provisions of GB/T3382.1. 1
GB/T 3382.2—2003/1TU-T T. 30 : 1996 The called fax terminal sends a single tone in both directions. If a telephone user accidentally connects to a terminal, he will receive a single tone signal of sufficient duration to indicate that he is connected incorrectly. 1.3.2 In addition, automatic voice announcement can be used to provide full terminal identification. 1.4 Provisions
1.4.1 The control signals specified in this section are selected without affecting telephone service. 1.4.2 If any failure of the fax process described in this section is detected, the call should be released. 1.4.3 When a called destination equipped with an automatic fax terminal is not ready or cannot be operated, the call should not be automatically answered. 1.4.4 This section includes the process of switching from fax to conversation. However, if permitted by the regulations of the competent authority, the conversation device can be omitted. 1.5 Optional Provisions
1.5.1 During the facsimile process (see 2.2), the operator of each terminal has the possibility to call the other terminals at any time. 1.5.2 The procedures in this standard allow a facsimile terminal to send and/or receive multiple copies of a document continuously without the need for the assistance of an operator. 1.5.3 If it is necessary to prevent unauthorized terminals from obtaining messages, this standard includes procedures for encoding a specific terminal identification command. If increased security is required, non-standard features may be used. 2 Terms and Definitions
The following definitions apply to this standard.
Facsimile Terminal Main Functionfacsimile Terminal Main FunctionOne or more terminals at the end of a line provide three main functions. 2.1.1
Call Establishment and Call Releasecall establishment and call releaseEstablish and release connections in accordance with the normal rules used in the public switched telephone network. 2.1.2
ProcedureprocedureIdentification, monitoring and control of facsimile transmissions according to the protocol. 2. 1. 3
Tmessage transmission
Message transmission
Sending and/or receiving fax messages.
The chronological sequence of a fax call
is shown in Figure 1.
Message transmission
Phase A
Cyclic sequence
Section 1
Section C2
Message transmission
Fax process
Fax call
2.3 Description of phases
2,3. 1 Phase A—Call establishment
Call establishment can be achieved manually and/or automatically. 2.3.2 Phase B—Pre-message process
GB/T3382.2-2003/1TU-T T.30:1996 The pre-message process consists of capability identification, command transmission of selected conditions, and confirmation of acceptable conditions. When a connection is established between a terminal operating in accordance with this part and a terminal operating in a manner not in accordance with this part, the terminal must disconnect the connection before entering the message process, unless both ends include optional and compatible processes. 2.3.2.1 Identification part
—…capability identification;
:-acceptance confirmation:
-end error (optional):
: non-standard equipment identification (optional).
2.3.2.2 Command part
Capability command:
training,
-synchronization.
and the following optional commands;
-Non-standard equipment command;
-Terminal identification command!
-Polling (sending) command!
-Echo suppressor release,
2. 3. 3 Phase C1-
-Message process
The message process is arranged in the same period as the message transmission and controls all the signals of the message process, such as message synchronization, error detection and correction, and line monitoring. 2. 3. 4 Section C2-Message transmission
The message transmission process included in GB/T3382.1. 2.3.5 Phase D—Post-message process
The post-message process includes the following information:
--a message end signal;
confirmation number;
a multi-page signal:
a fax release end signal.
2.3.6 Phase E—Call release
Call release can be realized manually and/or automatically. 3 Fax call description
3.1 Phase A—Call establishment 1
The establishment of a fax call can be realized manually (if an operator is on duty) or automatically. Four operation methods are specified to complete this stage.
When the calling end operates automatically, the terminal that complies with this standard uses timer T0 (except GB/T3382-1993 and previous versions). Timer TO is described in detail in 5.4.3.1.
1) For the abbreviations used in this part, see Annex I. 3
GB/T33B2.2—2003/JTU-T T.30:19963, 1. 1 Operation method 1
Both the calling and called terminals are operated manually. Figure 2 shows the actions taken by the operator to establish a call. 3. 1.2 Operation method 2
The calling terminal is operated manually, and the called terminal is operated automatically. Figure 3 shows the actions required by the operator to establish a call. 3,1.3 Operation method 3
The calling terminal is operated automatically, and the called terminal is operated manually. Figure 4 shows the actions required by the operator and the terminal to establish a call. 3.1.4 Operation method 4
Both the calling and called terminals are operated automatically. Figure 5 shows the actions required by the terminal to establish a call. 3.1.5 Operation Method 4 B
3.1.5.1 Operation Method 4 Z is
When both or either of the calling or called terminals have ITU-T Recommendation V.8 and YD/T945 operation capabilities, both the calling and called terminals are manually operated. Figure 6a indicates the actions required by the terminals to establish a call. 3.1,5,2 Operation Method 4 B 6
When both or either of the calling or called terminals have ITU-T Recommendation V.8 and YD/T945 operation capabilities, the calling terminal is manually operated and the called terminal is automatically operated. Figure 6 indicates the actions required by the terminals to establish a call. 3.2 Phase B, C and D - Fax Process When entering Phase R, the following rules must be followed. All receiving terminals and stored automatic answering terminals must identify their capabilities before entering Phase B (i.e., node R in the flowchart of 5.2). All manual sending terminals and all automatic call processing terminals enter phase B to detect capabilities and issue appropriate mode setting commands (node ​​T in the flowchart in 5.2). In order to facilitate the use of operation method 2-R, the delay between the transmission of the +digital identification signal when sending from a manual receiving terminal should be 4.5×(1±15%)s. Detailed information about the binary coded fax process is included in Chapter 5. 3.2.1 Sequence of messages
The proposed system uses signal interchange between the two terminals to verify compatibility and ensure operation. To this end, the called terminal identifies its capabilities. The calling terminal responds to this with a command response. The sender then continues with phase B. After the message has been transmitted, the sender sends an end-of-message signal and the receiver confirms receipt of the message. Multiple files can be transmitted by repeating this process.
Figure 7 shows the signal flow configured when the calling terminal sends. Figure & shows the state of the calling terminal when receiving a file. 3.3 Phase E - Call release
Call release occurs after the last post-message signal of the process or under certain circumstances, for example: 3.3.1 Time limit
If the signal specified in the fax process is not received within the specified time limit range, the receiving terminal may signal the operator (if one of the parties is manned) or disconnect the telephone connection. Chapter 5 specifies the appropriate time limit range. 3.3.2 During the process, the fax process can be interrupted by sending a process interrupt signal, notifying the operator on duty or disconnecting the connection. This signal is specified in Chapter 5.
3.3.3 Command
GB/T 3382. 2-2003/1TU-TT, 30:1996 The call can be terminated immediately by using the appropriate command as specified in Chapter 5. Calling event number
Calling terminal
Operator hears dial tone and calls the required number Operator hears ringing tone
Verbal identification
Switch the fax terminal to the line and send C:NG to start the fax process (see Chapter 4 and/or 5) 3. The single
hears the dial tone Customer
receives the return?
Oral exchange
Fax machine dials line H
Sends a blockage (NG
Enters stage B
Disconnectable
Called end
Call rings, and operator answers call
Oral identification
Switch fax machine to line
Start fax process (see Chapter 4 and/or 5)
Effective call through end
Receives short number:
Answer call
Oral exchange
The fax machine is connected to the line
(cross-use)
Sends CED
Enters stage B
Figure 2 Call establishment, operation method 1
GB/T 3382. 2-2003/ITU-T T. 30: 1996 Call event trigger
Calling terminal
Operator hears dial tone and dials required numberOperator hears recording tone
Operator hears CED or selected recorded notification and switches fax terminal to line and sends CNG
Start fax process (see Chapter 4 and/or 5)Calling bee hears
New number?
Fax machine switches to upper line
Sends CNG
Enters phase B
Disconnects connection
Disconnects processing
Called terminal
Checks arrival and responds to call
Optionally, recorded oral notification can be sentSends CEL
Starts fax process (see Chapter 4 and/or 5)
Called terminal This adds
detection data
prepare for operation
answer call
(optional)
final tone notification
send CED
enter B
node R
Figure 3 Call establishment, detection method 2
call event number
calling terminal
terminal detects dial tone and dials the required number (Note). In order to clearly indicate to the called operator that he is connected to a fax terminal, or to alert ordinary telephone users that they are connected incorrectly, a CNG is sent to the line during the detection signal
starting the fax process (see Chapters 4 and/or 5) Note: The competent authority may determine an alternative process. The calling party dials
detects the fax number
GB/T 3382.2—2003/1TU-T T. 3D: 1996Called terminal
Call vibrates and operator answers the call
Operator detects CNG and switches the fax terminal to the line (optionally, CED may be generated)
Start fax process (see Chapter 4 and/or 5)Call ends
Hear the call?
Mutual call
Start TO
Send GNG
Output letter
Enter stage day
Node T
TO arrives
Disconnect
Detect CNG
Fax machine switches to strategy, F
(optional)
Send CED
Enter stage B
Figure 4 Call establishment, operation method 3
When the time comes?
Disconnect reverse connectionRecorded verbal notification may be sent Send CEL
Start fax process (see Chapters 4 and/or 5)
Called party This adds
Detection data
Prepare for operation
Answer call
(optional)
Last voice notification
Send CED
Enter B
Node R
Figure 3 Call establishment, operation method 2
Calling event number
Calling party
Terminal detects dial tone and dials the required number (Note). In order to clearly indicate to the called operator that he is connected to a fax terminal, or to alert ordinary telephone users that they are connected incorrectly, CNG is sent to the line during the detection signal
Start fax process (see Chapters 4 and/or 5) Note: The competent authority may determine an alternative process. Calling terminal
Detects the fax number
GB/T 3382.2—2003/1TU-TT. 3D: 1996Called terminal
The call vibrates and the operator answers the call
The operator detects CNG and switches the fax terminal to the line (optionally, a CED may be generated)
Starts the fax process (see Chapter 4 and/or 5)Calling terminal
Hear the voice?
Ma Mu call
Start TO
Send GNG
Out of the letter
Enter stage day
Node T
TO time
Disconnect
Check CNG
Fax machine switches to strategy, F
(optional)
Send CED
Enter stage B
Figure 4 Call construction, operation method 3
Time?
Disconnect reverse connectionRecorded verbal notification may be sent Send CEL
Start fax process (see Chapters 4 and/or 5)
Called party This adds
Detection data
Prepare for operation
Answer call
(optional)
Last voice notification
Send CED
Enter B
Node R
Figure 3 Call establishment, operation method 2
Calling event number
Calling party
Terminal detects dial tone and dials the required number (Note). In order to clearly indicate to the called operator that he is connected to a fax terminal, or to alert ordinary telephone users that they are connected incorrectly, CNG is sent to the line during the detection signal
Start fax process (see Chapters 4 and/or 5) Note: The competent authority may determine an alternative process. Calling terminal
Detects the fax number
GB/T 3382.2—2003/1TU-TT. 3D: 1996Called terminal
The call vibrates and the operator answers the call
The operator detects CNG and switches the fax terminal to the line (optionally, a CED may be generated)
Starts the fax process (see Chapter 4 and/or 5)Calling terminal
Hear the voice?
Ma Mu call
Start TO
Send GNG
Out of the letter
Enter stage day
Node T
TO time
Disconnect
Check CNG
Fax machine switches to strategy, F
(optional)
Send CED
Enter stage B
Figure 4 Call construction, operation method 3
Time?
Disconnect reverse connection
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