(Page 1 of 1 in this chapter)

Appendix A

Glossary


A3 ISO page size 11.9" x 16.5" (303 mm x 420 mm)
A4 ISO page size 8.25" x 11.6" (210 mm x 297 mm)
B4 ISO page size 10" x 14" (255 mm x 353 mm)
CED CallED tone; the 3-second 2100 Hz tone a called fax terminal places on the line to indicate that the called station is a fax terminal.
CIG CallInG subscriber identification; used in fax polling by the calling fax terminal to identify itself. The CIG is defined by ITU T.30 as the calling station's international telephone number, and can contain up to 20 characters.
CNG CalliNG tone; the 0.5 second, 1100 Hz tone placed on the line every 3 seconds until CED is received. The CNG tone indicates a fax terminal is calling.
CSI Called Subscriber Identification; an optional frame used by the called fax terminal to give its international telephone number, which can contain up to 20 characters.
DCN DisCoNnect frame; a disconnect message sent by the calling fax terminal to the remote fax terminal before the calling fax terminal releases the call. The calling fax terminal can release the call as soon as it sends the DCN frame; it does not need to wait for a response from the remote terminal. See also Group 3, T.30.
DCS Digital Command Signal; the setup command used by the calling fax terminal in response to DIS. The DCS determines the attributes of the fax transmission to follow (transmission speed, resolution, etc.).
DIS Digital Identification Signal; used by the called fax terminal to communicate its capabilities to the calling fax terminal.
document The image entity to be transmitted; it is contained in a single file, and can contain more than one page. Documents to be transmitted by NaturalFax must be in TIFF-F format. Documents received by NaturalFax are stored in TIFF-F format.
document queue A NaturalFax data structure that contains references to documents. A document queue must be either a send queue or a receive queue; only send queues can be sent, and only receive queues can be used to receive documents.
DTC Digital Transmit Command; used by the calling fax terminal to poll the called fax terminal.
ECM Error Correction Mode; a T.30 option which can be used to correct transmission errors. The receiver uses checksum information to verify that the image data received matches what was transmitted. If it is does not match, the receiver can request retransmission of a portion of the data. This option is useful when noisy telephone line conditions are expected.
fax license unit Fax license units are used to measure and control the number of active fax units in a system. If an application does not explicitly allocate fax license units, the NaturalFax functions will automatically allocate fax license units as required.
fax session According to the ITU T.30 specification, and as used in NaturalFax, the portion of a fax transfer operation which begins with the called fax terminal sending its capabilities (Phase B) to the calling application or fax terminal and ends with the calling fax terminal commanding a disconnect (Phase E). See also Group 3 fax, Phase B, Phase E, T.30.
fax store-and-forward A fax application that receives a fax image, stores it temporarily, and forwards the image to its final destination. Typical fax store-and-forward applications include "never busy fax" applications, and applications which transmit a fax image to a remote fax gateway over the IP network. NaturalFax supports these types of fax store-and-forward applications.
Group 3 fax A fax protocol published in 1980 by the ITU. Group 3 protocol is specified in several standards: T.4 and T.6 specify the image format, T.30 specifies the session management protocol which supports the establishment of a fax transmission. Since Group 3 protocol is specified for the switched analog network, and it is an all-digital procedure, it must use modems.
ITU The International Telecommunications Union (ITU) is the international standards body for telecommunications.
MMR Modified Modified Read; an encoding format for fax documents that is more compact than MH or MR encoding for most images.
NSF Non-Standard Facilities frame; a nonstandard frame as specified by the ITU T.30, the Group 3 fax standard. This frame is sent by the calling fax terminal in response to the called fax terminal's DIS frame.
NSS Non-Standard Set Up frame; a nonstandard frame as specified by the ITU T.30, the Group 3 fax standard. This frame is sent by the called fax terminal in response to the calling fax terminal's DCS frame.
NSC Non-Standard facilities Command frame; a nonstandard frame as specified by the ITU T.30, the Group 3 fax standard. This frame is sent by the calling fax terminal to command the called fax terminal to send (a poll).
Non Standard Facilities Frames
ITU T.30 allows a non-standard message, one whose contents are not specified by T.30, to be included with most negotiations. These non-standard frames are called NSF (Non-Standard Facilities) when the called fax terminal sends DIS, NSS (Non-Standard Setup) when the calling fax terminal responds to DIS with DCS, and NSC (Non-Standard facilities Command) when commanding the called fax terminal to send (a poll).
A non-standard frame begins with the country code of the manufacturer, the manufacturer's code, and any additional ASCII information (limited by allowable transmission time of three seconds). The non-standard frame transmitted by the remote terminal will only be read if the first three bytes match the Country Code and manufacturer's ID parameters for the local terminal.
Phase A The call setup phase of the T.30 protocol.
Phase B The pre-message procedure for identifying and selecting call-specific facilities in the T.30 protocol.
Phase C The image transfer phase of the T.30 protocol.
Phase D The post-message procedures (EOM and multi-document procedures) of the T.30 protocol.
Phase E The call release phase of the T.30 protocol.
polling A fax operation in which the calling fax terminal requests that the called fax terminal send documents to the calling fax terminal. This is also known as turnaround polling.
PRI PRocedure Interrupt; a signal to the remote fax terminal which requests the remote fax terminal to permit operator interaction. A PRI signal is used to request that the remote fax terminal allow operator intervention, such as voice communications over the handset, and requests the remote fax terminal keep the call connected (i.e., not to hang up the call) at the end of a fax session.
receive queue A NaturalFax document queue for receiving documents transmitted from one fax terminal to another. A receive queue must have an allocated entry for each document to be received. Only names of files that do not exist can be enqueued in a receive queue; the file names may not be NULL.
send queue A NaturalFax document queue for sending documents from one fax terminal to another. Only files that already exist can be added to a send queue. The same file can be placed in multiple send queues simultaneously.
store-and-forward See fax store-and-forward.
TIFF Tagged Image File Format; a graphics file format characterized by the use of "tags" to specify the format of the file.
TIFF-F A class of TIFF file intended for use in fax applications. It supports storing multipage fax documents in one file.
TSI Transmitting Subscriber Identification; used by the transmitting fax terminal to identify itself. Defined as an international telephone number that can contain up to 20 characters.
T.4 The standard which defines Group 3 image format for MH and MR encoding. See also Group 3, ITU.
T.6 The ITU standard which defines Group 3 MMR image encoding. See also Group 3, ITU, MMR.
T.30 The ITU standard which defines the negotiating procedures and session management for Groups 1, 2, and 3 fax. T.30 divides a fax session into five phases, A through E. See also Group 3, ITU, Phase A, Phase B, Phase C, Phase D, Phase E.
training Negotiation between the modems of the called fax terminal and the calling fax terminal in which the fax terminals attempt to communicate and agree on a rate and modem type for image transfer.
V.17 The 7200/9600/12000/14400 bps modem which is used for Group 3 fax.
V.21 The 300 bps modem used for Group 3 fax negotiations.
V.27ter The 2400/4800 bps modem which is used for Group 3 fax.
V.29 The 7200/9600 bps modem which is used for Group 3 fax.

(Page 1 of 1 in this chapter)

tech_support@nmss.com