AddPac IPNext190 Installation Manual page 125

IPNext 190 System Installation Guide
FAX
Frame
Frame-Relay
FTP
FXO
FXS
G.711
G.723.1
2, 10Base5, 10Base-F, 10Base-T, 10Broad-36, Fast Ethernet, and IEEE 802.3.
Abbreviation of Facsimile. FAX refers to the transmission of scanned texts or images to a
printer or an output device connected to another phone number by using a telephone line.
Once the original document is read by a facsimile, the facsimile treats the document as a
fixed graphic image, and converts it to bitmap. In this digital form, data is transferred in the
form of an electrical signal through a phone system. The receiving facsimile restores the
data to a encoded image, and prints it on a sheet of paper.
Logical group of data transferred to a data link layer unit through a transmission medium.
From frames, the header and trailer that include user data are important. Headers and
trailers are used for synchronization and error control. Cells, datagrams, messages, packets,
and segments are used to describe logical data groups in various layers of OSI or based on
various technologies.
This is an industry-standard switching-type data link layer protocol that processes multiple
virtual lines in inter-connected devices by using the HDLC encapsulation. Frame-Relay is
more efficient than X.25.
Stands for File Transfer Protocol. FTP, which is an application protocol, is part of the
TCP/IP protocol stack used for file transfer between network nodes. FTP is defined in RFC
959.
Stands for Foreign Exchange Office. The FXO interface is connected to the switching
center of Public Switched Telephone Network (PSTN), and is provided by a regular phone.
The FXO interface of Cisco is a station interface of the switching center or PBX on PSTN,
and is a RJ-11 connector for analog connection devices.
Stands for Foreign Exchange Station. The FXS interface is directly connected to a standard
phone, and provides a ring-back tone, voltage, and a dial tone. The FXS interface of Cisco
is a RJ-11 connector for basic telephone service devices, keyset, and PBX.
This specifies the PCM voice coding technique of 64Kbps. Voice is encoded under G.711 in
an appropriate format that enables digital voice transmission over either PSTN or PBX.
G.711 is specified under the ITU-T standard of G-series recommendation.
This is one of the H.324 standards, and specifies a compression technique that enables
voice or audio signal elements to be compressed at a very low bit transmission rate. This
CODEC is related to the bit transmission rates of 5.3Kpbs and 6.3Kpbs. The high bit
transmission rate is based on the MLMLQ technology, and provides high quality sounds.
The low bit transmission rate is based on CELP, and ensures high flexibility for system
designers. This standard is specified under the G-series ITU-T standard.
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