Multi-Tech Systems Mvp400, Mvp800 Voice/fax Over Ip Networks User Guide

							91 Appendix C - Regulatory Information
Appendix C - Regulatory Information
Class A Statement
FCC Part 15
NOTE: This equipment has been tested and found to comply with the limits for a Class A digital
device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable
protection against harmful interference when the equipment is operated in a commercial
environment. This equipment generates, uses and can radiate radio frequency energy and, if not
installed and used in accordance with the instruction manual, may cause harmful interference to radio
communications. Operation of this equipment in a residential area is likely to cause harmful
interference, in which case the user will be required to correct the interference at his own expense.
This device complies with Part 15 of the FCC rules.
Operation is subject to the following two conditions:
(1) This device may not cause harmful interference.
(2) This device must accept any interference that may cause undesired operation.
Warning: Changes or modifications to this unit not expressly approved by the party responsible for
compliance could void the user’s authority to operate the equipment.
Industry Canada
This Class A digital apparatus meets all requirements of the Canadian Interference-Causing
Equipment Regulations.
Cet appareil numerique de la classe A respecte toutes les exigences du Reglement sur le materiel
brouilleur du Canada.
Fax Branding Statement
The Telephone Consumer Protection Act of 1991 makes it unlawful for any person to use a computer
or other electronic device, including fax machines, to send any message unless such message
clearly contains the following information:
 Date and time the message is sent
 Identification of the business or other entity, or other individual sending the message
 Phone number of the sending machine or such business, other entity, or individual
This information is to appear in a margin at the top or bottom of each transmitted page or on the first
page of the transmission. (Adding this information in the margin is referred to as fax branding.)
Since any number of Fax software packages can be used with this product, the user must refer to the
Fax software manual for setup details. Typically, the Fax branding information must be entered via
the configuration menu of the software. 
						

							92 MultiVOIP 400/800 User Guide
FCC Part 68 Telecom
1. This equipment complies with Part 68 of the Federal Communications Commission (FCC) rules.
On the outside surface of this equipment is a label that contains, among other information, the
FCC registration number and ringer equivalence number (REN). If requested, this information
must be provided to the telephone company.
2. As indicated below, the suitable jack (Universal Service Order Code connecting arrangement) for
this equipment is shown. If applicable, the facility interface codes (FIC) and service order codes
(SOC) are shown.  An FCC-compliant telephone cord and modular plug is provided with this
equipment. This equipment is designed to be connected to the telephone network or premises
wiring using a compatible modular jack which is Part 68 compliant. See installation instructions
for details.
3. The ringer equivalence number (REN) is used to determine the number of devices which may be
connected to the telephone line. Excessive REN’s on the telephone line may result in the devices
not ringing in response to an incoming call. In most, but not all areas, the sum of the REN’s
should not exceed five (5.0). To be certain of the number of devices that may be connected to the
line, as determined by the total REN’s, contact the telephone company to determine the
maximum REN for the calling area.
4. If this equipment causes harm to the telephone network, the telephone company will notify you in
advance that temporary discontinuance of service may be required. But if advance notice isn’t
practical, the telephone company will notify the customer as soon as possible. Also, you will be
advised of your right to file a complaint with the FCC if you believe it is necessary.
5. The telephone company may make changes in its facilities, equipment, operations, or procedures
that could affect the operation of the equipment. If this happens, the telephone company will
provide advance notice in order for you to make necessary modifications in order to maintain
uninterrupted service.
6. If trouble is experienced with this equipment (the model of which is indicated below) please
contact Multi-Tech Systems, Inc., at the address shown below for details of how to have repairs
made. If the equipment is causing harm to the telephone network, the telephone company may
request that you remove the equipment from the network until the problem is resolved.
7. No repairs are to be made by you. Repairs are to be made only by Multi-Tech Systems or its
licensees. Unauthorized repairs void registration and warranty.
8. This equipment cannot be used on public coin service provided by the telephone company.
Connection to Party Line Service is subject to state tariffs. (Contact the state public utility
commission, public service commission or corporation commission for information.)
9. If so required, this equipment is hearing-aid compatible.
Manufacturer: Multi-Tech Systems, Inc.
Trade name: MultiVOIP
Model Numbers: MVP400, MVP800
FCC Registration Number: AU7USA-26050-DV-N
Modular Jack (USOC): RJ-11C or RJ-11W
Service Center in U.S.A.: Multi-Tech Systems Inc.
2205 Woodale Drive
Mounds View, MN 55112
(763) 785-3500 Fax (763) 785-9874 
						

							93 Appendix C - Regulatory Information
Canadian Limitations Notice
Ringer Equivalence Number
Notice: The ringer equivalence number (REN) assigned to each terminal device provides an
indication of the maximum number of terminals allowed to be connected to a phone interface. The
termination on an interface may consist of any combination of devices subject only to the requirement
that the sum of the ringer equivalence numbers of all the devices does not exceed 5.
Notice: The Industry Canada label identifies certified equipment. This certification means that the
equipment meets certain telecommunications network protective, operational and safety
requirements. The Department does not guarantee the equipment will operate to the user’s
satisfaction.
Before installing this equipment, users should ensure that it is permissible to be connected to the
facilities of the local telecommunications company. The equipment must also be installed using an
acceptable method of connection. The customer should be aware that compliance with the above
conditions may not prevent degradation of service in some situations. Repairs to certified equipment
should be made by an authorized Canadian maintenance facility designated by the supplier. Any
repairs or alterations made by the user to this equipment, or equipment malfunctions, may give the
telecommunications company cause to request the user to disconnect the equipment.
Users should ensure for their own protection that the electrical ground connections of the power
utility, phone lines and internal metallic water pipe system, if present, are connected together. This
precaution may be particularly important in rural areas.
Caution: Users should not attempt to make such connections themselves, but should contact the
appropriate electric inspection authority, or electrician, as appropriate.
EMC, Safety and Terminal Directive Compliance
The CE mark is affixed to this product to confirm compliance with the following European Community
Directives:
Council Directive 89/336/EEC of 3 May 1989 on the approximation of the laws of Member States
relating to electromagnetic compatibility.
and
Council Directive 73/23/EEC of 19 February 1973 on the harmonization of the laws of Member States
relating to electrical equipment designed for use within certain voltage limits:
and
Council Directive 98/13/EC of 12 March 1998 on the approximation of the laws of Member States
concerning telecommunications terminal and Satellite earth station equipment. 
						

							94 MultiVOIP 400/800 User Guide 
						

							Glossary 
						

							96 MultiVOIP 400/800 User Guide
A
Access:   The T1 line element made up of two pairs of wire that the phone company brings to the customer premises. The Access portion
ends with a connection at the local telco (LEC or RBOC).
Accunet Spectrum of Digital Services (ASDS):   The AT&T 56 Kbps leased (private) line service. Similar to services of MCI and Sprint.
ASDS is available in nx56/64 Kbps, where n=1, 2, 4, 6, 8, 12.
ACK (ACKnowledgement code) (pronounced ack):  A communications code sent from a receiving modem to a transmitting modem to
indicate that it is ready to accept data. It is also used to acknowledge the error-free receipt of transmitted data. Contrast with NAK.
Adaptive Differential Pulse Code (ADCPM): In multimedia applications, a technique in which pulse code modulation samples are
compressed before they are stored on a disk. ADCPM, an extension of the PCM format, is a standard encoding format for storing audio
information in a digital format. It reduced storage requirements by storing differences between successive digital samples rather than full
values.
Address:  A numbered location inside a computer. Its how the computer accesses its resources, like a video card, serial ports,  memory, etc.
AMI line coding:   One of two common methods of T1 line coding (with B8ZS). AMI line coding places restrictions on user data (B8ZS does
not).
Analog signal:    A waveform which has amplitude, frequency and phase, and which takes on a range of values between its maximum and
minimum points.
Analog Transmission:  One of two types of telecommunications which uses an analog signal as a carrier of voice, data, video, etc. An
analog signal becomes a carrier when it is modulated by altering its phase, amplitude and frequency to correspond with the source signal.
Compare with digital transmission.
Application Program Interface (API):  A software module created to allow dissimilar, or incompatible applications programs to transfer
information over a communications link. APIs may be simple or complex; they are commonly required to link PC applications with mainframe
programs.
ASCII (American Standard Code for Information Interchange) (pronounced askey):  A binary code for data that is used in
communications and in many computers and terminals. The code is used to represent numbers, letters, punctuation and control characters.
The basic ASCII code is a 7-bit character set which defines 128 possible characters. The extended ASCII file provides 255 characters.
Asynchronous Transfer Mode (ATM):  A very high-spped method of transmission that uses fixed-size cells of 53 bytes to transfer
information over fiber; also known as cell relay.
AT Commands:  A standard set of commands used to configure various modem parameters, establish connections and disconnect. The AT
is used to get the attention of the modem before the actual command is issued.
Availability:   The measure of the time during which a circuit  is ready for use; the complement of circuit outage (100% minus % outage =
% available).
B
B7ZS (Bipolar 7 Zero Suppression) line coding:  One method of T1 line coding (see also B8ZS and AMI). B7ZS  line coding does not
place restrictions on user data  (AMI does).
B8ZS (Bipolar 8 Zero Suppression) line coding:  One of two common methods of T1 line coding (with AMI). B8ZS  line coding does not
place restrictions on user data  (AMI does). A coding method used to produce 64 Kbps clear transmission. (See also B7ZS and AMI  line
coding)
Backbone:  1. A set of nodes and their interconnecting links providing the primary data path across a network. 2. In a local area network
multiple-bridge ring configuration, a high-speed link to which the rings are connected by means of bridges. A backbone may be configured as
a bus or as a ring. 3. In a wide area network, a high-speed link to which nodes or data switching exchanges (DSEs) are connected. 4. A
common distribution core that provides all electrical power, gases, chemicals, and other services to the sectors of an automated wager
processing system.
Background:  An activity that takes place in the PC while you are running another application. In other words, the active user interface does
not correspond to the background task.
Bandwidth:  The transmission capacity of a computer channel, communications line or bus. It is expressed in cycles per second (hertz), the
bandwidth being the difference between the lowest and highest frequencies transmitted. The range of usable frequencies that a transmission
medium will pass without unacceptable attenuation or distortion. Bandwidth is a factor in determining the amount of information and the
speed at which a medium can transmit data or other information.
Backward Explicit Congestion Notification (BECN):  A bit that tells you that a certain frame on a particular logical connection has
encountered heavy traffic. The bit provides notification that congestion-avoidance procedures should be initiated in the opposite direction of
the received frame. See also FECN (Forward Explicit Congestion Notification).
Basic Rate Interface (BRI):  An ISDN access interface type comprised of two B-channels each at 64 Kbps and one D-channel at 64 Kbps
(2B+D). 
						

							97 Glossary
Bell Operating Companies (BOC): The family of corporations created during the divestiture of AT&T. BOCs are independent companies
which service a specific region of the US. Also called Regional Bell Operating Companies (RBOCs).
Bell Pub 41450:  The Bell publication defining requirements for data format conversion, line conditioning, and termination for direct DDS
connection.
Bell Pub 62310:  The Bell publication defining requirements for data format conversion, line conditioning, and termination for direct DDS
connection.
Binary Synchronous Communication (BSC):  A form of telecommunication line control that uses a standard set of transmission control
characters and control character sequences, for binary synchronous transmission of binary-coded data between stations.
Bit (Binary digIT):  A bit is the basis of the binary number system. It can take the value of  1 or 0. Bits are generally recognized as the
electrical charge generated or stored by a computer that represent some portion of usable information.
Bit Error Rate Test (BERT):A device or routine that measures the quality of data transmission. A known bit pattern is transmitted, and the
errors received are counted and a BER (bit error rate) is calculated. The BER is the ratio of received bits in error relative to the total number
of bits received, expressed in a power of 10.
Bit robbing:  The use of the least significant bit per channel in every sixth frame for signaling. The line signal bits  robbed from the speech
pat conveys sufficient pre-ISDN telephony signaling information with the remaining line signal bits  providing sufficient line signaling bits for
recreating the original sound. See robbed bit signaling.
Blue Alarm:  An error indication signal consisting of all 1s indicating disconnection or attached device failure. Contrast Red Alarm and
Yellow Alarm.
Bps (bits per second):  A unit to measure the speed at which data bits can be transmitted or received. Bps differs from baud when more
than one bit is represented by a single cycle of the carrier.
Bridges:  1. A functional unit that interconnects two local area networks that use the same logical link protocol but may use different medium
access control protocols. 2. A functional unit that interconnects multiple LANs (locally or remotely) that use the same logical link control
protocol but that can use different medium access control protocols. A bridge forwards a frame to another bridge based on the medium
access control (MAC) address. 3. In the connection of local loops, channels, or rings, the equipment and techniques used to match circuits
and to facilitate accurate data transmission.
Buffer:  A temporary storage register or Random Access Memory (RAM) used in all aspects of data communications which prevents data
from being lost due to differences in transmission speed. Keyboards, serial ports, muxes and printers are a few examples of the devices that
contain buffers.
Bus:  A common channel between hardware devices either internally between components in a computer, or externally between stations in a
communications network.
Byte:  The unit of information a computer can handle at one time. The most common understanding is that a byte consists of  8 binary digits
(bits), because thats what computers  can handle. A byte holds the equivalent of a single character (such as the letter A).
C
Call Setup Time:  The time to establish a circuit-switched call between two points. Includes dialing, wait time, and CO/long distance service
movement time.
Carrier Group Alarm (CGA):  A T1 service alarm generated by a channel bank when an OOF condition occurs for a predefined length of
time (usually 300mS to 2.5 seconds). The CGA causes the calls using a trunk to be dropped and for trunk conditioning to be applied.
Carrier signal:  An analog signal with known frequency, amplitude and phase characteristics used as a transport facility for useful
information. By knowing the original characteristics, a receiver can interpret any changes as modulations, and thereby recover the
information.
CCITT (Consultative Committee for International Telephone and Telegraph):  An advisory committee created and controlled by the
United Nations and headquartered in Geneva  whose purpose is to develop and to publish recommendations for worldwide standardization of
telecommunications devices. CCITT has developed modem standards that are adapted primarily by PTT (post, telephone and telegraph)
organizations that operate telephone networks of countries outside of the U.S. See also ITU.
Central Office (CO):  The lowest, or most basic level of switching in the PSTN (public switched telephone network). A business PABX or any
residential phone connects to the PSTN at a central office.
Centrex:  A multi-line service offered by operating telcos which provides, from the telco CO, functions and features comparable to those of a
PBX for large business users. See also Private Branch Exchange, Exchange.
Channel:  A data communications path between two computer devices. Can refer to a physical medium (e.g., UTP or coax), or to a specific
carrier frequency.
Channel bank:  A device that acts as a converter, taking the digital signal from the T1 line into a phone system and converting it to the
analog signals used by the phone system. A channel bank acts as a multiplexer, placing many slow-speed voice or data transactions on a
single high-speed link. 
						

							98 MultiVOIP 400/800 User Guide
Circuit-switched Network:  A technology used by the PSTN that allocates a pair of conductors for the exclusive use of one communication
path. Circuit switching allows multiple conversations on one talk path only if the end-users multiplex the signals prior to transmission.
Circuit switching:  The temporary connection of two or more communications channels using a fixed, non-shareable path through the
network. Users have full use of the circuit until the connection is terminated.
Clear Channel:   A transmission path where the full bandwidth is used (i.e., no bandwidth needed for signaling, carrier framing or control
bits). A 64 Kbps digital circuit usually has 8 Kbps used for signaling. ISDN has two 64 Kbps circuits, and a 16 Kbps packet service of which
part is used for signaling on the 64K channels.
Client-Server:  In TCP/IP, the model of interaction in distributed data processing in which a program at one site sends a request to a program
at another site and awaits a response. The requesting program is called a client; the answering program is called a server.
Cluster Controller:  A device that can control the input/output operations of more than one device connected to it. A cluster controller may be
controlled by a program stored and executed in the unit, or it may be entirely controlled by hardware.
CODEC (COmpression/DEcompression): The term is used to describe the conversion of voice signals from their analog form to digital
signals acceptable to modern digital PBXs and digital transmission systems. It then converts those digital signals back to analog so that you
can hear and understand what the other person is saying. In some phone systems, the CODEC is in the PBX and shared by many analog
phone extensions. In other phone systems, the CODEC is actually in the phone. Thus the phone itself sends out a digital signal and can, as a
result, be more easily designed to accept a digital RS-232-C signal.
Committed Burst Size: The maximum number of bits that the frame relay network agrees to transfer during any measurement interval
Committed Information Rate (CIR):  An agreement a customer makes to use a certain minimum data transmission rate (in bps). The CIR is
part of the frame relay service monthly billing, along with actual usage, that users pay to their frame relay service provider.
Compression: 1. The process of eliminating gaps, empty fields, redundancies, and unnecessary data to shorten the length of records or
blocks. 2. In SNA, the replacement of a string of up to 64-repeated characters by an encoded control byte to reduce the length of the data
stream to the LU-LU session partner. The encoded control byte is followed by the character that was repeated (unless that character is the
prime compression character). 3. In Data Facility Hierarchical Storage Manager, the process of moving data instead of allocated space during
migration and recall in order to release unused space. 4. Contrast with decompression.
COMx Port:  A serial communications port on a PC.
Congestion:   A network condition where there is too much data traffic. The ITU I.233 standard defines congestion management in terms of
speed and burstiness.
Congestion notification:   The function in frame relay that ensures that user data transmitted at a rate higher than the CIR are allowed to
slow down to the rate of the available network bandwidth.
Consecutive Severely Errored Seconds (CSES):  An error condition that occurs when from 3 to 9 SES (Severely Errored Seconds) are
logged consecutively.
Customer Premise Equipment (CPE):  The generic term for data comm and/or terminal equipment that resides at the user site and is
owned by the user with the following exclusions: Over voltage protection equipment, inside wiring, coin operated or pay telephones,
company-official equipment, mobile phone equipment, 911 equipment, equipment necessary for the provision of communications for
national defense, or multiplexing equipment used to deliver multiple channels to the customer.
D
D4:  the T1 4th generation channel bank.
D4 channelization:  Refers to the compliance with AT&T TR 62411 for DS1 frame layout.
D4 framing:  The T1 format for framing in AT&T D-Series channel banks, in which there are 12 separate 193-bit frames in a super-frame. A
D4 framing bit is used to identify the channel and the signaling frame. Signalling for voice channels is carried in-band for every channel, along
with the encoded voice.  See robbed-bit signaling.
Data Communications Equipment (DCE):  Any device which serves as the portal of entry from the user equipment to a telecommunications
facility. A modem is a DCE for the phone network (PSTN) that is commonly on site at the user’s premises. Packet Switched Networks have
another level of DCE which is most often located at a central office.
Data Link Connection Identifier (DLCI):  One of the six components of a frame relay frame. Its purpose is to distinguish separate virtual
circuits across each access connection. Data coming into a frame relay node is thus allowed to be sent across the interface to the specified
address. The DLCI is confirmed and relayed to its destination, or if the specification is in error, the frame is discarded.
Dataphone Digital Service (DDS):  A private line digital service that offers 2400, 4800, 9600 and 56 Kbps data rates on an inter-LATA basis
by AT&T and on an intra-LATA basis by the BOCs.
Data Service Unit (DSU):  A device that provides a digital data service interface directly to the data terminal equipment. The DSU provides
loop equalization, remote and local testing capabilities, and a standard EIA/CCITT interface.
Dedicated Line:  A communication line that is not switched. The term leased line is more common.
Default:  This is a preset value or option in software packages, or in hardware configuration, that is used unless you specify otherwise. 
						

							99 Glossary
Device driver:  Software that controls how a computer communicates with a device, such as a printer or mouse.
Digital Cross-connect System (DCS):The CO device which splits and redistributes the T1 bandwidth. the DCS takes time slots from
various T1 lines and alters them to provide the needed connectivity. DCS connections are made with software at an administrators
workstation.
Digital Data:  Information represented by discrete values or conditions (contrast Analog Data).
Digital Loopback:  A technique used for testing the circuitry of a communications device. Can be initiated locally, or remotely (via a
telecommunications device). The tested device decodes and encodes a  received test message, then echoes the message back. The results
are compared with the original message to determine if corruption occurred en route.
Digital PBX:  A Private Branch Exchange that operates internally on digital signals. See also Exchange.
Digital Service, level 0  (DS0):   The world-wide standard speed (64 Kbps) for digital voice conversation using PCM (pulse coded
modulation).
Digital Service, level 1 (DS1):  The 1.544 Mbps voice standard (derived from an older Bell System standard) for digitized voice transmission
in North America. The 1.544 Mbps consists of 24 digitally-encoded 64 Kbps voice channels (north America) and 2.048 Mbps (30 channels)
elsewhere.
Digital Signal:  A discrete or discontinuous signal (e.g., a sequence of voltage pulses). Digital devices, such as terminals and computers,
transmit data as a series of electrical pulses which have discrete jumps rather than gradual changes.
Digital Signaling Rates (DSn):  A hierarchical system for transmission rates, where DS0 is 64 Kbps (equivalent to ISDN B channel), and
DS1 is 1.5 Mbps (equivalent to ISDN PRI).
Digital Transmission:  A method of electronic information transmission common between computers and other digital devices. Analog
signals are waveforms: a combination of many possible voltages. A computers digital signal may be only high or low at any given time.
Therefore, digital signals may be cleaned up (noise and distortion removed) and amplified during transmission.
Digitize:  To convert an analog signal to a digital signal.
DIP switch (pronounced dip switch):  A set of tiny toggle switches, built into a DIP (dual in-line package), used for setting configurable
parameters on a PCB (printed circuit board).
Driver:  A software module that interfaces between the Operating System and a specific hardware device (i.e. color monitors, printers, hard
disks, etc.). Also known as a device driver.
Drop and Insert:  The process where  a portion of information carried in a transmission system is demodulated (Dropped) at an
intermediate point and different information is included (Inserted) for subsequent transmission.
DTE (Data Terminating Equipment):  A term used to include any device in a network which generates, stores or displays user information.
DTE is a telecommunications term which usually refers to PCs, terminals, printers, etc.
DTMF (Dual-Tone MultiFrequency):  A generic push-button concept made popular by AT&T TouchTone.
E
E&M:   A telephony trunking system used for either switch-to-switch, or switch-to-network, or computer/telephone system-to-switch
connection.
EIA:  The Electronics Industries Association is a trade organization in Washington, DC that sets standard for use of its member companies.
(See RS-232, RS-422, RS530.)
Encapsulation:  A technique used by network-layer protocols in which a layer adds header information to the protocol data unit from the
preceding layer. Also used in enveloping one protocol inside another for transmission. For example, IP inside IPX.
Endpoint: The clients in an H.323 network. They are typically video conferencing, audio conferencing, or other multimedia systems
implemented by end users to communicate in real time. The H.323 standard requires that every endpoint support certain functions and
codecs (Coder/Decoder) that have previously been defined by the ITU.
Errored Seconds (ES):  Any second of operation that all 1.544M bits are not received exactly as transmitted. Contrast Error Free Seconds.
Error Free Seconds (EFS):  Any second of operation that all 1.544M bits are received exactly as transmitted. Contrast Errored Seconds.
ESF Error Event:  A T1 error condition that is logged when a CRC-6 error or an OOF error occurs.
Ethernet:  A 10-megabit baseband local area network that allows multiple stations to access the transmission medium at will without prior
coordination, avoids contention by using carrier sense and deference, and resolves contention by using collision detection and transmission.
Ethernet uses carrier sense multiple access with collision detection (CSMA/CD).
Excess Zeros:  A  T1 error condition that is logged when more than 15 consecutive 0s  or less than one 1 bit in 16 bits occurs.
Exchange:  A unit (public or private) that can consist  of one or more central offices established to serve a specified area. An exchange
typically has a single rate of charges (tariffs) that has previously been approved by a regulatory group. 
						

							100 MultiVOIP 400/800 User Guide
Exchange Area:  A geographical area with a single uniform  set of charges (tariffs), approved by a regulatory group, for phone services. Calls
between any two points within an exchange area are local calls. See also Digital PBX, PBX.
Exchange Termination (ET):  The carriers local exchange switch. Contrast with Loop Termination - LT.
Explicit Congestion Management:  The method used in frame relay to notify the terminal equipment that the network is overly busy. The
use of FECN and BECN is called explicit congestion management. Some end-to-end protocols use FECN or BECN, but usually not  both
options together. With this method, a congestion condition is identified and fixed before it becomes critical. Contrast with implicit congestion.
Extended Super Frame (ESF):  One of two popular formats for framing bits on a T1 line. ESF framing has a 24-frame super-frame, where
robbed bit signaling is inserted in the LSB (bit 8 of the DS-0 byte) of frames 6, 12, 18 and 24. ESF has more T1 error measurement
capabilities than D4 framing. ESF and B8ZS are typically both offered to provide clear channel service.
F
Failed Seconds:  A test parameter where the circuit is unavailable for one full second.
Failed Signal:  A T1 test parameter logged when there are more than 9 SES (Severely Errored Seconds).
Fax (facsimile):  Refers to the bit-mapped rendition of a graphics-oriented document (fax) or to the electronic transmission of the image over
phone lines (faxing). Fax transmission differs from data transmission in that the former is a bit-mapped approximation of a graphical
document and, therefore, cannot be accurately interpreted according to any character code.
Firmware:  A category of memory chips that hold their content without electrical power, they include ROM, PROM, EPROM and EEPROM
technologies. Firmware becomes hard software when holding program code.
Foreground:  The application program currently running on and in control of the PC screen and keyboard. The area of the screen that
occupies the active window. Compare with background.
Fractional T1 (FT1):  A digital data transmission rate between 56 Kbps (DS0 rate) and 1.544 Mbps (the full T1 rate - in North America). FT1
is typically provided on 4-wire (two copper pairs) UTP. Often used for video conferencing, imaging and LAN interconnection due to its low cost
and relatively high speed. FT1 rates are offered in 64 Kbps multiples, usually up to 768 Kbps.
Frequency:  A characteristic of an electrical or electronic signal which describes the periodic recurrence of cycles. Frequency is inversely
proportional to the wavelength or pulse width of the signal (i.e., long wavelength signals have low frequencies and short wavelength signals
yield high frequencies).
Foreign Exchange (FX):  A CO trunk with access to a distant CO, allowing ease of access and  flat-rate calls anywhere in the foreign
exchange area.
Foreign Exchange Office (FXO):  provides local phone service from a CO outside of  (foreign to) the subscribers exchange area. In simple
form, a user can pick up the phone in one city and receive a tone in the foreign city.
Connecting a POTS phone to a computer telephony system via a T1 link requires a  channel bank configured for the FX connection. To
generate a call from the POTS set to the computer telephony system, an  FXO connection must be configured.
Foreign Exchange Station (FXS):  See FX, FXO. To generate a call from the computer telephony system to the POTS set, a  FXS
connection must be configured.
Forward Explicit Congestion Notification (FECN):  A bit that tells you that a certain frame on a particular logical connection has
encountered heavy traffic. The bit provides notification that congestion-avoidance procedures should be initiated in the same direction of the
received frame. See also BECN (Backward Explicit Congestion Notification).
Frame:  A group of data bits in a specific format to help network equipment recognize what the bits mean and how to process them. The bits
are sent serially, with a flag at each end signifying the start and end of the frame.
Frame Relay:  A form of packet switching that uses small packets and that requires less error checking than other forms of packet switching.
Frame relay is effective for sending bursty data at high speeds (56/64K, 256K, and 1024 Kbps) over wide area networks. Frame Relay
specifications are defined by ANSI documents ANSI T1.602, T1.606, T1S1/90-175, T1S1/90-213, and T1S1/90-214. In using frame relay,
blocks of information (frames) are passed across a digital network interface using a connection number that is applied to each frame to
distinguish between individual frames.
Frame Relay Forum:  A non-profit organization of 300+ vendors and service providers, based in Foster City, CA, that are developing and
deploying frame relay equipment.
Frame Relay Implementors Forum:   A group of companies supporting a common specification for frame relay connection to link customer
premises equipment to telco network equipment. Their specification supports ANSI  frame relay specs and defines extensions such as local
management.
Frame Relay Access Device (FRAD):  A piece of equipment that acts as a concentrator or frame assembler/dissassembler that can support
multiple protocols and provide basic routing functions.