F

FAQ Frequently Asked Questions - a help document that contains answers to frequently asked questions.

FAT File Allocation Table - the DOS filesystem.

Fast Ethernet A 100-Mbps technology based on the 10BASE-T Ethernet CSMA/CD network access method.

Fault tolerance Generally, the ability to prevent a problem on a device from affecting other devices on the same port.

FCM FDDI concentrator module

FCS (Frame Check Sequence; First Customer Shipment) Extra characters added to a frame for error control purposes; HDLC term adopted by subsequent link layer protocols.

FC S First Customer Ship date. The released final product shipped to the 3Com sales channel.

FDDI (Fiber-Optic Distributed Data Interface; Fiber Distributed Data Interface) LAN technology that permits 100-megabit-per-second (Mbps) data transfer. ANSI has proposed FDDI as standard X3T9.5.

FEA Fast Ethernet Alliance

FEAM FDDI enterprise access module

FECN Forward Explicit Congestion Notification

FEP (Front-End Processor) Device or board that provides a network interface for networked devices. In SNA, typically an IBM 3745 device.

Fiber-optic cable A transmission medium that uses glass or plastic fibers, rather than copper wire, to transport data or voice signals. The signal is imposed on the fibers via pulses (modulation) of light from a laser or a light-emitting diode (LED). Because of its high bandwidth and lack of susceptibility to interference, fiber-optic cable is used in long-haul or noisy applications.

File Server (See Server) A machine on a network whose sole purpose is to centrally store application software and user data.

Finger A service that responds to queries and retrieves user information remotely.

Firewall A router or workstation with multiple network interfaces that controls and limits specific protocols, types of traffic within each protocol, types of services, and direction of the flow of information.

Flash EPROM PROM (Programmable Read-Only Memory) technology providing nonvolatile storage that can be electrically erased in the circuit and reprogrammed; developed by Intel and licensed to other semiconductor companies.

Flooding Technique where routing information received by a routing device is sent out through every interface on that device except the one on which the information was received.

Flow control Method for ensuring that a transmitting entity does not overwhelm a receiving entity with data.

FLP Fast link pulse

FMS Flexible Media Stack products from 3Com

FOIRL (Fiber Optic Inter-Repeater Link) Fiber-optic signalling methodology based on the IEEE 802.3 fiber-optic specification.

FQDN Fully Qualified Domain Name - the full DNS address of a machine including all the the domains it resides in (including the "root" domain which is signified by a final dot ".").

Fractional T-1 A WAN communications service that provides the user with some portion of a T1 circuit which has been divided into 24 separate 64 Kb channels; Fractional E-1 in Europe.

Fragment A piece of a larger packet that has been broken down into smaller units.

Fragmentation Breaking a packet into smaller units when transmitting over a network medium that cannot support the original size of the packet.

Frame Set of bits that form an elementary block of data to be sent over a communications channel. Usually, a frame contains its own control information, including the transmission address and data for error detection.

Frame Relay A packet-switching wide-area technology for interconnecting LANs at high speeds. Frame relay defines the interface between user equipment and a WAN; it does not define internal operation of the network or the interfaces or protocols used within the WAN itself. For this reason, the term "frame- relay cloud" is often used to describe the internal operation of a WAN that has a frame-relay interface.

FSP File Service Protocol

FTAM (File Transfer, Access and Management) The OSI remote file service and protocol. See FTP.

FTP (File Transfer Protocol) (TCP/IP) The Internet application and protocol used to send complete files over TCP/IP services.

Full duplex The ability of a device or line to transmit data simultaneously in both directions.

Full-Duplex Token Ring Part of the 802.5 standard that defines dedicated and full-duplex communication for Token Ring networks at speeds of 32 Mbps.

Functional grouping Placing all users performing the same function, and the servers they require, on the same ring.

FUNI Frame-based UNI