Terme générique qui désigne non seulement un fournisseur d'accès InternetIAP) mais aussi le plus souvent un organisme qui fournit en plus des services.(ISP). Les deux notions étant confondues en une seule.
A list of the most common questions and their responses posted on a newsgroup.
Document rassemblant les questions les plus souvent posées sur un thème particulier. A l'origine ces documents sont "postés" dans les forums de news Usenet. Ces documents sont publiés avec une périodicité le plus souvent d'un mois. Un site où retrouver les faqs: http://www.landfield.com/faqs/.
Any mathematical formula which derives a numeric value based on the bit pattern of a transmitted block of information and uses that value at the receiving end to determine the existence of any transmission errors.
An ANSI-defined standard for implementing a high-speed (100 Mbps) LANover fiber.FDDI is a fault-tolerant dual counter-rotating-ring design.
The simultaneous transmission of multiple separate signals through a shared medium (such as a wire, {optical fibre} or light beam) by modulating, at the transmitter, the separate signals into separable frequency bands, and adding those results linearly either before transmission or within the medium. While thus combined, all the signals may be amplified, conducted, translated in frequency and routed toward a destination as a single signal, resulting in economies which are the motivation for multiplexing. Apparatus at the reciever separates the multiplexed signals by means of frequency passing or rejecting filters, and demodulates the results individually, each in the manner appropriate for the modulation scheme used for that band or group.
Bands are joined to form groups, and groups may then be joined into larger groups; this process may be considered recursively, but such technique is common only in large and sophisticated systems and is not a necessary part of FDM.
Neither the transmitters nor the recievers need be close to each other; ordinary radio, television, and cable service are examples of FDM. It was once the mainstay of the long distance telephone system. The more recently developed {time division multiplexing} in its several forms lends itself to the handling of digital data, but the low cost and high quality of available FDM equipment, especially that intended for television signals, make it a reasonable choice for many purposes.
(08 Mar 1995)
A technique that allows for the channel bandwidth of a circuit to be subdivided into many little channels (one per traffic stream).
Voir AMRF.
An error correction technique where there are no retransmissions and therefore the receiver is responsible for correcting any errors in the packets. FEC takes advantage of the sequence number contained in an ATM AAL (ATM adaptation layer) 1 protocol data unit to detect cell loss and prevent unnecessary transmission of cells belonging to faulty packets. A recent proposal to the ATM Forum advocates the use of FEC to address problems of data loss and packet delay on shared constant bit rate ATM links. According to studies conducted by several ATM Forum member companies, using FEC to detect cell loss allows multiple ATM devices to share the same virtual circuit for real-time audio and video transmission with minimal added overhead (approximately 3 percent) and only slight performance degradation.
A bit in the frame relay header. The bit is set by a congested network node in any frame which is traveling in the same direction as the congestion. (In frame relay, a node can be congested in one direction of frame flow but not in the other.) (see BECN, EFCI).
A protocol, defined in RFC 1288, that allows information about a system or user on a system to be retrieved.
Finger also refers to the commonly used Internet software tool for locating people on other Internet sites.
Finger is also sometimes used to give access to non-personal information, but the most common use is to see if a person has an account at a particular Internet site. Some sites consider finger to be a security risk and have either disabled it, or replaced it with a simple message.
C'est aussi un utilitaire logiciel permettant de trouver l'adresse et certaines informations concernant un correspondant connecté sur un site Internet. Il faut au minimum connaître le nom du site sur lequel cette personne travaille. Lorsque l'on lance Finger sur un site quelconque, la liste de toutes les personnes connectées à ce site est retournée. Pour des raisons de sécurité, il se peut que le service soit interdit sur un site ou remplacé par un simple message.
A queue. A data structure or hardware buffer from which items are taken out in the same order they were put in. Also known as a "shelf" from the analogy with pushing items onto one end of a shelf so that they fall off the other. A FIFO is useful for buffering a stream of data between a sender and receiver which are not synchronised - i.e. not sending and receiving at exactly the same rate. Obviously if the rates differ by too much in one direction for too long then the FIFO will become either full (blocking the sender) or empty (blocking the receiver). A Unix pipe is a common example of a FIFO.
The opposite of a FIFO is a LIFO (last in first out) which is the same as a stack.
Fiber-optic signaling methodology based on the IEEE 802.3 fiber-optic specification.
- rate-based control, where the rate at which the source can transmit is monitored and controlled,
- credit-based control, where a source can transmit a cell if there is a credit available. CAC is also part of the flow control. See alsoCongestion control.
Ensemble de méthodes utilisées en réseaux pour la régulation du trafic et éviter la congestion. Il existe trois techniques:
- le contrôle basé sur un mécanisme à "fenêtre", où une fenêtre glissante st utilisée pour déterminer combien de cellules ont été transmises durant une période prédéfinie,
- le contrôle basé sur les taux, où le taux auquel la source peut transmettre est surveillé et contrôlé,
- le contrôle basé sur un mécanisme de "crédits", où la source peut transmettre une cellule seulement si elle dispose d'un crédit(jeton) pour le faire.CAC est un mécanisme de contrôle de flux.
A fiber optic signaling method based on the IEEE 802.3 and implemented over two fiber links, transmit and receive, in a point-to-point link. This medium may be up to 500m and 1 kilometer(3,280 ft.) long depending on the number of repeaters in the network.
It has been replaced by 10BASE-FL.
Spécification pour méthode de signalisation pour liaison fibre optique basée sur IEEE 802.3 et implémentée sur deux liaisons fibre optique, émission et réception dans une liaison point à point. Le but est l'interconnexion de 2 répéteurs dans un réseau éthernet standard. Les deux répéteurs comptent pour 1. Distance max. 1000m.
FOIRL a été remplacé par 10BASE-FL.
A datalink layer "packet" which contains the header and trailer information required by the physical medium. That is, network layer packets are encapsulated to become frames. See also datagram, encapsulation, packet. (language implementation) See activation record. One complete scan of the active area of a display screen. Each frame consists of a number N of horizontal scan lines, each of which, on a computer display, consists of a number M of pixels. N is the vertical resolution of the display and M is the horizontal resolution. The rate at which the displayed image is updated is the refresh rate in frames per second.
Suite définie d'informations constituant une entité logique de base pour la transmission dans un réseau. Une trame comporte les informations à transmettre proprement dites et des informations de contrôle qui les précèdent et les suivent.
A packet-switching technology to provide a very reliable packet delivery over virtual circuits (VC). Some of the concepts used in frame relay have been incorporated in ATM networks.
Technologie de commutation de paquets rapide appelée aussi relayage de trame qui consiste à opérer un multiplexage au niveau de la couche 2 du modèle OSI. Sorte de X25 allégé. Un certain nombre de concepts utilisé par le relayage de trame ont étéincorporés dans les réseaux ATM.
DMTF site: http://www.frforum.com/
Le site de DMTF: http://www.frforum.com/.
Qualificatif des logiciels que l'on peut librement utiliser gratuitement Ces logiciels sont diffusés gratuitement (via internet, cdrom de compilation) et peuvent être copiés légalement dans un but non commercial. A la différence des logiciels du domaine public l'auteur se réserve la propriété, le progamme "source" n'étant pas modifiable.
A form of network management for allocating resources (buffers, bandwidth) dynamically.
A (TCP/IP) Internet application and protocol used for transferring files between different machines across a network over TCP/IP services.
Protocole de transfert de fichiers fonctionnant sur les protocoles TCP/IP.
See Anonymous FTP.
Voir duplex.
A subseries of RFCs that are not technical standards or descriptions of protocols. FYIs convey general information about topics related to TCP/IP or the Internet.
See also STD.