Network Protocols & Communications (Part 1)

00:12:25
https://www.youtube.com/watch?v=ly8ikWtAY7s

Summary

TLDRCette vidéo introduit les concepts clés des protocoles réseaux et de la communication de données. Elle commence par expliquer le rôle fondamental des protocoles dans les réseaux informatiques, qui sont des ensembles de règles permettant une communication efficace et compréhensible entre les appareils. Les différents modes de flux de données sont abordés : - Le mode simplex qui supporte la communication unidirectionnelle, comme un clavier vers un ordinateur. - Le mode half-duplex qui permet une communication bidirectionnelle non simultanée, tel qu’un walkie-talkie. - Le mode full-duplex offrant une communication bidirectionnelle simultanée, exemplifié par les lignes téléphoniques. Ensuite, les éléments essentiels des protocoles, tels que l'encodage, le formatage, l’encapsulation, le timing et la taille des messages sont discutés. Ces éléments garantissent que les messages sont correctement codés pour le transfert à travers les différents médiums, qu’ils soient filaires ou sans fil. De plus, la vidéo couvre les options de livraison, à savoir l’unicasting, le multicasting et le broadcasting, permettant d'adapter la diffusion des messages selon le public cible. Enfin, l'importance des protocoles dans l'assurance d'une communication sans heurts, même avec des capacités de lien variables, est soulignée. Ce contenu est crucial pour ceux qui cherchent à comprendre le fonctionnement des réseaux informatiques.

Takeaways

  • 🔄 Compréhension des flux de données simplex, half-duplex, et full-duplex.
  • 📡 Importance des protocoles dans les réseaux informatiques.
  • 📝 Protocole comme ensemble de règles pour une communication efficace.
  • ⚙️ Encodage et formatage comme éléments clés des protocoles.
  • ⚖️ Gestion de la taille des messages et du timing pour l'efficacité.
  • 📬 Différentes options de livraison des messages: unicast, multicast, broadcast.
  • 🚦 Rôle crucial des protocoles pour éviter le chaos communicationnel.
  • 🔄 Comparaison entre les communications humaines et en réseau.
  • 🔧 Adaptation aux médiums de transmission: filaire vs sans fil.
  • 📏 Importance du redimensionnement des messages selon les capacités du réseau.

Timeline

  • 00:00:00 - 00:05:00

    Dans cette première partie, le cours aborde les protocoles et la communication réseau. Il explique d'abord ce qu'est la communication de données, qui est l'échange d'informations entre deux nœuds via un médium de transmission comme un câble. Ensuite, le concept de flux de données est examiné, identifiant trois types de flux de données: simplex (unidirectionnel comme le clavier au CPU), semi-duplex (bidirectionnel mais pas simultané, comme un talkie-walkie), et duplex intégral (simultané, comme une ligne téléphonique). On aborde aussi la nécessité des protocoles, qui sont des règles régissant la communication afin d'éviter le chaos, illustrées par des scénarios où l'absence de protocole rend la communication inefficace.

  • 00:05:00 - 00:12:25

    La deuxième partie se concentre sur les protocoles dans la communication humaine et réseau, soulignant l'importance des éléments comme l'encodage des messages, le formatage et l'encapsulation, la taille et le timing des messages, et les options de livraison. On explique que pour une communication efficace, le message doit être correctement encodé et les protocoles assurent que le message est transmis et reçu correctement, aussi bien en termes de réponse dans un délai donné qu'en termes de contrôle de flux pour éviter la surcharge du récepteur. Enfin, le cours couvre les différentes options de livraison : unicast, multicast et broadcast, et insiste sur l'importance des protocoles pour garantir une communication sans faille et précise en réseau.

Mind Map

Mind Map

Frequently Asked Question

  • Qu'est-ce que la communication de données ?

    La communication de données est l'échange d'informations entre deux nœuds via un lien ou un média de transmission.

  • Quels sont les trois types de flux de données ?

    Les trois types de flux de données sont simplex, half-duplex, et full-duplex.

  • Qu'est-ce qu'un flux simplex ?

    Un flux simplex est une communication unidirectionnelle où l'un des nœuds transmet et l'autre reçoit.

  • Comment fonctionne un flux half-duplex ?

    Dans un flux half-duplex, la communication peut se faire dans les deux sens, mais pas simultanément.

  • Qu'est-ce qu'un flux full-duplex ?

    Dans un flux full-duplex, la communication peut se faire dans les deux sens simultanément.

  • Qu'est-ce qu'un protocole en réseau ?

    Un protocole est un ensemble de règles qui régissent la communication de données dans un réseau.

  • Pourquoi les protocoles sont-ils importants en communication réseau ?

    Les protocoles établissent des règles pour assurer que les données sont échangées de manière compréhensible, efficace et fluide entre les appareils.

  • Quels sont les éléments d'un protocole ?

    Les éléments d'un protocole incluent l'encodage, le formatage, et l'encapsulation des messages, ainsi que le timing, la taille des messages, et les options de livraison.

  • Qu'est-ce que le message formatting en termes de protocole ?

    Le formatage des messages implique le formatage des données de manière convenue entre l'émetteur et le récepteur pour assurer une compréhension mutuelle.

  • Quels sont les types d'options de livraison ?

    Les types d'options de livraison incluent unicasting, multicasting, et broadcasting.

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  • 00:00:00
    hello everyone welcome back to the
  • 00:00:02
    course on computer networks today we
  • 00:00:04
    shall see Network protocols and
  • 00:00:06
    communication before we step into the
  • 00:00:08
    topic we shall understand what are the
  • 00:00:10
    things we are going to learn today today
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    we will be learning about data
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    communication data flow what are the
  • 00:00:17
    importance of protocol in computer
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    network understand guys protocols are
  • 00:00:22
    very important in computer network and
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    what are the elements will also be
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    addressed in today's session now we
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    shall see what is data communication
  • 00:00:30
    data communications are the exchange of
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    data between two nodes if there are two
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    nodes they are going to exchange data
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    via some form of link or transmission
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    medium in this case the transmission
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    medium is the cable we have seen data
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    communication it means two nodes are
  • 00:00:50
    going to exchange data data flow means
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    the data is going to flow from one node
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    to another node and there are three
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    different flows simplex half-duplex full
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    duplex we shall see all these three data
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    flows in detail firstly the simplex it
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    is always a unidirectional communication
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    one node can transmit and other will
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    receive for example keyboards just take
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    a keyboard is connected to a CPU
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    keyboard is going to give data to the
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    CPU whereas CPU is not going to give any
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    data to the keyboard likewise our
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    traditional monitors I am NOT talking
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    about our touch monitors are traditional
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    monitors whatever the data is there in
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    the CPU that is going to be given to the
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    monitor and monitor is not going to give
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    any information to the CPU in both the
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    cases the data or the communication is
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    always unidirectional coming to the half
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    duplex the communication is in both
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    directions it means it can send as well
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    as it can receive but not at the same
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    time the very important part about half
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    duplex is that the communication can
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    happen in both directions but not at the
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    same time if one device is sending the
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    other device can receive and not at the
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    same time both sending and receiving can
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    happen example walkie talkie in a walkie
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    talkie we can talk as well as we can
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    but we can't talk and listen at the same
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    time now we shall see what is
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    full-duplex or simply duplex in the
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    previous case that is the half duplex
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    communication happened in both
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    directions but not at the same time
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    whereas in full duplex communication can
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    happen in both directions simultaneously
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    it means devices can send or receive
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    data at the same time example telephone
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    line we can talk as well as listen
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    simultaneously in a telephone line now
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    we shall see an example for simplex
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    communication now this computer is
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    sending data in only one direction so
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    this is simplex if both sending and
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    receiving can happen but not at the same
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    time if you observe now sending is
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    happening now receiving is happening but
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    not at the same time this is sending and
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    this is receiving this is not happening
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    at the same time so this comes under
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    half-duplex and full-duplex mode of
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    communication both sending and receiving
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    can happen at the same time if both
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    sending and receiving can happen
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    simultaneously then we call as full
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    duplex we will now see what are
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    protocols any communication scheme
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    whether it is a postal communication or
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    a whatsapp communication or SMS way of
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    communication we always have certain
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    things in common they are source or
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    sender destination or the receiver
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    Channel or media any communication will
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    definitely have these things source or
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    the sender destination or the receiver
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    channel or the media and this
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    communication will always be governed by
  • 00:03:51
    certain protocols so protocols are rules
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    that governs all the methods of
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    communication what if there are no
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    protocols if this guy speaks at high
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    speed which this destination cannot
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    handle this communication becomes
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    useless so they have to mutually agree
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    upon certain rules what if this blue guy
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    speaks in the language which this guy
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    cannot understand
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    he may be grammatically correct but
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    still there is no use in this
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    communication again what if this blue
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    guy keeps on talking at a high speed at
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    the same time not at all giving any room
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    for this guy to respond so these are
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    example situations where the
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    communication goes chaos or messy so
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    definitely there is a need for protocols
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    because a protocol is a set of rules
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    that governs data communication simply
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    speaking protocol is a rule that governs
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    data communication protocol determines
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    what is communicated in the network how
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    it is communicated in the network and
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    when it is communicated in the network
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    before going into the network
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    communication let's talk about the
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    protocols in the human communication in
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    human communication definitely there
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    should be sender and a receiver there
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    may be a single receiver or a group of
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    receivers and this human communication
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    can be effective only when this
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    communication involves common language
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    and grammar otherwise communication will
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    not be perfect and speed and timing of
  • 00:05:21
    delivery of speech is also very
  • 00:05:23
    important in human communication and if
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    this guy wants to ensure whatever he has
  • 00:05:27
    talked is understandable by this guy he
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    should get confirmation or the
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    acknowledgement from the receiver that
  • 00:05:33
    is the destination only then human
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    communication can be effective we have
  • 00:05:38
    just seen what is human communication
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    why do we need protocols in human
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    communication now we shall see why do we
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    need protocols in network communication
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    say if there is a sender and there is a
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    receiver and this communication can be
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    effective when these protocols are
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    addressed properly the message should be
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    encoded formatted and encapsulated in
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    such a way that the destination can
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    understand timing is also very important
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    in network communication the size is
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    also very important because the link
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    cannot carry big data if this is a low
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    capacity link then this link cannot
  • 00:06:13
    carry big data if there is a very big
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    data in the sender side
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    it cannot send that big data on a very
  • 00:06:19
    small link so it has to be handled
  • 00:06:21
    appropriately at the same time the
  • 00:06:24
    delivery option should also be dealt
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    whether the message is only for one
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    destination or some group of
  • 00:06:29
    destinations on all the day
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    nations in the network that should also
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    be dealt in the protocol spot so a
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    protocol defines message encoding
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    message formatting and encapsulation
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    message timing message size and the
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    delivery that is what we exactly call as
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    elements the elements of protocol are
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    message encoding message formatting and
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    encapsulation message timing message
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    size and message delivery options we
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    shall see each of this element in a
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    detailed manner message encoding means
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    the source that is the source computer
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    generates a message
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    it gives that message to the encoder in
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    order to generate signals once the data
  • 00:07:10
    is converted into signals now it is
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    given to the transmitter for
  • 00:07:14
    transmission you may be getting confused
  • 00:07:16
    why we need encoder here because we have
  • 00:07:20
    two kinds of transmission medium one is
  • 00:07:22
    a wired medium another one is a wireless
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    medium the source have to understand to
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    which medium it is connected to if it is
  • 00:07:29
    a wired medium the data have to be
  • 00:07:31
    converted into signals in order to
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    facilitate the data transmission on a
  • 00:07:35
    wired medium if it is a wireless medium
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    the sender have to encode the data in
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    the form of waves because this is a
  • 00:07:42
    wireless medium we can't send signals we
  • 00:07:45
    have to send waves and once the data is
  • 00:07:48
    sent through the transmission medium the
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    receiver receives the data and D course
  • 00:07:52
    it decoding means understanding it after
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    understanding it properly
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    it means the message has reached the
  • 00:07:59
    destination this is what message
  • 00:08:01
    encoding is all about the sender sends
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    the data the sender creates the data and
  • 00:08:06
    encodes the data and finally the
  • 00:08:09
    transmitter sends the data through the
  • 00:08:10
    transmission medium this transmission
  • 00:08:13
    medium takes the data to the receiver
  • 00:08:14
    the receiver after receiving the data it
  • 00:08:17
    decodes the data and after proper
  • 00:08:20
    decoding it means the message has
  • 00:08:22
    reached the destination this is what
  • 00:08:24
    message encoding is all about we shall
  • 00:08:26
    see the second element of the protocol
  • 00:08:28
    that is the message formatting and
  • 00:08:30
    encapsulation both sender and receiver
  • 00:08:33
    must mutually agree upon certain formats
  • 00:08:36
    which we call as formatted at the same
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    time when the receiver receives some
  • 00:08:40
    data it should identify who has sent
  • 00:08:43
    this data
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    we are going to add some information
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    with the data in order to identify the
  • 00:08:48
    sender and the receiver so we are not
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    going to just send data assets we are
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    going to encapsulate certain things like
  • 00:08:55
    the source information and the
  • 00:08:56
    destination information with the data so
  • 00:08:59
    that the right sender and the receivers
  • 00:09:01
    are identified and the third element in
  • 00:09:04
    the protocol part is message sizing if
  • 00:09:06
    there is a very big message to be
  • 00:09:09
    communicated to the destination human
  • 00:09:11
    breaks the message into smaller parts or
  • 00:09:14
    sentences say if this guy has a very big
  • 00:09:16
    content to be sent so what he does he
  • 00:09:19
    breaks the message into smaller parts or
  • 00:09:21
    sentences likewise our computer should
  • 00:09:25
    also do that if the capacity of the link
  • 00:09:27
    is very small but the data to be
  • 00:09:29
    transmitted is very big
  • 00:09:31
    this computer should break this big
  • 00:09:33
    message into smaller units which this
  • 00:09:36
    transmission medium can handle this is
  • 00:09:38
    what message sizing and this is one of
  • 00:09:41
    the thing a protocol should do and
  • 00:09:43
    message timing is the fourth element of
  • 00:09:45
    protocols and message timing deals with
  • 00:09:48
    flow control and response time mode
  • 00:09:49
    let's first talk about flow control
  • 00:09:52
    let's assume this guy is very fast the
  • 00:09:55
    sender is very fast and the receiver is
  • 00:09:57
    slow since the sender is very fast it
  • 00:10:01
    can send data at high speed what about
  • 00:10:03
    the receiver he can't handle that speed
  • 00:10:06
    if there is no flow control mechanism he
  • 00:10:09
    can keep so on sending data but he
  • 00:10:11
    cannot receive that data so the entire
  • 00:10:13
    communication will become useless it is
  • 00:10:15
    the responsibility of the protocol to
  • 00:10:17
    provide flow control mechanism at the
  • 00:10:20
    same time the sender is sending some
  • 00:10:22
    data and the receiver has to acknowledge
  • 00:10:24
    the data when the acknowledgement is
  • 00:10:27
    sent back to the sender the sender can
  • 00:10:29
    understand that the data is received by
  • 00:10:31
    the destination if the acknowledgement
  • 00:10:33
    is not received the sender have to wait
  • 00:10:35
    for a certain period of time after the
  • 00:10:37
    expiry of the time the sender will
  • 00:10:39
    retransmit the same so that we can
  • 00:10:41
    ensure guaranteed delivery and it is the
  • 00:10:44
    responsibility of the protocol to tell
  • 00:10:46
    how much time this computer should wait
  • 00:10:49
    for an acknowledgment and we have the
  • 00:10:51
    last element of the protocol and may say
  • 00:10:54
    delivery options there are three
  • 00:10:56
    delivery options one unique
  • 00:10:58
    - multicast 3 broadcast unicasting means
  • 00:11:02
    one sender and one receiver
  • 00:11:05
    it means this sender is going to send
  • 00:11:07
    data to exactly one receiver in the
  • 00:11:10
    network if the sender is sending the
  • 00:11:12
    data to exactly one destination it is
  • 00:11:15
    called as unicasting if the sender sends
  • 00:11:17
    the data to set of receivers but not to
  • 00:11:20
    all then this is multicast in
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    broadcasting means the sender sends the
  • 00:11:26
    data to all the participants in the
  • 00:11:28
    network then we call us broadcasting
  • 00:11:32
    and that's it guys now we shall just
  • 00:11:34
    recapture what we have seen today we
  • 00:11:36
    have seen what is data communication
  • 00:11:38
    that is the exchange of data between
  • 00:11:40
    nodes and we have also seen what is data
  • 00:11:43
    flow and we have seen the three data
  • 00:11:45
    flows simplex half-duplex and
  • 00:11:47
    full-duplex we have also seen the role
  • 00:11:50
    of protocols in computer networks not
  • 00:11:52
    only in computer networks even in real
  • 00:11:54
    time protocols has a very important role
  • 00:11:56
    to play with and we have also seen what
  • 00:11:59
    are the elements of protocols there are
  • 00:12:01
    five elements of protocols message
  • 00:12:03
    encoding message formatting and
  • 00:12:05
    encapsulation message size message
  • 00:12:08
    timing and finally the delivery options
  • 00:12:11
    I hope the session is informative thank
  • 00:12:13
    you all
  • 00:12:14
    [Applause]
  • 00:12:17
    [Music]
  • 00:12:23
    you
  • 00:12:25
    [Music]
Tags
  • protocoles réseaux
  • communication de données
  • flux de données
  • simplex
  • half-duplex
  • full-duplex
  • encodage
  • formatage
  • options de livraison
  • réseaux informatiques