3.4-1 Principles of Reliable Data Transfer (Part 1)

Video presentation: "Transport layer: Principles of Reliable Data Transfer (Part 1)." Protocol mechanisms for reliable data transfer (rdt). Building an rdt protocol.
Computer networks class.
Jim Kurose
Textbook reading: Section 3.1, Computer Networking: a Top-Down Approach (8th edition), J.F. Kurose, K.W. Ross, Pearson, 2020.
See gaia.cs.umass.edu/kurose_ross for more open student resources.

Пікірлер: 53

  • @fsnaps
    @fsnapsАй бұрын

    Jim always smiling, makes the lessons so much more interesting

  • @abcde9421
    @abcde94212 жыл бұрын

    17:21 Worth listening to for a 100 times.

  • @jaronajohnson4412

    @jaronajohnson4412

    Жыл бұрын

    always makes me laugh :D

  • @eDog377

    @eDog377

    4 ай бұрын

    worth the wait

  • @VikasSharma05

    @VikasSharma05

    3 ай бұрын

    Really worth the wait. Don't know why, jar jar binks just flashed in my mind.

  • @sheesshoaib3816

    @sheesshoaib3816

    2 ай бұрын

    Its like chandler bing's blah balh blahh

  • @ahmedalhallag3338
    @ahmedalhallag33382 жыл бұрын

    I can't believe that the father of all computer networks papers and courses has only 1.1k subscribers :(

  • @vishweshgk6752

    @vishweshgk6752

    Жыл бұрын

    Ong 😩

  • @daroboro5137

    @daroboro5137

    8 ай бұрын

    10k after 1 year, so it's not so bad

  • @alkskillz7335

    @alkskillz7335

    2 ай бұрын

    Your generation were just lacking. Dw GenZs here to fix yall 😂

  • @asjadsalahuddin5918
    @asjadsalahuddin59183 жыл бұрын

    Made it so easy to understand , great work.

  • @Felipe-53
    @Felipe-5311 ай бұрын

    Thank you for blessing us with such well crafted lessons!

  • @MayCodeGuide
    @MayCodeGuide10 ай бұрын

    if anyone like me looking for a summery: The video discusses the challenges of reliable communication over an unreliable channel, exploring simple and increasingly realistic channel models. It goes on to explain the development of a reliable data transfer protocol, including the use of checksums and sequence numbers, and differentiates between unidirectional and bidirectional communication. The protocol's finite state machines and operations are also illustrated.

  • @hitarthmukundraykanakia3137
    @hitarthmukundraykanakia31373 жыл бұрын

    This is pure gold!! Thank you so much Professor Ross :)

  • @advaitamallik7703

    @advaitamallik7703

    Жыл бұрын

    *Kurose. Ross is a different dude.

  • @suyashmisra7406

    @suyashmisra7406

    8 ай бұрын

    He's a little confused but he's got the spirit

  • @t.sathwik5708
    @t.sathwik5708 Жыл бұрын

    explained the concepts of the text book in a fun and easy manner

  • @ricp
    @ricp Жыл бұрын

    Excellent lesson, thanks a lot, Professor!

  • @PenguinMaths
    @PenguinMaths3 жыл бұрын

    Great series!

  • @starless9
    @starless911 ай бұрын

    21:48 when receiver is in "wait for 1 from below" state and receives a packet from sender with sequence 0 it means... that the sender was looking for the ACK sequence 0 packet from receiver but it was corrupted in transmission. So the sender resends the sequence 0 packet and on receiving it uncorrupted receiver will resend the ACK sequence 0 packet so sender can move on to "wait for 0 from below"

  • @erayatsz3801

    @erayatsz3801

    6 ай бұрын

    Thanks bro that was very helpful

  • @LK-xq2jy

    @LK-xq2jy

    2 ай бұрын

    you are smart

  • @jianminglin4155

    @jianminglin4155

    2 ай бұрын

    Thanks for the explaining. Not sure if I got it right, but I think your last sentence should be "So the sender resends the sequence 0 packet and on receiving it uncorrupted, the receiver will resend the ACK sequence 0 packet so the sender can move on to "wait for 1 from above"". (The event notcorrupt(rcvpkt) && isACK(rcvpkt) occurs, so the sender moves on from the "wait for ACK or NAK 0" state to the "wait for call 1 from above" state.)

  • @SahilKumar-tj5lk
    @SahilKumar-tj5lk Жыл бұрын

    awesome !! Thanks a lot Professor

  • @SantoshKumar-lz2ti
    @SantoshKumar-lz2ti Жыл бұрын

    Question: at 13:40, for the sender fsm when the sender goes from 'wait for nak or ack' to 'wait for call from above' there is a event rat_rcv(rcvpkt),, does this mean the receiver sends a ACK/NAk messgae in the form of pkt ??

  • @christio02

    @christio02

    Жыл бұрын

    Yes, from the state "sender is waiting for ACK/NAK" from receiver, it only goes to "wait for call from above" when it receives an ACK from the receiver. If it receives a NAK, it will send a packet to the receiver and still be in in the "waiting for ACK/NAK" until it gets an ACK

  • @compscienthusiast
    @compscienthusiast Жыл бұрын

    I really appreciate breaking this down into FSMs and getting a better understanding of this process. However, I'm wondering how the receiver would know that the checksum is valid, and what would determine a non-corrupt checksum. I've used a checksum comparison in python before in the past but that relied on the sender receiving a packet back and then comparing that the sent and received packets have the same checksum. Using that logic, I'm wondering how we can determine that a packet is valid with a checksum if we don't know what to compare the checksum against. What would I be missing?

  • @starless9

    @starless9

    11 ай бұрын

    Granted I'm new to this topic but I'd think the checksum would be generated independently on the receiver side to compare against the checksum in the packet from sender. This could be done using a hash function similar to what is used with hash tables, applied on the data in the entire packet. With large enough prime numbers used in the hash function so the probability that an uncorrupted packet and corrupted packet will generate the same hash value/checksum will be very low. There is the possibility that the checksum in the packet from sender will be corrupted but that just causes a retransmit...

  • @janetan9620
    @janetan96202 жыл бұрын

    3.4-2: kzread.info/dash/bejne/qKybqpirXayvYrQ.html

  • @SantoshKumar-lz2ti
    @SantoshKumar-lz2ti Жыл бұрын

    ar 22:03 if it sends ACK , then the receiver will be like, now i should send next pkt so 1 is lost....is the sequnece 01010101?

  • @zakariaabdi1818
    @zakariaabdi18182 жыл бұрын

    How can bits be flipped ; Error with the hardware link layer(fibre optic for example)?

  • @abcde9421

    @abcde9421

    2 жыл бұрын

    During link transmission , and during storage in router memory

  • @mario999kart
    @mario999kart2 жыл бұрын

    In refer to important digital reliable data transfer, like digital money, value and important information (documents, ownership rights) exchange in the same setting, doesn't blockchain and PoW fit in here perfectly?

  • @hayotkamchiev
    @hayotkamchiev6 ай бұрын

    He has great taste in movies :)

  • @nitheshravikumar9462
    @nitheshravikumar94628 ай бұрын

    why do we send the packet through the unreliable channel ?

  • @bryan0x05

    @bryan0x05

    6 ай бұрын

    We can't just hope the channel is reliable every time, we need to be prepared to deal with an unreliable channel. This is how you compensate for that.

  • @LeeLee-vk2dz
    @LeeLee-vk2dz Жыл бұрын

    Save my life

  • @vishweshgk6752
    @vishweshgk6752 Жыл бұрын

    Sir I am big fan 🥰

  • @sandeepnbhandarkar4164

    @sandeepnbhandarkar4164

    Жыл бұрын

    Bigger fan sir

  • @nadiahalmutairy5350
    @nadiahalmutairy53502 жыл бұрын

    UDP is reliable protocol or not?

  • @DigaDupSuck

    @DigaDupSuck

    2 жыл бұрын

    unreliable

  • @thinkos6730

    @thinkos6730

    2 жыл бұрын

    The Protocol itself is unreliable. But you can make adjustments just as in the video on the application Layer Level to implement a reliable Service

  • @dev_jun
    @dev_jun Жыл бұрын

    🥰

  • @cby1189
    @cby1189 Жыл бұрын

    goat

  • @ashishroy4326
    @ashishroy43264 ай бұрын

    Hi GIT students, one night before exam

  • @delee8450
    @delee84502 ай бұрын

    i hope i find it earlier

  • @devmahad
    @devmahad7 ай бұрын

    rdt 1 - 2

  • @coolalgorithms
    @coolalgorithms3 ай бұрын

    NAK or NACK? I thought it was NACK

  • @youtuberemo9241
    @youtuberemo9241 Жыл бұрын

    :)

  • @user-wg4ms3xk3p
    @user-wg4ms3xk3p4 ай бұрын

    kzread.info/dash/bejne/oK2Jqretndu9l5M.html

  • @karanpreetsingh5966
    @karanpreetsingh59662 жыл бұрын

    Chemistry is you touching my arm and setting fire to my mind.

  • @SantoshKumar-lz2ti
    @SantoshKumar-lz2ti Жыл бұрын

    ar 22:03 if it sends ACK , then the receiver will be like, now i should send next pkt so 1 is lost....is the sequnece 01010101?

  • @SantoshKumar-lz2ti
    @SantoshKumar-lz2ti Жыл бұрын

    ar 22:03 if it sends ACK , then the receiver will be like, now i should send next pkt so 1 is lost....is the sequnece 01010101?