self_doubt

Question

can we say that:

TCP uses only selective/independent acknowledgment not cumulative as it uses selective reject protocol???

and go back N uses both independent and cumulative acknowledgment?

Comments

@bikram sir plesae verify the answer

Answer 1

Go back N uses only cumulative acknowledgment since inorder packets are accepts only .

Yes TCP uses selective / independent acknowledgment not cumulative as it uses selective repeate protocol . it can also use go back protocol but it waste lots of bandwidth in form of retransmission.

Comments

I was just clearing about protocols like TCP, SR and go back N along with the type of acknowledgment

TCP uses SR protocol for communication so it will use independent acknowledgment,

for each packet received, receiver sends an ack

and go back N allows cumulative e.g for two or more packets , receiver can send only one ack

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tcp uses cumulative acks. not selective or independant

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TCP uses selective acks https://en.wikipedia.org/wiki/Transmission_Control_Protocol#Selective_acknowledgments to be efficient

Answer 2

TCP ACKs are cumulative. That is, if the i^th byte is acknowledged, it means that all previous bytes have been received too.

Comments

@sh!va,

 For a packet containing the TCP segment, it is only one ack right?

Answer 3

TCP uses both Selective repeat(it used by TCP 70% of the time) and GBN(it used by TCP 30% of the time) . GBN uses Cumulative ACK, Selective repeat uses Independent ACK . GBN uses more Bandwidth w.r.t Selective repeat .

Answer 4

I think TCP cn use both selective and cumulative acknowledgement.

But goBackN uses only cumulative acknowledgement