CS 356 - Google Docs Part 3 PDF

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Description

- 404: Not Found - 505: HTTP Version Not Supported Cache: - Cache acts as both a server and client and is typically installed by the ISP

TCP - Go-Back N allows the sender to send multiple packets without waiting for ACKs. -

Flow control will always makes sure send window = ssthresh + In CA the congestion window (cwnd) = cwnd+1 + Once you clear SSthresh you start Congestion Avoidance

+ Used to have a slow start back into potentially crashing back down to one by overloading the receive window at a TO (timeout)

Missing packet 2 so cumulative acks just for 1, skips rest of packets, the three additional ACK 1’s are called triple duplicate ACK + Fast Retransmit if detects a triple duplicate ACK, will trigger the sender to retransmit missed packet (packet 2 in this case) + On the final ACK, the receiver sends an ACK of 5 to let the sender know that every packet up to 5 has come up until that point - Fast Recovery + Entered on a Triple Duplicate ACK (TDA) + On entry to this state, SSThresh is set to congestion window/2 (cwnd/2) + On exit of fast recovery, congestion window is halved and now equals SSthresh + In FR, executes Fast Retransmit and waits for ACK + Keeps cwnd/2 packets, which halves the retransmit rate Overview:

Flow Control - receiver controls sender to manage congestion Recitation TCP

a) b) c) d) e)

1-6,23-26 6-16,17-22 TDA (cwnd is halved) Timeout (goes down to 1) 17...