Question

will rate

2) Recall that in TCP’s AIMD congestion control scheme, when segment loss is detected a TCP connection reduces the value of the threshold parameter to be one-half of the current congestion window. What if we tried a different adaptation such as reducing the value of the threshold by a constant amount instead (i.e., we no longer did a multiplicative decrease)?

a) In terms of fair sharing of link bandwidth, would this new TCP guarantee that TCP connections transmitting over a common link would achieve fair sharing? Explain.

b) Assuming one TCP connection was aware of how another TCP connection sharing a common link was adapting to loss, in terms of fair sharing of link bandwidth, what would be the effect of the first TCP connection reducing the value of its threshold by two times as much as the second connection reduced its threshold value?

Answer 1

a.) In terms of fair sharing of link bandwidth , the new TCP will be not be able to guarantee that the TCP connections transmitting over the link would be able to achieve fair sharing because each TCP connection will be having different requirement and the TCP congestion window will be able to to allow only upto a certain level to which the reduction can take place and sometime if the connection is taking more than enough to complete the transfer than the other connection have to suffer.

b.)As one of the TCP connection knows about the fair sharing of link bandwidth , so it will try to devour others to increase its bandwidth by showing fake segment loss to the network and as the result the other connection are reducing their values which causes other network to suffer from bandwidth reduction and make the user and other functionality suffer due to greed of one for the bandwidth.