(Solved): Q3.4: Consider the network with 5 nodes shown below, with the given link costs. The distance vector ...
Q3.4: Consider the network with 5 nodes shown below, with the given link costs. The distance vector algorithm (based on Bellman-Ford equation) is used to find the least-cost paths. [10 marks]. a) At time 0 , all nodes have distance estimates to nearest neighbors and send their local distance vector to their neighbors. What is the initial distance vector for router '
w'? Write your answer as
D_(w)(u)=H_(w)(v)=,D_(w)(w)=,D_(w)(x)=,D_(y)(y)=. [2 marks] - b) At time 1, the node '
x' receives distance vectors from its neighbors and computes its new local distance vector. What is the computed local distance vector from router '
x' to all the routers? Write your answer as
D_(x)(u)=_(d)D_(x)(v)=,D_(x)(w)=,D_(x)(x)=,D_(x)(y)=. [7 marks]. c) When distance vector routing is used, if the local link cost between two nodes greatly increases, what problem may happen? [1 mark]. Q3.3: Consider the figure below in which a TCP sender sends an initial window of 3 segments. Suppose the initial value of the sender->receiver sequence number is 303 and each segment contains 40 bytes. The delay between the sender and receiver is 7 time units, and so the first segment arrives at the receiver at
t=8. As shown in the figure below, the first segment is lost during the transmission. [4 marks] a) What are the sequence numbers for each of the three segments sent by the sender? [2 marks]. b) Give the ACK numbers that the receiver sends to the sender at
t=9and
t=10. [2 marks]
