^{6}bits to a destination computer (D) over a network of two routers (R

_{1}and R

_{2}) and three links (L

_{1}, L

_{2}, and L

_{3}). L

_{1}connects S to R

_{1}; L

_{2}connects R

_{1}to R

_{2}; and L

_{3}connects R

_{2}to D. Let each link be of length 100 km. Assume signals travel over each line at a speed of 10

^{8}meters per second. Assume that the link bandwidth on each link is 1 Mbps. Let the file be broken down into 1000 packets each of size 1000 bits. Find the total sum of transmission and propagation delays in transmitting the file from S to D?

The network uses a Distance Vector Routing protocol. Once the routes have stabilized, the distance vectors at different nodes are as following

N1 : ( 0, 1, 7, 8, 4 )

N2 : ( 1, 0, 6, 7, 3 )

N3 : ( 7, 6, 0, 2, 6 )

N4 : ( 8, 7, 2, 0, 4 )

N5 : ( 4, 3, 6, 4, 0 )

After the update in the previous question, the link N1-N2 goes down. N2 will reflect this change immediately in its distance vector as cost, $$\infty $$. After the **NEXT ROUND** of update, what will be the cost to N1 in the distance vector of N3?

The network uses a Distance Vector Routing protocol. Once the routes have stabilized, the distance vectors at different nodes are as following

N1 : ( 0, 1, 7, 8, 4 )

N2 : ( 1, 0, 6, 7, 3 )

N3 : ( 7, 6, 0, 2, 6 )

N4 : ( 8, 7, 2, 0, 4 )

N5 : ( 4, 3, 6, 4, 0 )

The cost of link N2 - N3 reduces to 2 in (both directions). After the next round of updates, what will be the new distance vector at node, N3?

Consider a network with 6 routers R1 to R6 connected with links having weights as shown in the following diagram

All the routers use the distance vector based routing algorithm to update their routing tables. Each router starts with its routing table initialized to contain an entry for each neighbour with the weight of the respective connecting link. After all the routing tables stabilize, how many links in the network will never be used for carrying any data?