Consider a switched network between two end systems. Assume that no acknowledgements are sent and that the processing/queuing delay at the nodes are negligible. Draw the delay diagrams (space/time model) and compute the total end-to-end delays using N = 3, L = 1500, R = 25600, P = 512, H = 64, S = 1.5, D = 0. 01 and T = 1 where 

N = number of links between end systems 

L = message length (i.e. , data only) [bits] 

R = data rate for each link [bps] 

P = fixed packet size (i.e., packet header + data) [bits] 

H = packet header [bits] S = call setup time [sec] 

D = propagation delay for each link [sec] 

T = call teardown time [sec] 

for the following networks. 

If there are multiple packets to be transmitted, clearly depict all packets in the delay diagram (s) . 

a)  Circuit switching 

b)  Packet switching 

c) Virtual-circuit switching