Assume that there are 5 hops between two devices, A and B. The processing delay
ID: 3787548 • Letter: A
Question
Assume that there are 5 hops between two devices, A and B. The processing delay of interconnecting devices is 5sec. All links have a speed of 1Mbits/second. The speed of light in the link is 3x108 m/sec, and the length of each link is 1 km. With packet switched networking, the packet size is 1050Bytes, which includes 50 Bytes header. There are 10 packets that need to be transmitted from A to B. The queuing delay at each interconnecting devices is 5 msec question is below this c. Assume same amount of data needs to be transmitted over a circuit switching network. Let the total time needed for both setting up and terminating the connection be 70sec. What is the total delay in this case?
Explanation / Answer
Number of hops M=5,
Number of packets N=10,
Per-hop processing delay P=5*10^-6 secs,
Link propagation delay L = distance/speed of light = 1000meters/ 3*10^8= 3*10^-6 secs
Packet size = 1000 bytes (1050-50) = 1000*8=8000 bits,
Packet transmission delay T = packet size/transmission speed = 8000/1*10^6 bits/sec =8*10^-3 secs
Queuing delay=5msecs
Delay =Processing Delay + Queuing Delay Transmission Delay
ML + NT + (M-1) T + (M-1)P +Q=15*10^-6 secs+80msecs+32msecs+20*10^-6 secs+5 msecs
=5.035 msecs+112 msecs = 117.035 msecs=
Total delay =0.117 secs
Throughput=Total number of bits transmitted/Total Delay = 10000bytes/0.137sec=72,992bytes/sec