Question

Consider the two hosts A and B are connected through a direct link. The bandwidth of the link is 105 bits/sec, propagation speed is 2x108m/sec, the distance between A and B is 5000 km. What are the propagation and transmission delays if the file size is 20,000 bytes. a) 1600 msec and 2.5 msec b) 1200 msec and 25 msec c) 1200 msec and 2.5 msec d) 1600 msec and 25 msec ​

Answer 1

The Bandwidth (B) of the link is 10 bits/sec.

The propagation speed (v)= 2×10 m/sec.

The distance (d)= 5000 km =5×10^{6}106 m.

The file size (L)= 20,000 bytes=20,000*8=160,000=20,000∗8=160,000 bits.

Now applying the formula of propagation delay as follows-

\begin{gathered}t_{p}=\frac{d}{v}\\\end{gathered}tp=vd

where d= distance and v=propagation speed

\begin{gathered}=\frac{5*10^{6} }{20}\\ =250*10^{3}sec.\end{gathered}=205∗106=250∗103sec.

Now applying the formula of transmission delay -

\begin{gathered}t_{d}=\frac{L}{B}\\\end{gathered}td=BL

where L= number of bits and B= bandwidth

\begin{gathered}=\frac{160,000 }{10}\\ =16,000 sec\\.\end{gathered}=10160,000=16,000sec.