# Computer Networking : A Top-down Approach

 Authors: James F. Kurose, Keith W. Ross ISBN: 9780132856201 Edition: 6
 Chapter: Computer Networks And The Internet Exercise: Problems Question: 2

### Question by Anonymous on 29 Sep, 2016 at 12:31 PM

Equation 1.1 gives a formula for the end-to-end delay of sending one packet

of length L over N links of transmission rate R. Generalize this formula for sending P such packets back-to-back over the N links.

### Answer by Geroge on 11 Nov, 2018 at 12:52 PM

Consider the given data

N = Total number of links

R = Transmission rate

L = Packet length

P = packets that tramnsmit over the N link

The following is the formula of back-to-back delay of sending P packets, each of length L over N links of transmisson rate$R=d_{back-to-back}=PN\left ( \frac{L}{R} \right )$

### Cml Cgdm on 11 Nov, 2018 at 12:59 PM

first packet's delay $N\frac{L}{R}$  but, consecutive packet's delay would be $\frac{L}{R}$ , because they are not at the beginnig. They are at the router just before the final host. When a packet comes to final destination, at the same time next packet come to the router previous packet left. Then formula would be $N\frac{L}{R}+(P-1)\frac{L}{R}$  . First term for the first packet and second term is for remaining packets.

### Trueman on 09 Feb, 2019 at 05:05 AM

Yes this is the correct formula,  $N\frac{L}{R}+(P-1)\frac{L}{R}$

Post the discussion improve the above solution.