Problem

Using UDP$-$based Internet sockets, write a C program, myping.c$,$ which mimics the standard ping command as shown below:

$ $./$myping sys$22.$cs$.$abc.edu

from sys$22.$cs$.$abc.edu $(157\mathrm{.}252\mathrm{.}16\mathrm{.}50)$: time $=0\mathrm{.}620$ ms

from sys$22.$cs$.$abc.edu $(157\mathrm{.}252\mathrm{.}16\mathrm{.}50)$: time $=0\mathrm{.}445$ ms

from sys$22.$cs$.$abc.edu $(157\mathrm{.}252\mathrm{.}16\mathrm{.}50)$: time $=0\mathrm{.}500$ ms

from sys$22.$cs$.$abc.edu $(157\mathrm{.}252\mathrm{.}16\mathrm{.}50)$: time $=0\mathrm{.}615$ ms

from sys$22.$cs$.$abc.edu $(157\mathrm{.}252\mathrm{.}16\mathrm{.}50)$: time $=0\mathrm{.}495$ ms

where time is the Round Trip Time $($RTT$),$ the delay between the client sending the ping message and receiving the pong message. Note that standard ping programs use the Internet Control Message Protocol $($ICMP$)($to be discussed later$),$ not UDP.

Your client program should send five ping messages to the server at every second interval $($see the sleep function$).$ For each message, your client is to determine and print the RTT in milliseconds when the corresponding pong message is returned $($see the clock function$).$

Recall that UDP is an unreliable protocol; a packet sent by the client or server may be lost. The client may have to send more than five ping messages to receive five pong messages from the server.

To handle the client$$s ping request, write another C program, myping$\_$server.c$,$ which runs on the server. Your server program must be UDP$-$based and may use any ports between $9000$ and $9999.$ Run your server with:

$ $./$myping$\_$server