Lab2

Question 3A

Propagation Delay = Length/C

Length = 36000m       C = 299792458 m/s

D=360002997924580.00012s0.12ms

           

(M = Message Length) (R= Transmission Speed)

Transmission delay = M/R

Transmission delay=102208110984ms

Latency = Transmission delay + Propagation delay

Latency = 0.12+84=84.12ms

Final Answer= 84.12ms

  

Question 3B

Propagation Delay = Length/C          Length = 2m

C = 299792458 m/s

D=22997924586.6710-6ms

Transmission Delay = M/R

Transmission delay=102208108.4109ms

Latency = Transmission delay + Propagation delay

Latency = 6.6710-6+8.4109

=8.4109ms

4)         We use Pipes to connect the flow of data from one process to another. These functions are needed to be able to implement the IPC using pipes. Those needed for communication using shared memory are as follows:

popen() – This begins another to send/receive data

pclose() – This ends the file stream that was opened

shmget() –  This allows us to accesses memory that is shared

shmctl() – This alters characteristics and permissions of a shared memory

shmat() –  This connects memory portions

shmdt() – This breaks memory portions

5)         We use Fread() and Fwrite() for reading and writing in binary mode. The main function of Fread() is that it uses memory that is saved in that space to a single unit type of data in which you will be reading in that location. The function of Fwrite () is that it copies the number of units in the first parameter that locates all the memory. Examples of both are listed below.

fread function :

size_p fread(void *ptr, size_p size, size_p nmemb, FILE *stream);

fwrite function :

size_p fwrite(const void *ptr, size_p size, size_p nmemb, FILE *stream);