DLL framing
WAP in C/C++ to implement DLL framing method by bit stuffing.
THEORY & CONCEPT-:
• Each frame begins and ends with a special bit pattern called a flag byte [01111110].
• Whenever sender data link layer encounters five consecutive ones in the data stream, it
automatically stuffs a 0 bit into the outgoing stream.
• When the receiver sees five consecutive incoming ones followed by a 0 bit, it automatically destuffs the 0 bit before sending the data to the network
layer.
PROGRAM in C/ C++-:
#include
#include
#include
void main()
{
char text[100],text1[100];
int k,n,count=0,i,j,p;
clrscr();
printf(“Enter text at sender end:”);
gets(text);
n=strlen(text);
for(k=0;k<=n;k++)
{
text1[k]=text[k];
}
for(i=0;i<n;i++)
{
if(text[i]==’1′)
count++;
if(text[i]==’0′)
count=0;
if(count==5)
{
p=1+1;
for(j=n+1;j>p;j++)
{text[j]=’0′;}
n++;
count=0;
}
}
printf(“Bit stuffed code is:”);
printf(“01111110”);
for(k=0;k<strlen(text);k++)
printf(“%c”,text[k]);
printf(“01111110”);
printf(“\n Text at reciever end:”);
for(k=0;k<=n-1;k++)
{
printf(“%c”,text1[k]);
}
getch();
}
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