CSC $430$ Data Communications

Exercise $3\mathrm{.}1$

Computing an Internet checksum

Consider the two $16-$bit words $($shown in binary$)$ below. Recall that to compute the Internet checksum of a

set of $16-$bit words, we compute the one's complement sum of the two words. That is$,$ we add the two

numbers together, making sure that any carry into the $17$th bit of this initial sum is added back into the $1\text{'}$s

place of the resulting sum$)$; we then take the one's complement of the result. Compute the Internet

checksum value for these two $16-$bit words:

$1001101001010000$ this binary number is $39504$ decimal $($base$10)$

$1000101001100110$ this binary number is $35430$ decimal $($base $10)$

Solution: