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Suppose that a message 1001 1100 1010 0011 is transmitted using Internet Checksum (4-bit word). What is the value of the checksum?
in Computer Networks by Veteran (57.2k points) | 2.3k views

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As we are asked for 4-bit checksum, so divide the data into 4 bit words and add all.

1001 + 1100 + 1010 + 0011 = 100010

We want 4-bit checksum, bring 10 down and so add

0010 + 10 = 0100

And checksum will be the complement of 0100 which is 1011 .
by Veteran (50.9k points)
edited by
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You added four 4-bit words, how it produced a 6-bit output?
0
1001 + 1100 + 1010 + 0011

In decimal we can write this as,  9 + 12 + 10 + 3 = 34

Converting 34 to binary we get 100010
0
why only two bits brought down?

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