Question

Four bits are used for packed sequences numbering is a sliding window protocol used in a computer network. What is the maximum window size?

1. 4
2. 8
3. 15
4. 16

Answer 1

Correct Answer - Option 3 : 15

Concept:

A sliding window protocol is a feature of packet-based data transmission protocols.

Sliding window protocols are used where reliable in-order delivery of packets is required.

Go-Back-N is the sliding window protocol. In this maximum window size is possible

Data

In GBN,

Number of bits = n = 4

Formula:

window size of sender + window size of receiver = Total size

∴ Ws +Wr   =  2ⁿ 

Calculation

W_r = 1

W_s= 2ⁿ – 1

∴ W_s= 2⁴ – 1 = 15

Maximum window size possible is 15