This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: CSCI 415 Data Communication Networks Test 1 Solution Saad Mneimneh Visiting Professor Hunter College of CUNY NAME:—————————— • This test is closed book, closed notes, open minds... • There are 4 Problems (but each problem has multiple parts). • Scratch pages are provided at the end. Scratch pages will not be graded. • Make sure your answer is clear. • Do not leave unanswered questions even if you think you do not have the complete answer. Partial credit might be given. • Read all questions first. This will help you identify which questions you can easily answer first. Problem 1: Pitfalls in bit stuffing (10 points) Problem 2: Parity check codes (10 points) Problem 3: Sliding window (10 points) Problem 4: TCP vs. DLC (10 points) Total: (40 points) Problem 1: Pitfalls in bit stuffing (10 points) (a) (3 points) Bit stuffing must avoid the appearance of 01 6 within the trans mitted frame, so we accept as given that an original string 01 6 will always be converted to 01 5 01, where the second 0 is the stuffed bit. Describe that protocol at the sender and receiver in your own words. (b) (4 points) Show that a 0 must always be stuffed after 01 5 in the string 01 5 ...  {z } k 1 for any k ≥ 1, in order to destuff correctly at the receiver. Hint : show that this is true for k = 1, then work by induction. The base case ( k = 1): If 0 is not stuffed after 01 5 in 01 5 01, then the receiver cannot distinguish between 01 5 1 with a stuffed 0, and 01 5 01 as original data....
View
Full
Document
This note was uploaded on 03/27/2010 for the course CSCI 415 taught by Professor Saadmneimneh during the Spring '08 term at CUNY Hunter.
 Spring '08
 SaadMneimneh
 Computer Networks

Click to edit the document details