July, 2012
A9-R4: DATA COMMUNICATION AND NETWORKS TECHNOLOGIES
PART ONE
(Answer all the questions)
1. Each question below gives a multiple choice of answers. Choose the most appropriate one and enter in the “tear-off” answer sheet attached to the question paper, following instructions therein. (1x10)
1.1 In TCP/IP, Packets may arrive out of sequence (they may have been routed differently, or
one may have been dropped), so the ________ in each packets allow TCP to reassemble
the packets in the correct order and to request retransmission of any missing packets
A) Sequence numbers
B) Port numbers
C) Source_id number
D) Reassembling of the packets in the correct order is not permitted
1.2 UDP is a fast, unreliable protocol and unreliable means there is
A) No sequencing
B) No guaranteed delivery
C) No automatic retransmission of lost packets
D) All of the above