Computer Communication Networks
Mr. Kunjan D Shinde
Assistant ProfessorDepartment of Electronics and Communication Engineering
PESITM Shivamogga.
2Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Data Link ControlFraming
Fixed Size framingVariable size framing
Flow and Error Control
ProtocolsNoiseless Channel and Noisy Channel
Simplest stop and wait ARQStop and Wait Go back N ARQ (sliding window, )
Selective Repeat ARQ HDLC
Modes of operationHDLC frames
Computer Communication Networks
Contents Chapter 2
3Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
A frame in a character-oriented protocol
4Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Byte stuffing and unstuffing
6Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
A frame in a bit-oriented protocol
8Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Bit stuffing and unstuffing
9Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
The most important responsibilities of the data link layer are flow control and error control. Collectively, these functions are known as data link control.
Flow Control
Flow control refers to a set of procedures used to restrict the amount of data that the sender can send before waiting for acknowledgment.
10Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
12Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Simplest Protocol
13Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Sender site Algorithm for Simplest Protocol
14Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
receiver site Algorithm for Simplest Protocol
15Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Flow diagram for Simplest Protocol
16Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Stop-and-Wait Protocol
17Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Sender site Algorithm for Stop-and-Wait Protocol
18Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Receiver site Algorithm for Stop-and-Wait Protocol
19Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Flow diagram for Stop-and-Wait Protocol
20Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Although the Stop-and-Wait Protocol gives us an idea of how to add flow control, noiseless channels are nonexistent. We discuss three protocols in this section that use error control.
In a Data Link Layer, at any time if a error is detected , then that specific frame is retransmitted this process is call Automatic Repeat Request (ARQ)
The following are the protocols used in Noisy Channel
Stop-and-Wait Automatic Repeat RequestGo-Back-N Automatic Repeat RequestSelective Repeat Automatic Repeat Request
22Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Stop-and-Wait ARQ Protocol
23Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Sender-site algorithm for Stop-and-Wait ARQ
24Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Sender-site algorithm for Stop-and-Wait ARQ
25Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Receiver-site algorithm for Stop-and-Wait ARQ Protocol
26Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Flow diagram Stop-and-Wait ARQ Protocol
28Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Go back N ARQ Protocol
29Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Sender-site algorithm for Go back N ARQ
32Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Receiver-site algorithm for Go back N ARQ
34Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
36Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Sender-site algorithm for Go back N ARQ
37Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Sender-site algorithm for Go back N ARQ
38Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Receiver-site algorithm for Go back N ARQ
39Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Flow Diagram for Go back N Protocol
40Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
41Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Stop-and-Wait ARQ is a special case of Go-Back-N ARQ in which the size of the send
window is 1.
42Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Window format for Selective Repeat ARQ
43Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Window format for Selective Repeat ARQ
44Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Design for Selective Repeat ARQ
45Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
In Selective Repeat ARQ, the size of the sender and receiver windowmust be at most one-half of 2m.
Sender-site algorithm for Selective Repeat ARQ
46Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Sender-site algorithm for Selective Repeat ARQ
47Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Sender-site algorithm for Selective Repeat ARQ
48Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Receiver-site algorithm for Selective Repeat ARQ
49Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
50Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
51Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Design of piggybacking in Go-Back-N ARQ
52Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
High-level Data Link Control (HDLC) is a bit-oriented protocol for communication over point-to-point and multipoint links.
53Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
54Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
55Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
56Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
57Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Study point to point protocol
58Mr. Kunjan D. Shinde, Asst. Professor, Dept. of E&CE, PESITM Shivamogga.
Computer Communication Networks
Chapter 2: Data Link Control
Thank u
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