Data Communications

Data Communications

• Delivery
• Accuracy
• Timeliness
• Jitter

Components of Data Communications

• Message
• Sender
• Receiver
• Transmission Medium
• Protocol

Data Representation

• Text
• Numbers
• Image
• Audio
• Video

Data Flow

• Simplex 
• Half-Duplex
• Full-Duplex

Network Models

OSI Models

• OSI Model  में 7 Layer होते है, जो निम्नलिखित है

1. Application Layer
2. Presentation Layer
3. Session Layer
4. Transport Layer
5. Network Layer
6. Data-Link Layer
7. Physical Layer

Physical Layer

the physical layer is responsible for movements of individual bits from one note to next node.

• Representation Of Bits
• Data Rate
• Physical Topology
• Transmission Mode
• Synchronization of bits

Data-Link Layer

the data-Link layer is responsible for moving forms from one note to next node

• Framing
• Physical Addressing
• Flow Control
• Error Control
• Access Control

IP Address

IP v4 ⇒ 32 bit

Total number of IP address per Network = 2²⁴

Total number of possible Address = 2³²

1 Octet =8 bit

(1111111)₂=127

Total number of Network bit =2⁷= 128 ⇒ 128-2(MSB, LSB) =126

Sub netting

• There are 5 class

1. Class A
2. Class B
3. Class C
4. Class D
5. Class E

Class A

• Total Number of Possible  =2³¹

Class A Range = 1 ⇒ 126

Class B

• Total Number of Possible =

• 8 bit	8 bit	8 bit	8 bit
  Net ID	Net ID	Host Id	Host id

Class C

• Total Number of Possible =

Class D

• Total Number of Possible =

Class E

• Total Number of Possible =