Networking Notes 1 - Overview of protocol and OSI model

Networking Notes 1

Protocol

Protocol is a set of urle and formats that govern the communication between communicating peers.

We can treated as providing a service.

Key Elements of a Protocol

• Syntax
  • Data formats
  • Signal levels
• Semantics
  • Control information
  • Error handling
• Timing
  • Speed matching
  • Sequencing

Protocol Layering

Task of communication broken up into modules
Each module is performed at different level/layer

Protocol architecture

Also called the protocal stack.
A function could use multiple modules.

Network Architecture

A set of layers and protocols

OSI Seven-Layer Model

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

1-3 is Network support group
4 is Transport group
5-7 is User support group

common Protocol of each layer

Application Layer

• SMTP
• FTP
• TFTP
• DNS
  Transport Layer
• SCTP
• TCP
• UDP
  Network Layer
• ICMP
• IPv4
  Data Link & Physical
• Inderlying Lan or Wan technology