Week 1

1
Week 1

• Course overview

2
Learning objectives

• Network basics
• A classification
• The component view
• The layer view
• Importance of networking in organizations and
  related jobs
• Network design process and challenges
• Application exercise

3
Networks

• Group of computers or other devices connected by
  some type of transmission media
• Can be small or large LAN, MAN, WAN, BBN.
• Internet, intranet and extranet
• Two possible views
• The component view
• The layer view

4
Components of Networks

• Hardware
• Computers
• Clients/servers peer-to-peer networks
  mainframe/terminals
• Different types of servers and different types of
  clients
• Connectivity devices
• For a LAN NIC, repeater, hub, switch
• To interconnect LANs Bridge, switch, router,
  gateway
• Transmission media (AKA circuits) guided versus
  wireless
• Other Printers, connectors, storage devices,
  print servers
• Software
• Application softwares
• Network Operating Systems
• Protocols (See next slide)
• Agreed upon rules for transmitting data between 2
  devices
• Some of these rules are handled by hardware
  (physical layer)

5
Multi-layer view of networks

• Models that reduce the complexity of data
  communication between computers
• Modular approach
• The process of transferring data is divided into
  layers
• Each layer handles specific sub-tasks with
  specific protocols
• Communication occurs
• Between different layers on the same system
• Between similar layers on different systems
• See slide 10

6
OSI and course overview
7
Application Layers

• Handle the users connection to the network
• Include
• 7. Application Allows 2 application programs on
  separate computers to work together (HTTP, SMTP,
  SNMP)
• 6. Presentation Formats data for presentation to
  user (translation between data formats,
  encryption, compression)
• 5. Session Initiates, maintains and terminates
  each session between sender and receiver
  (synchronizes transmission and restarts it in
  case of interruption)

8
Internetwork Layers

• Move messages from one network to another (no
  direct relationship between sender and receiver)
• Include
• 4. Transport Segments message if necessary and
  ensures that all segments have been received and
  in sequence
• 3. Network Makes routing decisions

9
Hardware Layers

• Move messages from one computer (or device) to
  another
• Include
• 2. Data Link Deals with message delineation,
  error control and network medium access control
• 1. Physical Defines how to represent individual
  bits and the connectors to be used.

10
Message transmission using layers
11
Why do organizations need networks?

12
Networking jobs and certifications

• Network Designer (or Architect)
• Responsibilties Architecture of networks to be
  built/upgraded/expanded
• Knowledge Networking basics, business needs and
  products available
• Certifications Cisco network designer stream
• Network (or System) Administrator
• Responsibilities Daily operations (managing
  equipment trouble shooting)
• Knowledge Networking basics, configuration of
  NOS equipment, trouble shooting
• Certifications Cisco network administration
  stream Network MCSECNE
• Other related jobs Database administrator, email
  administrator.

13
Network challenges

• Meeting users needs!
• Peformance
• Cost effectiveness
• Compatibility between equipment from different
  vendors (Role of standards!)
• Security and Maintenance

14
Network Design Process

• Need AnalysisSpecs of user requirements
• Capacity (response time)
• Applications supported
• Security
• Technology Design
• Clients and servers
• Circuits and devices
• Cost assessment
• How can this be done?

15
Reaching a final network design
16
Thank you