This is the first Lecture for the IT and fundamental for CCNA learners

1. CSC341 – NETWORK
MANAGEMENT
Jahan University
Computer Science Department
Lecturer: Islahuddin Jalal
Master in Cyber Security
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2. Topics to be discussed
 What is network? Types and levels of network
 Living in the OSI model world, h/w used in network
 Basic TCP/IP: fundamentals
 Basic TCP/IP:TCP and UDP communications
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3. Class Policy
 A student must reach the class-room in time. Late comers may join the class
but are not entitled to be marked present.
 Attendance shall be marked at the start of the class and students failing to
secure 75% attendance will not be allowed to sit in final exam.
 The assignment submission deadline must be observed. In case of late
submission, ten percent may be deducted from each day.
 Those who are absent on the announcement date of the assignment/test.
Must get the topic/chapter of test/assignment confirmed through their peers.
 Mobile phones must be switched-off in the class-rooms.
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4. Grading Evaluation for Network Management
Internal Evaluation
Midterm Exam 20%
Attendance 5%
Assignment/Presentations 5%
Quizzes/Tests 10%
Total Internal Evaluation 40%
Final-term Examination
Final-term Exam 60%
Total Marks 100%
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5. What is Network?
 A collection of computing devices that are connected in various ways in order
to communicate and share resources
Usually, the connections between computers in a network are made using
physical wires or cables
However, some connections are wireless, using radio waves or infrared signals
 The generic term node or host refers to any device on a network
 Data transfer rate The speed with which data is moved from one place on a
network to another
 Data transfer rate is a key issue in computer networks
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6. Types of Network
 There are three main types of Networks
 LAN A network that connects a relatively small number of
machines in a relatively close geographical area
 MAN The communication infrastructures that have been
developed in and around large cities
 WAN A network that connects two or more local-area
networks over a potentially large geographic distance
Often one particular node on a LAN is set up to serve as a
gateway to handle all communication going between that
LAN and other networks
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7. Types of Network
 HAN A network contained within a user's home that connects a
person's digital devices.
 VPN A network that is constructed by using public wires — usually
the Internet — to connect to a private network, such as a
company's internal network.
 SAN A high-speed network of storage devices that also connects
those storage devices with servers
Communication between networks is called internetworking
The Internet, as we know it today, is essentially the ultimate
wide-area network, spanning the entire globe
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8. Network Topologies
 Network Topology: Physical layout of a network is called network topology.
 There are different types of network topologies
 Star Topology
 Bus Topology
 Ring Topology
 Mesh Topology
 Hybrid topology
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9. Star Topology
 All the computers are connected through a central connection point (hub,
switch etc)
 A single break in the cable would only take down communication to one
computer
 As hub failure would take down the entire network
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10. Bus Topology
 All the computers are connected in straight line
 Terminators must be used at each end of a bus segment to prevent signals
from bouncing
 A single break in the cable would take down the entire network
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11. Ring Topology
 All the computers are connected in circular fashion
 Data is passed around the ring from computers to computer
 A break in the cable would take down the entire network
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12. Mesh Topology
 All the computers are connected to all other computers
 Typicallly used in a WAN environment
 Provides fault tolerance in the event of a connection failure
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13. Hybrid Topology
 Different types of topologies can be used together to form a hybrid topology.
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14. Questions Regarding Topologies
 Which kinds of network topologies connect all devices to a central device?
 What kind of network topology is this?
 What kind of network topologies is used in 802.11 wireless network?
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15. Basic Network
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Hub
Pamir Khkula
How would you say the
PC named Pamir
communicates with the
PC named Khkula?
“Hey Khkula, I love you”
or
“Hey 192.168.0.3, I love
you”
Which one is right?
Both are wrong But why?

16. Basic Networking
 Because Pamir is actually going to use Khkula’s MAC address
 But what would happen if pamir only knows her name and doesn’t know her IP
address and Mac Address?
 Pamir query
Khkula Response
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This Problem is solved by
ARP
Source Destination protocol Info
192.168.0.2 Broadcast ARP Who has 192.168.0.3? Tell 192.168.0.2
Source Destination protocol Info
192.168.0.3 192.168.0.2 ARP 192.168.0.3 is at 00:0b:db:99:d3:5e
192.168.0.3 192.168.0.2 NBNS Name query response NB 192.168.0.3

17. Questions
 What would happen if the network grows and grows and become a large
network?
 What would be the solution?
 What is the Process to split a larger network into a smaller Networks?
 Which devices are needed for network Segmentation?
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The Network speed become low
To split the network into a smaller Network
Network Segmentation
Routers, Switches and Bridges

18. Network Appliances
 Load balancer
 Proxy Server
 Content filter
 VPN Concentrator
 Cache Engine
 WAN Optimizer
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19. Load Balancer
 A load balancer is a device that acts as a reverse proxy and distributes
network or application traffic across a number of servers. Load balancers are
used to increase capacity (concurrent users) and reliability of applications.
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20. Proxy Server
 Functions as an intermediary b/w a web browser and the internet
 E.g. Tor (application)
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21. Content filter
 Can be S.W and H.W
 Prevent access to certain items harmful if opened or accessed
 The most common items to filter are executables, emails or websites.
 E.g Firewall
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22. VPN Concentrator
 Networking device like router
 Specifically designed for creating and managing VPN communication
infrastructures
 Provides secure creation of VPN connections and delivery of messages b/w
VPN nodes
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23. Cache Engine
 Also called cache server
 Save web pages or other internet content locally
 By placing previously requested information in temporary storage
 Speeds up access to data and reduces demand on an enterprise’s bandwidth.
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24. WAN Optimizer
 WAN Optimization = WAN acceleration
 It is a device used to maximize the efficiency of data flow across a WAN
 Increase the speed of access to critical applications and information
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25. Assignment (Network Devices)
 Define all Network devices along with their functions and advantages and
disadvantages using Internet, books, conference paper, journals etc.
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26. Internetworking Model
 OSI Reference Model (ISO)
 TCP/IP suite (DARPA)
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27. OSI Reference Model
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28. OSI Reference Model (late 1970)
 Why OSI model came into being?
 Before 1970s computers on the network communicate only with other computers of
the same manufacturer e.g IBM devices communicate only with IBM devices.
 To breakup this barrier, the ISO brought up OSI Model

29. What is OSI Reference Model?
 The OSI model is the primary architectural model for networks
 It describes how data and network information are communicated from an
application on computer, through the network media, to an application on
another computer.
 The OSI Reference model break up this approach into seven layers

30. Please Do Not Throw Sausage Pizza Away
 Physical Layer (1)
 Data Link Layer (2)
 Network Layer (3)
 Transport Layer (4)
 Session Layer (5)
 Presentation Layer (6)
 Application Layer (7)

31. Application Layer (7)
 Provide a user interface
 To allow access network resources
 Also responsible for identifying and establishing the availability of the
intended communication partner and determining whether sufficient
resources for the intended communication exist.
 Protocols are
 FTP, SMTP, HTTP etc

32. Presentation Layer (6)
 Presents data to the Application layer
 Responsible for
 data translation
 Data encryption and compression
 Protocols are
 ASCII, MPEG, JPEG etc

33. Session Layer (5)
 Responsible for setting up, managing and tearing down the sessions.
 It also provide dialogue control b/w devices or nodes
 It coordinates communication between systems, and serves to organize their
communication by offering three different modes such as
 Simplex
 Half duplex
 Full duplex
 Protocols are RPC, NFS (to allow transparent access to network resources) etc

34. Transport Layer (4)
 Segment and reassemble data into a data stream
 Establish a logical connection b/w sending host and receiving host
 Provides reliable or unreliable delivery
 Data integrity is ensured by maintaining flow control
 Performs error correction before retransmit
 Protocols are
 TCP
 UDP
 etc

35. Flow Control
 Data integrity is ensured
 Prevents a sending host from overflowing the buffer in the receiving host
 Properties of flow control
 The segments delivered are acknowledged back to the sender upon their reception
 Any segments not acknowledged are retransmitted
 Segments are sequenced back into their proper order upon arrival at their
destination
 A manageable data flow is maintained in order to avoid congestion, overloading
and data lost
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36. Connection-oriented communication
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37. Three-way Handshake
 The first “connection agreement” segment is a request for synchronization
 The next segments acknowledge the request and establish connection
parameters – the rules- b/w hosts. These segments request that the receiver’s
sequencing is synchronized here as well so that a bidirectional connection is
formed
 The final segment is also an acknowledgment. It notifies the destination host
that the connection agreement has been accepted and that the actual
connection has been established. Data transfer can now begin.
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38. Characteristics of connection oriented
communication
 A virtual circuit is set up
 It uses sequencing
 It uses acknowledgements
 It uses flow control
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39. TCP Flags (TCP control bits)
 SYN
 ACK
 PSH
 URG
 FIN
 RST
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40. Network Layer (3)
 Also called layer 3
 Provides logical addressing which routers use for path determination
 Track the location of the devices on the network, determine the best way to
move data
 Routers are specified at this layer
 Protocol is IP

41. Data Link Layer (2)
 Combine packets into bytes and bytes into frames
 Provides access to media using MAC address
 Performs error detection not correction
 Protocols are
 Ethernet (to share the same bandwidth among all hosts)
 Token Ring(circulating in the ring)
 etc

42. Sublayers of Data link layer
 MAC (Media Access Control):
 Defines how packets are placed on the media.
 Every one share the same bandwidth
 Error Notification is done here
 LLC (Logical Link Control)
 Identifying network layer protocols
 LLC header Inform the data link layer what to do with the frames when received.
 Also provide flow control and sequencing of control bits
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43. Physical Layer (1)
 Moves bits between devices
 Specifies voltage, wire speed
 Pin-out of cables

44. END
Thanks for
hearing…………………….