Cisco Certificates and CCNA Course and Exams. Elements of Communication: Source, Encoder, Transmitter, Transmission Medium and Destination. Benefits and downsides of segmentation and multiplexing. Computer network definition, end devices «hosts», intermediary «network » devices and Peripherals. General categories of network media, wired, wireless, fiber, coaxial, STP and UTP. Network Types according to size: LAN, MAN, and WAN. Network Interface Card (NIC) Protocol, Protocol Suites and Industry Standards. The benefits of using a layered model. Difference between Protocol (TCP/IP) and Reference Models (OSI). OSI Layers and Corresponding Functions. Difference between L2, L3, nad L4 addresses

1. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
Network Fundamentals
Abdelkhalik Elsaid Mosa
Last Update: 20/9/2010
abdu.elsaid@yahoo.com
http://abdelkhalik.staff.scuegypt.edu.eg/

2. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
General Certifications

3. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
General Certifications
Certification Path Entry Associate Professional Expert
Design CCENT CCNA & CCDA CCDP CCDE
Routing & Switching CCENT CCNA CCNP CCIE R&S
Security CCENT CCNA Security CCSP – CCNP Security CCIE Security
Storage Networking CCENT CCNA CCNP CCIE SAN
Service Provider CCENT CCNA CCIP CCIE SP
SP Operations CCENT CCNA SP Ops CCNA SP Ops CCIE SP Ops
Voice CCENT CCNA Voice CCVP - CCNP Voice CCIE Voice
Wireless CCENT CCNA Wireless CCNP Wireless CCIE Wireless
In addition to Specialist Certifications in: Advanced Routing and Switching , Collaborations,
Data Center , Security, Wireless LAN, Video, and Foundation for Channel Partners

4. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
CCNA Course and Exams
• The CCNA certification validates the ability to install, configure,
operate, and troubleshoot medium-size routed and switched
networks.
• Required Exam(s)
640-802 (CCNA).
640-822 (ICND1)+ 640-816 (ICND2).
• CCNA Academy
1.Network Fundamentals.
2.Routing Protocols and Concepts.
3.Switching and wireless LAN.
4.WAN.

5. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
Elements of Communication
1.Message source: is the sender.
2. Encoder: transforms data from one form to another.
3. Transmitter: transmits signals across the transmission medium.
4.Transmission Medium: is the communication channel.
5.Destination: is the receiver.

6. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
Communicating the Messages
• In theory, data could be sent as one massive continuous stream
of bits.
 Problems:
1. No other device on the same network can send while there is one
sending.
2. If a link failed, the complete message must be retransmitted.
• Actually, data is divided into
smaller pieces “Segmentation”
 Benefits of segmentation:
1. Multiplexing: Multiple digital data streams are combined into one
signal.
2. Reliability: only the missing parts need to be retransmitted.

7. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
Communicating the Messages
Downsides of Segmentation and Multiplexing:
1. Complexity.
2. Time-consumption.

8. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
Computer network
• Group of devices which are connected together to give the user a
certain service.
 These devices can be either End devices “Hosts", Intermediary “Network
devices”, or Peripherals.

9. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
End Devices «Hosts»
• are also called Hosts.
• can act as client or server or both.
• are either the source or destination of a message.
• must have logical address (Ex: IP address)
• Ex: computers, network printers, VOIP phones, mobile devices.

10. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
Intermediary «Network » Devices
• Connect computers and networks together.
• Manages data flow through the network.
• Classify and direct messages according to QoS priorities.
• Regenerate and retransmit data signals.
• Permit or deny the flow of data, based on security settings.
• Notify other devices of errors and communication failures
Network Access Devices
Internetworking Devices
Security Devices
Modems

11. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
Peripherals
• Don’t have logical address.
• Don’t communicate directly in the network.
• Rely on their connected host to perform all network operations.
• Ex: Attached webcam, local printer, scanner

12. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
Network Media
• Provides the channel for message transmission.
• Types of network media
Metallic wires “Copper”: data is
encoded into electrical impulses.
Fiber optics: data is encoded into
pulses of light.
Wireless: data is encoded into
electromagnetic waves.
• Criteria for choosing media
Distance, environment, bandwidth,
cost of medium and installation,
and cost of connectors and equipment

13. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
Importance of Networks
• Software and file sharing
• Hardware sharing
• Modern Technologies (IP Telephony, Video Conferencing)

14. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
Network Types
1. According to Size
• LAN “Local Area Network”
• MAN “Metropolitan Area Network”
• WAN “Wide Area Network”
2. According to Media
• Wired
• Wireless

15. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
LAN
• Usually spans a single geographical area.
• Provides services to people within a common organization.
• Characterized by high data speeds.
• Administered by a single organization
• May be a single local network or interconnected local networks.

16. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
WAN
• Groups of LANs interconnected within large area.
• TSP interconnects theses geographical spanned networks.
• Characterized by slow data speeds
Ismailia Cairo

17. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
The Internet
• Is a global mesh of interconnected networks
• The most well known publicly accessible internetwork.
• Is created by the interconnection of networks belonging to ISPs.

18. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
Intranet and Extranet
• Intranet
 Private connection of LANs and WANs that belongs to an
organization.
 Accessible only by organization’s members, or others with
authorization.
• Extranet
 Internal network in an organization that also connects to
agents outside of the organization (suppliers, and clients).
 Accessible to authorized outsiders.
 A way for business partners to share information.

19. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
Network Representations
• Common data network symbols.
Activity

20. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
NIC
• NIC “Network Interface Card”, LAN adapter
 is a printed circuit board that provides network
communication capabilities to and from a personal computer
or other host device.
 The media plugs directly
into the NIC.

21. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
Protocol, Protocol Suites and Industry Standards
• Protocol: set of rules that govern communication between
devices.
• Protocol Suite: a group of interrelated protocols that are
necessary to perform a communication function.
• A Standard: is a process that has been endorsed by the
networking industry and ratified by a standards organization,
such as IEEE, and IETF.
• Protocols describe only what
functions are required of a
particular communication
rule but not how they are to
be carried out

22. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
The benefits of using a layered model
1. Assist in protocol design.
2. Fosters competition.
3. Prevents technology changes in one layer from affecting other layers
above and below.
4. Provides a common language to describe networking functions and
capabilities.

23. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
Protocol and Reference Models
• Protocol Model: provides a model that closely matches the
structure of a particular protocol suite. Ex. TCP/IP model.
• Reference Model: a common reference for maintaining
consistency with all types of network protocols and services.
 Aid in clearer understanding of the functions involved.
 Used for network design, and troubleshooting.
 Ex. OSI model.
All People Seem To
Need Data Processing

24. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
OSI Layers and Corresponding Functions
S/W represents an interface to the network. Everything at this layer is
application-specific. Ex: E-mail(SMTP, POP), Web Browser(HTTP), FTP, Telnet
Application
Presents the data in the proper format . Encoding, decoding, compression,
decompression, encryption and decryption. Ex: ASCII, AVI, JPG
Presentation
Syntax
Establishes, manages and terminates sessions “connections” between
applications. Controls dialogs between computers.
Session
Provides reliable/ unreliable transfer of data between end users.
Segmentation, sequencing, flow control and error detection. Ex: TCP & UDP
Transport
End-to-end delivery, Logical addressing EX: IPNetwork
Hop-to hop data delivery, Hop-to-hop addressing, Hop-to-hop error
detection, and Hop-to-hop flow control. Ex: Ethernet, FR, DSL, ATM
Data Link
Signaling and Encoding, Physical properties of the network such as Cable
length, Cable type, Bit rate, H/W interface types.
Physical

25. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
Protocol Data Units and Encapsulation
• Encapsulation: is the process of adding information to the
application data at each layer.
• PDU: is the form that a piece of data takes at any layer
• A PDU has different names to reflect its new appearance.
Data: Application layer PDU.
Segment/ Datagram: Transport Layer PDU
Packet: Internet layer PDU.
Frame: Network Access layer PDU.
Bits: Data actually transmitted over the medium.

26. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
Encapsulation

27. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
The sending and receiving process

28. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
Addressing in the network
• L2 Address “MAC”: Communicate
between devices on a single network
• L3 Add. “IP” “Logical Address”:
move data from network to another.
• L4 Add. “Port No.:
Identify the applications or services
running on hosts.
• Ipconfig, Ipconfig /all

29. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy
Network Devices

30. Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy