1. NT1210 Introduction to Networking
Unit 3: Chapter 3, TCP/IP Networks 1

2. Class Agenda 03/29/16 Learning Objectives
Lesson Presentation and Discussions.
Class Quiz 1
Discussion on Lab Activities.
Discussion on Assignments.
Break Times. 10 Minutes break in every 1 Hour.
Note: Submit all Assignment and labs due today.

3. Objectives
Compare and contrast the OSI and TCP/IP models and their applications to actual networks.
Explain the functionality and use of typical network protocols. 3

4. TCP/IP Network: Product Standards and Rules
Transmission Control Protocol (TCP) / Internet Protocol (IP).
Requests for Comment (RFC): Documents created by network stakeholders to comment and improve ideas for standards.
Define how products work.
Used by network designers.
Open source. 4

5. Defining the Rules for a TCP/IP Network
Hardware and software work together to create usable network.
Protocols (network software): Hypertext Transfer Protocol (HTTP), Simple Mail Transfer Protocol (SMTP), Post Office Protocol (POP), etc.
Used on networked devices (hardware): Phones, game systems, televisions, tablets, computers, software, networking devices, cables, etc. 5

6. Defining the Rules for a TCP/IP Network
TCP/IP identifies both stuff and how it works together:
Defines protocols.
Defines concepts of Local Area Networks (LANs) and Wide Area Networks (WANs).
Defines concept of links and nodes the functions of each.
Definition of TCP/IP network: Network built using TCP/IP standards and rules. 6

7. TCP/IP Network: TCP/IP Model
Commonly-used version of TCP/IP model has five layers.
TCP/IP Model 7
Figure 3-3

8. TCP/IP Network: Organizations Useful to TCP/IP
Sources of Standards in the TCP/IP Model 8
Figure 3-4

9. TCP/IP Network: LAN/WAN Standards
TCP/IP Using Other Standards for LAN and WAN 9
Figure 3-7

10. Comparing TCP/IP to Other Networking Models: OSI Model
Open Systems Interconnection (OSI) model.
ISO began work on OSI model following timeline that was close to TCP/IP’s:
Started in 1970s.
Progressed on individual standards in 1980s.
Allowed standards-based vendor products to start appearing by early 1990s.
The OSI Model 10
Figure 3-11

11. Comparing TCP/IP to Other Networking Models: OSI Model
The biggest differences between the TCP/IP and OSI models exist at the top.
The TCP/IP model defines many functions as part of the application layer, while the OSI model split those functions into multiple layers.
Mapping the Layers of the TCP/IP and OSI Models 11
Figure 3-12

12. Comparing TCP/IP to Other Networking Models: OSI Model
Three Example Standards, and the Phrases to Use 12
Figure 3-13

13. Understanding How a TCP/IP Network Works: LAN Physical Links
Both the sender and receiver must agree on the rules of how to use the electrical circuit. The sending NIC sends the bits over the loop to create the electrical signal. Signal varies over time to encode different bits. The receiving NIC must know what rules the sender uses so it can interpret the circuit changes into the correct 0s and 1s (bits).
NICs on Both Ends of a Cable Creating a Loop 13
Figure 3-15

14. Understanding How a TCP/IP Network Works: LAN Switches
Every Ethernet LAN device connects to the LAN using a cable. The cable installers run a cable from each device to a central place on that floor, usually to a switch that sits in a locked room called a wiring room. By connecting all the cables to the switch, all are connect to the LAN—and each other.
Using a LAN Switch to Physically Connect Devices to a LAN 14
Figure 3-16

15. Break Take 15 15

16. TCP/IP Network: Data Link Layer
Many protocols use headers and/or trailers to store bytes of info that control data flow through network.
Data Link protocols typically add both header and trailer.
Data Link Header and Trailer, Like a Couple of Sticky Notes 16
Figure 3-18

17. TCP/IP Network: Leased Lines
Enterprises use Layer 3 devices called routers to connect to the WAN leased line at each site.
The Telco connects the ends of the leased line directly into the enterprise’s routers in their WAN interfaces (ports) on each end of the link.
Physical Cabling of a Leased Line, from Each Customer Site to Central Office (CO) 17
Figure 3-21

18. TCP/IP Network: Data Link Protocol Encapsulation
Routers strip off old Data Link headers no longer needed and replace them with new Data Link headers needed for next leg (hop) of the data’s journey to its destination.
Encapsulation and De-encapsulation 18
Figure 3-23

19. TCP/IP Network: IP Addressing
Identifies device in TCP/IP network.
Every device must have unique IP address.
IP address has 32 bits written in dotted decimal notation (DDN) of four sets of eight bits each with dot (period) between each number.
Networking devices see decimal numbers as binary.
Binary IP Address
Equivalent Decimal IP Address
Example IP Addresses, Binary and DDN Formats 19
Table 3-1

20. Defining the Rules for a TCP/IP Network: IP Addressing
Each PC with a connection into the TCP/IP network has a unique IP address.
IP Addresses in a Network Diagram 20
Figure 3-25

21. Defining the Rules for a TCP/IP Network: IP Addressing
Routers play a big role with the IP protocol in that they route (forward) data based on the destination IP address. To do that, a router must connect using multiple interfaces to multiple data links. Example: Each router has 2 interfaces: One for WAN link and one for LAN.
Routers: Multiple Interfaces, Multiple IP Addresses 21
Figure 3-26

22. TCP/IP Network: IP Addressing Grouping
To make IP routing work, addresses grouped using rules.
IP groups addresses in different ways: Classful networks and subnetting .
Rules give network engineers flexibility in how they assign addresses, but still allow IP routing to work efficiently.
Five Classful IP Networks 22
Figure 3-27

23. TCP/IP Network: IP Addressing Grouping
IP Classful Networks
Class
IP Range
Designed for A –
Large enterprises, government agencies, etc. B –
Medium-sized businesses, organizations, etc. C –
For small entities and home networks D –
Multicast E –
Experimental, research
Five Classful IP Networks 23

24. TCP/IP Network: IP Routing
IP routing defines exactly how routers forward data in network.
Each router connects to multiple physical links so has multiple physical interfaces (ports).
Router has rules that tell it how to make routing decisions.
IP routing relies on two ideas:
Sender addresses data.
Routers forward data based on destination IP address.
Routers keep routing information in their RAM in IP routing tables 24

25. TCP/IP Network: IP Routing
Moving data on network relies on routers to forward data to correct destination host.
Routers talk to each other (using protocols) to learn about IP addresses in network.
Routers keep routing information in their RAM in IP routing tables.
Routing Tables on R1 and R2, for Network 25
Figure 3-29

26. Defining the Rules for a TCP/IP Network: IP Routing
PC11 sends an IPv4 packet to PC21 by adding an IP header that includes its address and the destination’s IPv4 address to the data (payload).
Web Client Host PC11 Puts into the IP Header Destination IP Address Field 26
Figure 3-28

27. TCP/IP Network: Forwarding Packets
IP creates and adds IP header to payload.
Sending host adds IP header (Network Layer address) and Data Link layer header/trailer before sending data onto network.
IP header follows Data Link header in frame.
Encapsulation on the Sending Host: Frame and Packet 27
Figure 3-30

28. TCP/IP Network: Forwarding Packets
Frame: Encapsulated data that includes Data Link header and trailer—plus everything in between (including IP header).
Packet: What sits between Data Link header and trailer.
Router discards Data Link header and trailer when it receives frame, leaving IP packet.
Router then encapsulates packet into new Data Link header and trailer (with next hop Data Link address) when it forwards IP packet.
Encapsulation/de-encapsulation process continues until IP packet delivered to destination. 28

29. TCP/IP Network: Routing IP Packets
Routers: Remove Packet from Frame, Send Packet inside a New Frame 29
Figure 3-31

30. TCP/IP Network: Transport Protocols
Transport layer protocols provide the connection to network applications (apps) and Multiplexing.
Widening Scope of Higher TCP/IP Layers 30
Figure 3-32

31. TCP/IP Network: Transport Protocols TCP and UDP
Transport layer connects source and destination applications.
Port number: Used by transport protocol to identify each destination app.
Transmission Control Protocol (TCP) – Connection- oriented.
User Datagram Protocol (UDP) – Connectionless. 31

32. Defining the Rules for a TCP/IP Network: TCP/IP Roles Summary, Part 4
Layer Name
Key Functions
Host or Network
Device Focus
Physical
Physical parts that communicate, and energy over those parts (electricity, light, radio).
Network
Cables, radio
Data Link
Rules about when to use physical links; Addressing specific to the physical links.
LAN Switch
Internetwork (Network)
Logical addressing (addressing independent of the physical links); routing.
Router
Transport
Communications functions useful to apps, but likely useful to many apps.
Host
Any endpoint device
Application
Communication functions specific to a particular app.
TCP/IP Model Summary 32
Table 3-2

33. Mind Mapping
A diagram used to visually organize information.

34. Summary: This chapter…
Distinguished between the key terms related to networking standards, including standard, protocol, and model.
Listed the layers of the TCP/IP model and explained the purpose of the TCP/IP model.
Named standards organizations on which the TCP/IP model relies.
Briefly compared the history of the OSI and TCP/IP models and classified the layers of each in comparison to each other. 34

35. Summary: This chapter…
Summarized the key functions of Ethernet LANs.
Summarized the key functions of leased line WANs.
Explained how IP addressing and IP routing work together.
Defined how different headers help move data through a network.
Listed two Transport layer protocols: TCP and UDP. 35

36. Lab Activities
Complete all Lab Activities on Chapter 3 of the Lab Manual.
Unit 3 Lab 3.1: Network Reference Models
Unit 3 Lab 3.2: The OSI Reference Model
Unit 3 Lab 3.3: The TCP/IP Model
Unit 3 Lab 3.4: Data Link Connections
Lab will be completed in class.

37. Assignment Unit 3
Assignment Unit 3 Assignment 1: Networking Models Review
Assignment Requirements
Respond to the multiple-choice questions.
Complete the Define Key Terms table.
Print and submit in the next class.
Reading Assignment: Read Chapter 4 before coming to the next class

38. Unit 3 Research Project 1
Unit 3 Research Project 1: Chapter 4 Mind Maps