Chapter 3 Intro to Routing & Switching

 Upon completion of this chapter, you should be able to:  Explain why protocols are necessary in communication  Explain the role of standards organizations in establishing protocols  Explain how the TCP/IP model and the OSI model are used for standardization of communication  Explain how data encapsulation allows data to be transported  Explain how local hosts access local resources  Explain how local hosts access remote resources

3.1.1

 Must follow same rules to communicate  Name some ways of everyday communicating  What do you need to communicate?  Network communication is similar  Source/destination  Rules of how message is sent include:  Message encoding; Message formatting and encapsulation; Message size; Message timing; Message delivery options

 ENCODING  Converting info for travel on media  Ex: bits into electricity, light, radio waves  DECODING  Interpret info from media  Ex: electricity, light, radio waves into bits

FRAME

 What if books where one long sentence? Hard to understand.  When you speak, messages broken up in sentences  Easier to process in smaller parts  Size of frames small  Messages broken into small pieces  Each segmented message is encapsulated & sent  Frames de-encapsulated, put back together & read at destination

 How fast or slow to talk  Access method  Speak at same time= collision  Wait turn to speak  Flow control  Speak fast= confusion  Control flow of data  Response timeout  No response= repeat question  Rules for how long to wait for response & retransmit

 Data is packaged up. What is this process called?  Encapsulation  The message and addressing info is encapsulated into a ___________.  Frame  Converting bits for travel on an Ethernet cable is known as what? Also, what is it converted into?  Encoding; electricity

 What kind of message goes to everyone?  Broadcast  A room is filled with 25 computers. PC1 sends a message to PC4, 7, 10, 15, and 20. What kind of message has been sent?  Multicast  Too much data is being sent too quickly between two communicating devices. If you don’t want dropped packets, what timing method would control how much is being sent at a time?  Flow control

3.2.1

 Many protocols work together to send data

3.2.2

 Set of protocols that work together  Standards developed to allow interoperability  IEEE  Proprietary protocols  One vendor controls how it operates  AppleTalk & Novell are examples  We’ll look at TCP/IP, an open standard

3.2.3

 Open standards are good  ISOC- Internet Society  IEEE- electrical standards  Ethernet  Wireless  ISO- standards/ created OSI model  EIA/TIA- electrical & telecommunications  ICANN- IP addressing/domains  IANA- runs under ICANN

 Define a proprietary protocol.  Protocol that an organization controls  What is the IEEE standard for Ethernet?   What is the IEEE standard for wireless?   You are requesting a web page…  What protocol is used 1 st ? HTTP  What protocol ensures delivery of it? TCP  What protocol helps find the best path? IP  What protocol formats it for transmission? Ethernet

3.2.4

 What is layer 4 of the OSI model?  Transport  What is layer 3 of the OSI model?  Network  Which layer finds the best path?  Network  Which layer is responsible for delivery of the data?  Transport  A piece of data at a layer is known as what?  PDU

 What layer turns data into bits for transmission on a cable, for example?  Physical  Where are IP addresses?  Network  HTTP is at which layer?  Application  Where is data divided into segments?  Transport  What is the PDU at layer 2?  Frames

3.3.1

 Data divided into smaller segments  Many conversations can be sent Multiplexing  Only parts of missing message can be resent

 Complete the activity on

 In the TCP/IP model…  Data is sent from the Internet layer to the Network Access layer. False  Segments are sent from the Transport layer to the Internet layer. True  At which layer of the TCP/IP model would you find the logical address, or IP address?  Internet layer  Name the OSI model from 7 to 1

3.3.2

 To find the MAC address of a device within your network…  ARP request sent as a broadcast DOES NOT GO OUTSIDE A NETWORK  Includes the IP of the destination  Every NIC looks at it; only one with that IP will respond with its MAC address

3.3.3

 If destination IP is outside of network, it gets sent to the default gateway address  Router port to get out of the network PC AA-AA-AA-AA-AA- AA PC BB-BB-BB-BB-BB- BB FTP Server CC-CC-CC-CC-CC- CC R R Web Server AB-CD-EF

 You don’t know the destination MAC  ARP can’t be sent outside of the network  The DG’s MAC address is substituted

 Which process finds out the MAC address of a PC on the local network?  ARP  At the Internet & Network layer, which address is logical?  IP address  Which address is physical? What layer of the OSI?  MAC; Data Link  When sending data outside your network, which address is used for the destination MAC?  Default gateway MAC address

 Complete the study guide handout  Take the quiz on netacad.com  Jeopardy review

In this chapter, you learned:  Devices must comply with communication rules and protocols. TCP/IP is an example of a protocol suite.  Most protocols are created by a standards organization such as the IETF or IEEE.  The most widely-used networking models are the OSI and TCP/IP models.

 Data that passes down the stack of the OSI model is segmented into pieces and encapsulated with addresses and other labels.  The process is reversed as the pieces are de- encapsulated and passed up the protocol stack.  The OSI model describes the processes of encoding, formatting, segmenting, and encapsulating data for transmission over the network.  The TCP/IP protocol suite is an open standard protocol.

 The names of layers in the OSI & TCP/IP models.  Protocol Data Units (PDUs) are data, segment, packet, frame, and bits.  ARP & Proxy ARP are used in sending data.  Applying models allows individuals, companies, and trade associations to analyze current networks and plan the networks of the future.

Chapter 3 Intro to Routing & Switching