© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public ITE PC v4.0 Chapter 1 1 Network Services Networking for Home and Small Businesses – Chapter 6

ITE PC v4.0 Chapter 1 2 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Compare and Contrast Clients and Servers  Server – host running software application that provides information to other hosts on network – all servers use same types of protocols and standards – Example: Web Server  Client – name given to an application that a host uses – Example: Web browser host uses web client software to request a web page

ITE PC v4.0 Chapter 1 3 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Types of Servers  DNS (Domain Name Server/System) – translates the IP address of web site from its domain name  Telnet – allows remote login/access to a device  – like its name implies they supply access  DHCP-used to supply dynamic IP addresses, first used by network clients before other servers.  Web – uses HTTP protocol  FTP – used to download and/or upload files between clients and servers

ITE PC v4.0 Chapter 1 4 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Client-Server Protocols  Application Layer Protocols – determine the way in which a server and client interact – HTTP – way to convey information on the web – SMTP – used to transfer from server to server –FTP – used to transfer files

ITE PC v4.0 Chapter 1 5 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Activity #1  Open the Cisco curriculum on your computer and navigate to page and complete the server activity that asks you to match the server with the request from the computer. Drag the server to the requesting computer screen to see if you are correct.

ITE PC v4.0 Chapter 1 6 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Server Cost  Lets take a quick look at the cost of servers.  Using lets compare the prices and features of the following two servers. To complete your comparison you may design a venn diagram or T-Chart (either on paper or on the computer)  Insert a definition of what a server is then compare 2.  Servers to Compare 1) Lenovo ThinkServer TS140 Item # LQW model # 70A4001RUS and 2) Cybertron PC Magnum TSVMIB1281 Tower Server Item # C Model # TSVMIB1281and compare the two servers based on the following items.  1) Price 2)Total Memory Size 3)Processor Speed 4)Processor Type/Class 5)Power 6) Warranty

ITE PC v4.0 Chapter 1 7 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Graphic Design – 6 Server Layout  Using a piece of printer paper create a graphic design of the six main types of servers that are commonly found within the networking world today. Besides listing the names of the servers also include a description of each server and include the above info inside a picture of a server picture.

ITE PC v4.0 Chapter 1 8 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public TCP (Transmission Control Protocol)  Used by FTP and HTTP to allow transmissions to occur  Provides acknowledgment of delivery of the packet – similar to registered mail  How it works... – Message into segments – Segments are then numbered (1,2,3…..) –Keeps track of the number of segments – If sender does not receive the segments – The lost portion is retransmitted  Use of TCP will slow down delivery. Why??

ITE PC v4.0 Chapter 1 9 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public UDP Protocols  U = UNRELIABLE  “Best effort delivery”  No acknowledgment, no guarantee – similar to “snail mail”  No retransmission  Used by: – streaming audio – streaming video – VoIP

ITE PC v4.0 Chapter 1 10 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Activity  Go to Cisco Page and test your knowledge over TCP and UDP protocols.

ITE PC v4.0 Chapter 1 11 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Port Numbers in Client-Server Conversations  Used by both TCP and UDP  Keeps track of different conversations across the network  Every message includes a source and destination port  Destination port – sent by client in the segment to tell what service is requested Port 80 = HTTP Port 21 = FTP

ITE PC v4.0 Chapter 1 12 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public HTTP  Used to display web pages  HTML – helps display the contents of a web page  HTTP – unsecured protocol – Port 80  HTTPS – provides extra security/encryption – Port 443

ITE PC v4.0 Chapter 1 13 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Port Numbers Graphical Design  Open the port numbers graphical design sheet on Mr. Smith’s website and complete the graphical design of the key port numbers that are requested.

ITE PC v4.0 Chapter 1 14 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public DNS Server (Domain Name System)  Translates a domain name (URL) into an IP address  Some groups –.com –.edu  Port 53 = DNS – used if clients wants an IP address of a web site or host  To convert to one would use what type of application?

ITE PC v4.0 Chapter 1 15 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public In The Lab Activity  Select a person to work with. One person open the lab found on page , the other person will open up the CMD prompt and as a team complete the lab. Only one answer sheet is needed and this can be typed or hand written on a sheet of paper.  You have 10 minutes to complete

ITE PC v4.0 Chapter 1 16 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public FTP (File Transfer Protocol)  Host must run FTP client access to access the FTP server  Two ports used to communicate – FTP Request = Port 21 – To transfer files when open = Port 20

ITE PC v4.0 Chapter 1 17 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Protocols used by Severs  SMTP (Simple Mail Transfer Protocol) – used by client to send messages to local server – allows servers to communicate with each other – Port #25  POP3 (Post Office Protocol) – receives/stores messages for the users – when client connects to server messages are downloaded to the client; messages are removed from server – Port #110  IMAP (Internet Message Across Protocol) – receives/stores messages but keeps messages on the server unless deleted by user – Port #143

ITE PC v4.0 Chapter 1 18 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public VoIP (Voice Over IP)  IP packets carry digitized voice as data  How it works – Download client software from company service provider – Once software is installed, user selects a unique name – Calls made by selecting a username from list

ITE PC v4.0 Chapter 1 19 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public IM  What client software enables logged in users to communicate with other logged in users in real time? Instant Messaging  What common program is used for Instant messaging?

ITE PC v4.0 Chapter 1 20 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Port Numbers  ICANN (Internet Corp for Assigned Names and Numbers) – assigns port numbers  Messages received will have a destination port number which will help the computer use the correct application to open up data.

ITE PC v4.0 Chapter 1 21 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public  Copy the Port # list found on page it will look close to the chart shown on the next slide.

ITE PC v4.0 Chapter 1 22 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Port Numbers

ITE PC v4.0 Chapter 1 23 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Activity #2  Navigate to page and complete the Port Number activity. Look at the destination port number and select the appropriate protocol.

ITE PC v4.0 Chapter 1 24 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public The Protocol Stack What term is used to describe how TCP/IP protocols are layered and interact to format, address, and transmit information across a network? Protocol Stack  Upper Layers – message content  Lower Layers – help to move data

ITE PC v4.0 Chapter 1 25 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Encapsulation (sending data)  From top to bottom  Application data broken into segments – segments contain source and destination ports  TCP segments sends it down to Internet layer – source and destination IP added (packet)  Packet put into a frame – header and trailer added header = source and destination MAC trailer = error checking  Broken into bits – encoded onto the media (cabling)  What 3 things are found in the Ethernet Header and Trailer?

ITE PC v4.0 Chapter 1 26 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Question  A device receives an Ethernet frame and recognizes the MAC address as its own. What does the device do to the message to get to the encapsulated data?  Removes the Ethernet header and trailer  A client has decoded a frame and started the de- encapsulation process. In which order does the de- encapsulation process occur?  1) remove Ethernet header and trailer 2) remove IP header 3) remove TCP header 4) pass data to the application

ITE PC v4.0 Chapter 1 27 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public De-encapsulation (receiving data)  From bottom to top  Bits are decoded from the media  Frame removes header and trailer  Packet removes the IP address – source and destination IP  Segment is received and reassembled for the user – viewing a web page

ITE PC v4.0 Chapter 1 28 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Why Use a Layered Model? 1)Allows competition between vendors – can all work together  2)One layer does not affect other layers  3)Allows for a common language  TCP/IP Model and its layers are below…

ITE PC v4.0 Chapter 1 29 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public OSI MODEL  Developed in 1984  Reference model for how computers interact with each other  Organized into more specific groups than the TCP/IP Model

ITE PC v4.0 Chapter 1 30 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public OSI Layer Research Task  We are going to break into seven groups (Size will be 3-4 members)  Each group is to design a one-page sheet that illustrates the assigned OSI layer using printer paper.  At the top of the paper should be the name of the layer, somewhere else on the sheet should be a brief description about what occurs at the layer which should include any devices and/or protocols that are used. A picture should also be included to help someone remember the overall purpose of the layer (the group decides the picture but it must be relevant).  We will post the seven layers in the room when each group is finished.  Use the Internet or the Cisco curriculum (Chapter 6) to assist your group.

ITE PC v4.0 Chapter 1 31 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public OSI Model  Layer 1 is mainly concerned with cables, wires and electricity.  Layer 7 is concerned with applications and programs.  Easy Way to Remember The OSI Model  All People Seem To Need Data Processing

ITE PC v4.0 Chapter 1 32 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public IP Header  What is contained in the IP Header? source and destination IP addresses  Using google perform a search for IP Header which should show the various components that make up the header. Copy the image to your notes before you go on to the next step below.  Activity #3 – Go to page within the Cisco curriculum and drag the correct addresses, or port numbers into the Ethernet frame, remember the IP portion will be IP addresses, the TCP will be port numbers and the Ethernet portions will be MAC addresses.

ITE PC v4.0 Chapter 1 33 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Packet Tracer Activity  Open Packet tracer and then using File, Open select the lab called Cisco I over PDU information sent between client and servers. PDU stands for Protocol Data Unit.

ITE PC v4.0 Chapter 1 34 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Quiz  Take the Cisco chapter 6 quiz found on page to test your knowledge.

ITE PC v4.0 Chapter 1 35 © 2007 Cisco Systems, Inc. All rights reserved.Cisco Public