Getting Connected CECS 5030 with Cathie Norris, Jennifer Smolka & Gerald Knezek CECS 5030 with Cathie Norris, Jennifer Smolka & Gerald Knezek

The Internet Today  Worldwide network of networks  Government agencies, educational institutions, hospitals, and commercial organizations  Worldwide network of networks  Government agencies, educational institutions, hospitals, and commercial organizations

The Internet Today  Phenomenal growth - 1 million/month  End of 2001 – 500 million users  Largest connection of networks in the world  Phenomenal growth - 1 million/month  End of 2001 – 500 million users  Largest connection of networks in the world

How the Internet Works  Local connection via modem, leased-line, ISDN, etc.  Router at provider’s point-of-presence  Local connection via modem, leased-line, ISDN, etc.  Router at provider’s point-of-presence

How the Internet Works  Small providers buy from big providers  NorthwestNet  NorthwestNexus  Big providers interconnect with each other  MCI  Sprint  AT&T  Small providers buy from big providers  NorthwestNet  NorthwestNexus  Big providers interconnect with each other  MCI  Sprint  AT&T MCIAT&T NWNETNWNEXUS

The Internet uses TCP/IP  Share common protocol TCP/IP  Transmission Control Protocol/Internet Protocol  “/” means it operates at two levels  Share common protocol TCP/IP  Transmission Control Protocol/Internet Protocol  “/” means it operates at two levels TCPIP

The Internet uses TCP/IP  Created more than thirty years ago by the Department of Defense Advanced Research Projects Agency (DARPA)  TCP/IP is the still the basis for the Internet  Created more than thirty years ago by the Department of Defense Advanced Research Projects Agency (DARPA)  TCP/IP is the still the basis for the Internet

The Internet uses TCP/IP  IP Address – unique identifier  IP resides in the Network Layer  TCP resides in the Transport Layer  IP Address – unique identifier  IP resides in the Network Layer  TCP resides in the Transport Layer

TCP/IP  Network Protocols  Internet Protocol (IP) Every computer on the Internet has a unique number which is the destination point Where you are and how I get there  Transmission Control Protocol (TCP) How is my data getting between you and me  Network Protocols  Internet Protocol (IP) Every computer on the Internet has a unique number which is the destination point Where you are and how I get there  Transmission Control Protocol (TCP) How is my data getting between you and me

TCP/IP  Application Protocols  Terminal Emulation (Telnet)  HyperText Transfer Protocol (HTTP)  File Transfer Protocol (FTP)  Simple Mail Transfer Protocol (SMTP)  Simple Network Management Protocol (SNMP)  Domain Name Service (DNS)  Application Protocols  Terminal Emulation (Telnet)  HyperText Transfer Protocol (HTTP)  File Transfer Protocol (FTP)  Simple Mail Transfer Protocol (SMTP)  Simple Network Management Protocol (SNMP)  Domain Name Service (DNS)

TCP/IP in the OSI Model Application Presentation Session Transport Network Logical Link Physical Application Presentation Session Transport Network Logical Link Physical FTP, Telnet TCPUDP IP ARP LLC Ethernet, WAN, Token Ring, FDDI SNMPTFTP NFS Seven Layer Open System Interconnect Model

TCP/IP in the OSI Model Application Presentation Session Transport Network Logical Link Physical Application Presentation Session Transport Network Logical Link Physical FTP, Telnet TCPUDP IP ARP LLC Ethernet, WAN, Token Ring, FDDI SNMPTFTP NFS

Internet Protocol (IP)  IP is a connectionless service that provides basic datagram delivery services.  IP takes care of addressing, or making sure the routers know what to do with your data when it arrives.  IP is a connectionless service that provides basic datagram delivery services.  IP takes care of addressing, or making sure the routers know what to do with your data when it arrives.

Internet Protocol (IP)  Not everything is sent over the Internet is not sent as a BATCH – or complete file  Sent over as packet of smaller pieces  256 characters or 512 characters (maybe longer)  Not everything is sent over the Internet is not sent as a BATCH – or complete file  Sent over as packet of smaller pieces  256 characters or 512 characters (maybe longer)

Internet Protocol  Every computer on the Internet has a unique address.  Information sent across IP networks is broken up into bite-sized pieces, called packets.  The information within a packet is usually between 1 and about 1500 characters long.  Every computer on the Internet has a unique address.  Information sent across IP networks is broken up into bite-sized pieces, called packets.  The information within a packet is usually between 1 and about 1500 characters long.

IP Envelopes From: To: IP Packet DATA

Internet Protocol  Some addressing information goes at the beginning of your message; this information gives your network enough information to deliver the packet of data.  Internet addresses consist of four numbers each less than 256.    Some addressing information goes at the beginning of your message; this information gives your network enough information to deliver the packet of data.  Internet addresses consist of four numbers each less than 256.  

Internet Protocol  IP Addresses  Class A Networks: 128.x.x.x  Class B Networks: x.x  Class C Networks: x  IP addresses are running out - Extensions to the current IP address protocol will be required - IPng  IP Addresses  Class A Networks: 128.x.x.x  Class B Networks: x.x  Class C Networks: x  IP addresses are running out - Extensions to the current IP address protocol will be required - IPng

Transmission Control Protocol  Reliable  TCP takes the information you want to transmit and breaks it into pieces.  TCP numbers each piece so receipt can be verified and the data can be put back in the proper order.  Acknowledgments  Reliable  TCP takes the information you want to transmit and breaks it into pieces.  TCP numbers each piece so receipt can be verified and the data can be put back in the proper order.  Acknowledgments

TCP Packet Encapsulation DATA To: Bytes 1 to 500 TCP Packet From: To: IP Packet

SLIP and PPP  Extensions of IP over voice-grade modem lines:  Serial Internet Protocol (SLIP)  Point-to-Point Protocol (PPP)  Allow internet access from the PC in your home by dialing up over modems to an Internet host.  Extensions of IP over voice-grade modem lines:  Serial Internet Protocol (SLIP)  Point-to-Point Protocol (PPP)  Allow internet access from the PC in your home by dialing up over modems to an Internet host.

TCP/IP Applications/Services  Terminal Emulation (Telnet)  File Transfer Protocol (FTP)  HyperText Transfer Protocol (HTTP)  Simple Mail Transfer Protocol (SMTP)  Simple Network Management Protocol (SNMP)  Domain Name Service (DNS)  Terminal Emulation (Telnet)  File Transfer Protocol (FTP)  HyperText Transfer Protocol (HTTP)  Simple Mail Transfer Protocol (SMTP)  Simple Network Management Protocol (SNMP)  Domain Name Service (DNS)

Terminal Emulation (Telnet)  Telnet is the login and terminal emulation program for TCP/IP environments  Primary function is to allow users to log into remote host systems  Requires username and password  Telnet is the login and terminal emulation program for TCP/IP environments  Primary function is to allow users to log into remote host systems  Requires username and password

How to Telnet  Open your DOS prompt  Type telnet  Your telnet window opens...  Open your DOS prompt  Type telnet  Your telnet window opens...

Uses for Telnet Today  Use of Telnet has diminished in recent years  Still being used to:  Connect to routers  Remote management of servers  Access to home system while traveling  Use of Telnet has diminished in recent years  Still being used to:  Connect to routers  Remote management of servers  Access to home system while traveling

File Transfer Protocol (FTP)  Important for building web pages  Primary mode of moving complete file from one computer to another  FTP is a program for transferring files in TCP/IP environments (ASCII or Binary)  Important for building web pages  Primary mode of moving complete file from one computer to another  FTP is a program for transferring files in TCP/IP environments (ASCII or Binary)

File Transfer Protocol (FTP)  Client – when you want information  Server – when you have the information  Typically, a user at a client computer downloads files from a remote server  Client – when you want information  Server – when you have the information  Typically, a user at a client computer downloads files from a remote server

FTP Terms: DOS  GET (MGET): You are downloading a file (or files) from another computer to your desktop  PUT (MPUT): You are uploading a file (or files) from your desktop to another computer  GET (MGET): You are downloading a file (or files) from another computer to your desktop  PUT (MPUT): You are uploading a file (or files) from your desktop to another computer

File Transfer Protocol (FTP)  Must logon to server  Requires username and password to access normal file system  Anonymous FTP allows access to anyone to a special file system (e.g. ftp.microsoft.com)  Must logon to server  Requires username and password to access normal file system  Anonymous FTP allows access to anyone to a special file system (e.g. ftp.microsoft.com)

FTP Terms: DOS  CD: Change Directory  Move up or down the directory structure  MD: Make Directory  New storage space  CD: Change Directory  Move up or down the directory structure  MD: Make Directory  New storage space

FTP Transparent Often FTP commands are transparent through your browser or through a FTP program like WS FTP.

HyperText Transfer Protocol  Primary application protocol that underlies the world wide web  Provides user access to the files that make up the web  Anywhere – anyplace – anytime  Primary application protocol that underlies the world wide web  Provides user access to the files that make up the web  Anywhere – anyplace – anytime

HyperText Transfer Protocol  Defines HOW they get there, not what they look like  Files can be in many different formats (text, graphics, audio, video, etc.)  Hypertext markup language (HTML) is the standardized language for creating web pages  Defines HOW they get there, not what they look like  Files can be in many different formats (text, graphics, audio, video, etc.)  Hypertext markup language (HTML) is the standardized language for creating web pages

Simple Mail Transfer Protocol  SMTP is the electronic mail transfer protocol used in TCP/IP environments  Provides a store-and-forward mail capability between host computer mail systems on the network  MIME (Multimedia Internet Mail Exchange) has become the standard for document attachments  SMTP is the electronic mail transfer protocol used in TCP/IP environments  Provides a store-and-forward mail capability between host computer mail systems on the network  MIME (Multimedia Internet Mail Exchange) has become the standard for document attachments

Domain Name Service  DNS is a TCP/IP service that maps network address numbers, for example, , to an easy to remember name, such as:  Internet and TCP/IP applications such as telnet, FTP and SMTP access DNS to locate names you’ve specified and resolves them to a numeric address and inserts it into a message for transport.  DNS is a TCP/IP service that maps network address numbers, for example, , to an easy to remember name, such as:  Internet and TCP/IP applications such as telnet, FTP and SMTP access DNS to locate names you’ve specified and resolves them to a numeric address and inserts it into a message for transport.

Domain Name Service  The address information is stored at many locations in a hierarchical structure, not at one central depository  Each site has a domain server that maintains information about the local nodes  The address information is stored at many locations in a hierarchical structure, not at one central depository  Each site has a domain server that maintains information about the local nodes Central Hub Node

Client/Server Architectures  Two-tier  “Fat” Client: User Interface + Application  Database Server  Example: File servers, SQL Servers  Two-tier  “Fat” Client: User Interface + Application  Database Server  Example: File servers, SQL Servers

Client/Server Architectures  Three-tier  “Thin” Client: User Interface only  Application Server  Database Server  Examples: Mail servers, Business applications  Three-tier  “Thin” Client: User Interface only  Application Server  Database Server  Examples: Mail servers, Business applications

Client/Server Architectures  Application Programming Interfaces  SQL, ODBC  APPC  TP Monitors  RPC  Interface Definition Languages  DCE  CORBA  Microsoft OLE  Application Programming Interfaces  SQL, ODBC  APPC  TP Monitors  RPC  Interface Definition Languages  DCE  CORBA  Microsoft OLE

References From Networking 101 Jim Cabral, Puget Technology Group, Inc. & Tammy Ruth, Children’s Hospital and Medical Center