ITED 328 Lecture 4 12 Feb 2004 Loosely covering Chapter 5 Internet and LAN Technology

ITED 3282 Section 1 - Networks A quick over view of networking in general. A network is a combination of computer, cables, NICs, and software. Each connection is called a "Node".

ITED 3283 Reasons to use a network: Share files. Transfer files. Access information and files. Use of an application by multiple users. Share printers ( or other resources). Use electronic mail ( ).

ITED 3284 NETWORK DEVICES: Network file server ( or servers). Network host computers. Individual workstations. Hubs Routers Gateways Bridge Repeaters Transmission media.

ITED 3285 More on devices: Hub- device that connects computers together. Routers connect two broadcast networks (at layer 3 the Network layer). Gateways connect multiple computers so they can access the network it at the same time. Connects networks that use different protocols( at layer 7, the gateway layer). Bridges connect LANS at the data link layer. Transmission media: fiber optic, coaxial, twisted pair, also air.

ITED 3286 Network configurations (a.k.a. topology) STAR RING Bus Peer to Peer (how we are going to do our next lab !)

ITED 3287 Network Protocols A method of coordinating communications on a network. Different types Low Level PROTOCOLS - no guarantee data is received. Mid level PROTOCOLS – Limited control Higher level PROTOCOLS User has control.

ITED 3288 LOW LEVEL PROTOCOLS Token Ring is a Local Area Network (LAN) protocol. The Token Ring protocol was first developed by IBM. Token Ring is standardized in IEEE that was published in The protocol deals with the problem of collision, which is defined as a state were two stations transmit at the same time. In order to avoid the situation of collision there was a need to control the access to the network. This kind of control is possible by the use of a control (permission) called token. The token is passed from one station to another according to a set of rules.

ITED 3289 Token Ring continued………….. Only the station in possession of the token is allowed to transmit data. Each station repeats the data, checks for errors, and copies the data if appropriate. When the data is returned to the sending station, it removes it from the ring. The token Ring protocol supports priorities in transmission.

ITED Token Ring continued………….. 2 ways to implement: Star or Ring Source knring/toknring.htm#Topology

ITED Ethernet Ethernet is communication over a single cable shared by all devices on the network. Once a device attached to this cable, it had the ability to communicate with any other attached device. This allows the network to expand to accommodate new devices without requiring any modification to those devices already on the network. Source

ITED FDDI Fiber Distributed Data Interface Used to connect two or more LANs over long distances ( i.e. transcontential).

ITED MID LEVEL PROTOCOLS Initiate communications, send and receive data, can terminate communications. NetBIOS, TCP/IP

ITED High Level Protocols Client /Server Unix / Linux LANS TCP/IP telnet ftp rlogin, rcp,rsh, ping NFS - Network Files System

ITED Software used for networks Novell, Windows NT Advanced Server

ITED The Seven layers of the OSI 7Application 6Presentation 5Session 4Transport 3Network 2Data link layer (sub layers Logical Link and MAC) 1Physical (hardware layer)

ITED Misc Info How the data is sent: Frames and Packets!

ITED THE INTERNET IP address 32 bit host address of a computer on the network Class A - high bit 0, 7-bit network number, 24-bit host number. n1.a.a.a 0 <= n1 <= 127 Class B - high 2 bits 10, 14-bit network number, 16- bit host number. n1.n2.a.a 128 <= n1 <= 191 Class C - high 3 bits 110, 21-bit network number, 8- bit host number. n1.n2.n3.a 192 <= n1 <= 223

ITED IP Addresses Dynamic or static IP Address IP Address network host subnet

ITED More Misc Info …… Domain name or fully qualified domain name is a way for all the computer in the world to have a unique name on the internet. ( STARTED by DARPA) Different domains: *.com *.edu, *.gov, *.net, *.org, *.mil, *.info, *.biz, *.int

ITED How to be connected: DIAL UP via phone and modem DSL - Digital Subscriber Line DSS - Direct Satellite Service Wireless Broad band - covers frequencies from audio to video

ITED Standards to Know of: IEEE IEEE has many subsections: a is for radio-based LAN protocol which speaks OFDM at 5GHz, one of the two wi-fi protocols.LANprotocolOFDM wi-fi b is wireless local area networks (WLAN) standard protocol which speaks DSSS at 2.4GHz b is one of the two wi-fi protocols. It operates at 11 megabits per second (Mbps).wirelesslocal area networksstandardprotocolDSSSwi-fi

ITED Continued …… An IEEE wireless local area network (WLAN) standard protocol, expected to be approved in June g offers wireless transmission over relatively short distances at up to 54 megabits per second (Mbps).IEEEwirelesslocal area networkstandardprotocol