Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Policies promoting wireless broadband in the United States wikipedia , lookup
Zero-configuration networking wikipedia , lookup
Computer network wikipedia , lookup
Airborne Networking wikipedia , lookup
Wireless security wikipedia , lookup
Network tap wikipedia , lookup
Wake-on-LAN wikipedia , lookup
Distributed firewall wikipedia , lookup
ILS 501 Unit 10 LAN Dr. Yan Quan Liu ILS SCSU What is LAN (local area network)? A group of computers dispersed over a local area and connected by a communications link that enables any device to interact with any other on the network. 5/25/2017 ILS 501 / Dr. Liu, SCSU 2 Types: Client-server LAN Peer-to-peer LAN 5/25/2017 ILS 501 / Dr. Liu, SCSU 3 Types of LANs Client/server LAN Clients microcomputers that request data 5/25/2017 Server - a powerful microcomputer that supplies data and manages shared devices ILS 501 / Dr. Liu, SCSU 4 Types of LANs Peer-to-peer LAN - all microcomputers on the network communicate directly with one another without relying on a server 5/25/2017 ILS 501 / Dr. Liu, SCSU 5 Components of LANs Connection or cabling system Microcomputers with network interface cards Network OS Other shared devices Routers, bridges, and gateways Hub 5/25/2017 ILS 501 / Dr. Liu, SCSU 6 Wireless local area networks (WLANs) A wireless LAN (or WLAN, for wireless local area network, sometimes referred to as LAWN, for local area wireless network) is one in which a mobile user can connect to a local area network (LAN) through a wireless (radio) connection 5/25/2017 ILS 501 / Dr. Liu, SCSU 7 802.11 tech for WLANs 802.11 is an evolving family of specifications for wireless local area networks (WLANs) developed by a working group of the Institute of Electrical and Electronics Engineers (IEEE). There are several specifications in the family and new ones are occasionally added. 5/25/2017 ILS 501 / Dr. Liu, SCSU 8 802.11 tech for WLANs 802.11g 30 MB/s 802.11n 300 MB/s 802 Standard comprises a family of networking standards that cover the physical layer specifications of technologies from Ethernet to wireless 5/25/2017 ILS 501 / Dr. Liu, SCSU 9 Access Point "In a wireless local area network ( WLAN ), an access point is a station that transmits and receives data (sometimes referred to as a transceiver). An access point connects users to other users within the network and ..." 5/25/2017 ILS 501 / Dr. Liu, SCSU 10 What are common network interface devices? 5/25/2017 ILS 501 / Dr. Liu, SCSU 11 Local area network technology- Network interface devices Common interface drivers/receivers connecting networks are: 5/25/2017 Bridge Router Gateway Firewall ILS 501 / Dr. Liu, SCSU 12 Network interface devices— Bridge A bridge is a product that connects a local area network to another local area network that uses the same protocol (for example, Ethernet) 5/25/2017 ILS 501 / Dr. Liu, SCSU 13 Network interface devices— Router A router is a device or software in a computer, that determines the next network point to which a packet should be forwarded toward its destination. The router is connected to networks with different operating systems. 5/25/2017 ILS 501 / Dr. Liu, SCSU 14 Network interface devices— Gateway A gateway is a network point that acts as an entrance to another network. It performs all functions of bridges and routers but slower in terms of speed than those two. 5/25/2017 ILS 501 / Dr. Liu, SCSU 15 Network interface devices— Firewall A firewall is a set of related programs, located at a network gateway server, that protects the resources of a private network from all unauthorized users from other networks. 5/25/2017 ILS 501 / Dr. Liu, SCSU 16 Ending notes: Essential Questions What does telecommunication mean? How is connection made to a network? What are the types and components of communication channels? What does the future hold in relation to telecommunications? 5/25/2017 ILS 501 / Dr. Liu, SCSU 17 Quick Note on Network Setups Simple Network Dialup 56k Modem plugged into phone line (1 computer) Phone Outlet Dialup Modem Computer Note: Uses regular phone cable 5/25/2017 ILS 501 / Dr. Liu, SCSU 25 Quick Note on Network Setups Simple Cable/Satellite Modem Cable/DSL/Satellite Modem plugged into cable/DSL/satellite outlet (1 computer) Charter and SBC/Yahoo are broadband Internet services Cable/ Satellite Outlet Cable/DSL/ Satellite Modem Note: Uses special Category 5 (Cat 5 RJ45) Cable called patchcords 5/25/2017 Computer *Most network equipment has a speed of 100Mbit/s ILS 501 / Dr. Liu, SCSU 26 Quick Note on Network Setups Cable/DSL/Satellite with Hub Cable/DSL/Satellite Modem plugged into cable/DSL/satellite outlet Requires 2 or more Internet Protocol (IP) connections (like 2 separate phone numbers) Cable/DSL Satellite Outlet Cable/DSL Satellite Modem Hub Computer Computer 5/25/2017 ILS 501 / Dr. Liu, SCSU 27 Quick Note on Network Setups Cable/DSL/Satellite with Router/Switch Cable/DSL/Satellite Modem and Router/ Switch* plugged into cable/satellite outlet Requires only 1 Internet Protocol (IP) connection (shares a phone number-saves $$) Cable/DSL Satellite Outlet Cable/DSL Satellite Modem Router/ Switch *Switches are smarter and faster than hubs 5/25/2017 ILS 501 / Dr. Liu, SCSU Computer Computer 28 Quick Note on Network Setups Cable/Satellite with Wireless Router/Switch Cable/Satellite Modem and wireless Router/Switch plugged into cable/satellite outlet Requires wireless network cards. Wireless is more convenient but less secure than Cables Cable/ Satellite Outlet Cable/ Satellite Modem Wireless Router/ Switch Computer Computer 5/25/2017 ILS 501 / Dr. Liu, SCSU 29 Quick Note on Network Setups Firewalls Firewalls are like the firewall in your car, which keep the heat and noise of the engine outside the passenger compartment Computer Firewalls are used to keep unwanted Internet users from accessing your network Once online, you are vulnerable w/o a firewall BlackIce is an example of firewall software Firewall Cable/ Satellite Outlet 5/25/2017 Cable/ Satellite Modem Router/ Switch & Firewall ILS 501 / Dr. Liu, SCSU Computer 30 Quick Note on Networks Firewalls Computer Firewalls work like Caller ID You set up the rules of who can “call” you Unrecognized callers are either denied, or asked for a password NOTE: Some software, like PCAnywhere and SQL Server require the firewall to specially configured 5/25/2017 ILS 501 / Dr. Liu, SCSU 31 Questions? 5/25/2017 ILS 501 / Dr. Liu, SCSU 32