ppt slides by dr. craig tyran & kraig pencil computer networking – part 2 mis 320 kraig pencil...
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PPT Slides by Dr. Craig Tyran & Kraig Pencil
Computer Networking – Part 2
MIS 320
Kraig Pencil
Summer 2014
PPT Slides by Dr. Craig Tyran & Kraig Pencil
A. Game Plan
• Introduction (Part 1 notes)• Distributed processing (Part 1 notes)• Client/Server processing (Part 1 notes)• Local area networks (Part 1 notes)• Wide area networks• Wireless networks• Cloud Computing
PPT Slides by Dr. Craig Tyran & Kraig Pencil
H. Wide Area Networks
1. Wide area network (WAN)
– May span 100s 1000s of miles globe
– May connect LANs
– Organizations often lease communication lines (from AT&T, Verizon-MCI, Sprint, etc.) to establish a private network
– Common for international organizations
– If all of an organization is hooked up, call it an “Enterprise Network”
– Example: See figure next slide
PPT Slides by Dr. Craig Tyran & Kraig Pencil
LANs and Wide Area Network at Metropolitan Life Insurance Co.
LANs
(Located at regional office)
WAN
PPT Slides by Dr. Craig Tyran & Kraig Pencil
H. Wide Area Networks (cont.)2. The Internet: A type of WAN:
• A network of networks
• Evolution• When was it created?
• Why was it created?
• Who were the early users??
• “Top innovation” of past 25 years
• CNN (1/18/05)
• Governance• The Internet Society
Source: www.campusvillagetoledo.com/speed.htm
PPT Slides by Dr. Craig Tyran & Kraig Pencil
H. Wide Area Networks (cont.)3. Virtual private network (VPN)
• A “virtual” software extension of a private network.
• It has no hardware of its own. It transmits over a public network (usually the Internet).
• VPN software protects the security of the internal network by requiring authorization. It protects transmitted data through encryption.
• Example : sales people in the field can log into the internal network from anywhere over the Internet.
• Advantages
• Flexible: connect from anywhere
• More secure than basic Internet
• Less expensive than leased WAN
Image Source: www.alpha-apr.com/vpn/
PPT Slides by Dr. Craig Tyran & Kraig Pencil
H. Wide Area Networks (cont.)4. Does the Internet = World Wide Web (WWW)?
– Internet Describes the computer network infrastructure
– WWW An information sharing approach used by clients/servers on Internet
• Invented (1989-1991) by Tim Berners-Lee
• Composed of a “web” of documents with links to other documents
• Hosted by client-servers connected to the Internet
• Uses a “browser” application todisplay the document
Illustration: http://www.w3.org/2007/Talks/1211-whit-tbl/#(1)
PPT Slides by Dr. Craig Tyran & Kraig Pencil
H. Wide Area Networks (cont.)
4. Internet = WWW? (continued)
• WWW uses “HTTP”: Hyper Text Transport Protocol– Defines how messages are formatted and transmitted
• What happens when you submit a URL via web browser?– Determine protocol
– Find the server
– Request/display file
http://www.wwu.edu/mis321.htm
PPT Slides by Dr. Craig Tyran & Kraig Pencil
WWW Popularized Internet Usage
WW
W developed
Inter
net dev
eloped
http://en.wikipedia.org/wiki/File:WIntHosts1981-2009.jpg
PPT Slides by Dr. Craig Tyran & Kraig Pencil
Running out of Internet “bandwidth”?
• http://arstechnica.com/tech-policy/news/2010/10/now-thats-bandwidth-international-net-links-add-13tbps-in-2010.ars
• http://www.macworld.com/article/61123/2007/11/internetcapacity.html
• 2008 – often predicted we will run out of capacity (“bandwidth”) by 2011.
• Growth of International Internet Bandwidth• What do you think?
PPT Slides by Dr. Craig Tyran & Kraig Pencil
I. Wireless Networks1. A new frontier ??
2. Types of wireless networks• Wireless local area networks (WLANs)• Personal area networks (PANs)• Wireless metropolitan area networks (WMANs)
PPT Slides by Dr. Craig Tyran & Kraig Pencil
I. Wireless Networks (cont.)3a. Wireless local area networks (WLANs)
• Similar to a LAN, without the cables• A fast-growing network
technology for businesses (and individuals)• e.g., Laptop usage
• 2002: 20% of business laptops
• 2007 (est.): 99% of laptops
• e.g., Business networking• UPS, hospitals
PPT Slides by Dr. Craig Tyran & Kraig Pencil
I. Wireless Networks (cont.)3b. WLAN: What is Wi-Fi?
• Wi-Fi: “Wireless Fidelity”• Based on “IEEE 802.11” set
of protocol standards • Ethernet with CSMA/CD
• Short range transmitter-receiver (up to 300 ft) communicates with Wi-Fi NIC receiver
card/antenna 54 Mbps Sources: NetGear, Linksys
PPT Slides by Dr. Craig Tyran & Kraig Pencil
I. Wireless Networks (cont.)3c. WLAN: “Hot spots”
• Location that offers access to Wi-Fi network• e.g., WWU Red Square, Starbucks, airports, hotels
• Want to find a hot spot?• CNET Hotspot Zone
3d. WLAN: Concerns• Limited range
• Security• “War driving”
• Eavesdropping
• Wi-Fi typically needs to have security features enabled and configured(see http://www.cnn.com/SPECIALS/2004/wireless/flash.html )
Image sources: Starbuck, WWU, www.gugli.it
PPT Slides by Dr. Craig Tyran & Kraig Pencil
I. Wireless Networks (cont.)4. Personal area networks (PANs)
– Network for devices close to one’s person• e.g., phone, PDA, computer, wireless barcode scanner
– Bluetooth technology (IEEE 802.15)• Can link multiple devices within 30 feet• 1 Mbps + transmission rate
– Example applications• Earpiece for cell phone• Package scanning for UPS• Wireless mouse/keyboard
PPT Slides by Dr. Craig Tyran & Kraig Pencil
I. Wireless Networks (cont.)
5. Wireless metropolitan area networks (WMANs)– One approach: WiMax
• Based on “IEEE 802.16” set of protocol standards
– Advantages• Broad range (up to 31 miles)• High speed transmission
(75 Mbps)• Wireless
– Implications …• Will WiMax (or something
like it) replace Internet cable-modem and DSL service?
Historical progression:1G: analog cell phone2G: digital cell phone3G: digital cell phone + Internet4G: high speed 3G
PPT Slides by Dr. Craig Tyran & Kraig Pencil
Cloud ComputingNot cloud Your data and app is on your computer
Cloud Your data or app ison a server on the Internet
Also Cloud Your data or app can be on any of multiple servers on the Internet
PPT Slides by Dr. Craig Tyran & Kraig Pencil
Latest Hot Topic: Cloud Computing
“Cloud” = “Internet”• Instead of running an application on
your own computer, use a service from the web that does about the same thing.
• Example– Use Google Apps instead of
Microsoft Office applications.
• Hypervisor introduction from VMware
Some PR Videos for the Cloud• “SalesForce.com” offers CRM (customer
relationship management) services “in the cloud”.http://www.youtube.com/watch?
v=ae_DKNwK_ms
• The key idea in this video is that cloud computing gives you the flexibility to change quickly when necessary.http://www.youtube.com/watch?
v=C4O3ufQ23xg
• We talked about servers – now virtual servers!http://www.youtube.com/watch?
v=EvXn2QiL3gs