PPT Slides by Dr. Craig Tyran & Kraig Pencil Computer Networking – Part 2 MIS 320 Kraig Pencil...

PPT Slides by Dr. Craig Tyran & Kraig Pencil

Computer Networking – Part 2

MIS 320

Kraig Pencil

Summer 2014


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


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


LANs and Wide Area Network at Metropolitan Life Insurance Co.

LANs

(Located at regional office)

WAN


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


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/


VPN at WWU


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)


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


WWW Popularized Internet Usage

WW

W developed

Inter

net dev

eloped

http://en.wikipedia.org/wiki/File:WIntHosts1981-2009.jpg


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?


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)


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


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


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


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


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


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


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

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