1. 1.NET Web Forms Internet Introduction © 2002 by Jerry Post

2. 2 Internet Overview Individual Internet service provider (ISP) Phone company Network service provider (NSP) Backbone network Phone company Company Web site Dial-up: 33.3 - 56 Kbps ISDN: 128 Kbps DSL: 256 Kbps - 6 Mbps Cable: 1 to 10 Mbps Cable company T1: 1.544 Mbps T3: 44.736 Mbps OC3: 155.52 Mbps OC12: 622 Mbps

3. 3 Internet Connections  Electricity  Cable Company  Power Company (weak experiments)  Telephone Company  Light  Private (How do you get land access?)  Telephone Company  Direct connect lasers  Microwave  Satellite  Cell phones  Private  Limited distance  Limited bandwidth

4. 4 Connection Capacities

5. 5 Internet Connections  Long distances are best handled by fiber optics.  Wave division multiplexing (WDM) has increased bandwidth by 1000 times.  Over 90 percent of existing fiber is unused.  Last Mile Problems  Monopolies suck.  Telephone, DSL about 1 mbps down and 128 kbps up for $60/mo.  Cable, about 1.5 mbps down and 256 kbps up for $50/mo.  Wireless  Most pure Internet wireless companies died.  Cell phones, 3G possible up to 2 mbps, unknown cost  Wi-Fi/802.11b—one end must still be anchored to Internet (cost!)  Servers require a full-time connection (leased line)  Note that you pay two people: the carrier and the ISP  Frame Relay: 512 kbps+, probably $700/mo.  T1 direct: 1.544 mbps $1000-2000/mo.  T3 (DS3), negotiable, maybe $10,000/mo.

6. 6 Web Pages Hello Hello Page to Browser Display User Client Body { font-family: …; font-weight: …; } Servers CSS Style Sheet ASPX: Template/Layout Imports System.Data Public Class MyStart … End Class ASPX.vb: Code Database Page request

7. 7 Client Browsers  Basic browsers  Display HTML: Text layout and mark-up  Display basic graphics (GIF and JPEG)  Script (JavaScript)  Can respond to events and handle some tasks at client to provide a faster response.  Heavily used for effects, like roll-overs.  Advanced techniques rely on the Document Object Model (DOM), which is radically different for Netscape and others.  Add-Ins  Macromedia Flash, designed for animation but has its own scripting language.  Java, useful when you need detailed interactive graphics control.  Cell phones and PDAs  Limited screen size (requires different user interface)  Different display technologies

8. 8 Server Technologies  Microsoft.NET  Java 2 Enterprise Edition (J2EE)  Oracle  Sun  IBM, Websphere  BEA and others  Comments  Languages are similar in syntax and structure: Java and C#  Completely different frameworks.  Pages  Database  Communication