Transcript World Wide WAP - Information Systems and Internet Security

Wireless Application
Protocol
Kulesh Shanmugasundaram
[email protected]
Introduction
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History of WAP
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Ericsson develop ITTP for VAS - 1995
Unwired Planet develop HDML, HDTP - 1996
Nokia develop Smart Messaging, TTML – 1997
WAP Forum formed in June 1997
Table of Contents
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Architecture
Protocol Stack
Development
Future of WAP
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Architecture of WAP
WAP!!
WAP!
Encoded Request
HTTP Request
Encoders
&
Decoders
User Agent
Encoded Response
Clients
(handheld device)
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CGI
Scripts
HTTP Response
Gateway
(WAP Server)
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content
Server
(Web Server)
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Architecture of WAP
WT A Server
Web Server
W
M
L
ML
HT
Wireless
Network
WML
M
W
L
WAP Server
HTML-WML Filters
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Architecture of WAP
Internet /
Intranet Etc.
WAP Service
Provider Network
WAP Server
Wireless
Network
ISDN/PRI
RADIUS
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Remote
Access
Server
Mobile
Switching
Center
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Limits…
Limited CPU,
Memory
I’m
Popular!
Limited
Bandwidth
Limited
Display
Limited
Keyboard
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WAP Protocol Stack
Application Layer (WAE)
Session Layer (WSP)
Other Services
&
Applications
Transaction Layer (WTP)
Security Layer (WTLS)
Transport Layer (WDP)
Bearers:
GSM CDMA
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CDPD
IS-136
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iDEN
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WAP Protocol Stack
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Makes applications independent of
bearers and other hardware
External applications and services may
access the layers directly
Modified to allow for
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Lower Bandwidth (9.6kbps – 14.4kbps)
Network latency (6 – 10 seconds on SMS)
Unreliable connections
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Wireless Application
Environment (WAE)
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A micro-browser environment containing
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Addressing Model (URL, URI)
Wireless Markup Language (WML)
WMLScript
Content Formats – WBMP, vCard, vCalendar
WTA User Agent
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Handles wireless devices telephony
functions
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Wireless Session Protocol
(WSP)
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A strip down version of HTTP/1.1 (“B”)
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Maintain session states
Session suspend, resume (long-lived
sessions)
Facilitate reliable & unreliable data push
Protocol feature negotiation
Header caching
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Wireless Transaction Protocol
(WTP)
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Three types of transactions
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Unreliable one-way requests (class 0)
Reliable one-way requests (class 1)
Reliable two-way request-reply (class 2)
Reliability thru [selective] retransmission & delayed acks
PDU concatenation
Asynchronous transactions
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Wireless Transport Layer
Security (WTLS)
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WTLS is an optional layer
Privacy thru encryption
Data integrity thru MACs
Authentication & nonrepudiation thru
digital certificates
Compression
Elliptic Curve Cryptography (ECC)
http://www.certicom.com/
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Wireless Datagram Protocol
(WDP)
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Offers consistent services to upper layers and
communicate transparently over one of the
available bearer services.
Global interoperability can be achieved using
mediating gateways.
IP & IPLess bearers
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Use UDP for IP bearers (eg. CSD)
Follow WAP Specs for others (GSM)
Error handling done by WCMP
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How limits are handled
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Low bandwidth
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High latency
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WML contents are encoded
WSP supports long-lived sessions
WTP designed to minimize number of transactions
Asynchronous request/response model
Client side programming using WMLScript
WTA repositories
Unreliable connection
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WSP supports long-lived sessions to resume efficiently
Selective retransmission of segments by WTP
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How limits are handled (cont…)
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Small Display
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Limited input facilities
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Decks and card makes inter-page navigation easier
Limited memory & CPU
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Decks and card interface
Binary encoding of WML contents saves memory
Limited set of functionality of WMLScript & libraries
Limited battery power
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Minimizing bandwidth needs
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What is in a client?
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WML
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WMLScript
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A lightweight markup language, similar to
HTML but optimized for hand-held devices
Similar to ECMA Script, enhanced with
libraries
Micro-browser
WTA Libraries
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What is in a WAP Server?
SNMP
Java
M
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N
A
G
E
M
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N
T
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Logging
Billing
Data
Sub. DB
Subscriber
Data
Encoders
Context Manager
Server
Applications
WSP
WTP
HTTP
WTLS
WDP/Adaptation
TCP/IP
Bearers
Internet/FW
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What is in a WAP Server?
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WAP Server bridges the mobile handheld device and rest of the world
Usually it is the homepage of the
browser in a handheld device
WML/HTML Filters
Two types of deployment strategies can
be used (figures)
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What does the web server do?
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Nothing unusual
How to make your web server serve
WAP contents. Define these MIME types
Document type
MIME type
Plain WML documents
text/vnd.wap.wml
Wireless Bitmap Images
image/vnd.wap.wbmp
Compiled WML documentsapplication/vnd.wap.wmlc
WMLScripts
text/vnd.wap.wmlscript
Compiled WML Scripts
application/vnd.wap.wmlscriptc
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Typical extension
.wml
.wbmp
.wmlc
.wmls
.wmlsc
You are ready to serve WAP contents!
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WAP Development
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Development on the client side:
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Limited memory, limited display, limited
power, limited everything…
Most programming is done with WML,
WMLScript, WTAI
Some in ANSI C
A Sample code
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WML: “Howdy World!”
<?xml version=“1.0”?>
<!DOCTYPE WML PUBLIC “-//WAPFORUM//DTD WML 1.1//EN”
http://www.wapforum.org/DTD/wml_1.1.xml>
<wml>
<card>
<p>
Howdy World!
</p>
</card>
</wml>
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WAP Development
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Development on server side:
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Most of the development is done at WAP
Server
Vendor dependent development tools
Java Servlets, C/C++ & PERL
Usually APIs are provided
Network operator may develop VAS on
WTA Server
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WAP Development
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What can we develop?
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Tetris, yay!
Push technology at its best
Access to your intranet
Advanced telephony features using WTA
Remotely control your house (MultiSens)
Anything you wish!
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Future of WAP
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Internet on a cell-phone
Speech API
Vendor independent telephony services
Streaming media
Multicasting
Downloadable applications
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Resources
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http://www.wapforum.com
http://www.phone.com
Nokia WAP Developer Forum
http://www.forum.nokia.com/developers/wap/
The Independent WAP/WML FAQ
http://wap.colorline.no/wap-faq/
Yahoo!
http://search.yahoo.com/bin/search?p=WAP
WAP Portal
http://www.wapdrive.net/
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The End
The End
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