Transcript WAP why another protocol
WAP why another protocol
Johan Montelius [email protected]
Why?
access to phone features limited user interface limited bandwidth long delay
Solutions
• Limit the number of messages – three-way hand shake – client DNS lookup – multiple HTTP requests • Adapt to the phone – black and white – simple navigation – API to access the phone resources
WAP 1.x
HTTP/TCP/IP WSP/WTP/WDP Gateway WML Browser WML Content
WAE WSP WTP WTLS WDP
WAP 1.x
Wireless Application Environment Wireless Session Protocol Wireless Transaction Protocol Wireless Transport Level Security Wireless Datagram Protocol Bearer (GSM, CSD, USSD, CDPD, SMS ..)
WDP
Wireless Datagram Protocol • a transport layer – source and destination port – segmentation and reassembly • implemented on top of several bearers – GSM, GPRS, CDPD, cdmaOne, PHS, DECT, Mobitex, SMS ….
• similar to IP + UDP
Why WDP ~ UDP
• The link from the mobile terminal to the the fixed side of the WDP connection does not contain any routers. • There is no need for flow control, congestion control etc.
WTP
Wireless transaction layer • Unreliable request – used to push information to a mobile terminal • Reliable request – Same as above push + ack • Reliable request and reply – Used by mobile terminal to request information – get + reply + ack • Several transactions in one session
WSP
Wireless Session Protocol • reliable session • suspend resume a session • binary HTTP/1.1
• push content • connection oriented (over WTP) • connectionless (over WDP)
WAE WSP WTP WTLS WDP
The WAP gateway
WAE WSP WTP WTLS WDP WAE HTTP SSL TCP WAE HTTP SSL TCP
WAE WSP WTP WTLS WDP
The security loop hole
WAE WSP WTP WTLS WDP WAE HTTP SSL TCP WAE HTTP SSL TCP
Who should own the gateway
Mobile Operator Content aggregator Service provider
WAE
Wireless Application Environment the browser WML/Script security WIM User profile UaProf access to the phone WTA
WML 1.2
Wireless Markup Language • XML based • One wml-deck consisting of several wml cards.
• Phone adapted navigation • Limited presentation (b/w, no positioning etc.) • WMLScript (ECMAScript ~ JavaScript) • Event based • Variables
WML example
This WAP site is only here as a an experiment.
Why did WAP fail?
Did it fail or did it not live up to the hype?
WAP 2.0
WML2 - XHTML Basic WAE HTTP TLS TCP IP Wireless profiled TCP
Wireless profiled TCP
• Defined in RFC …..
• Header compression • Larger window size • Larger segment size (path MTU discovery) • ….
WAP 2.0 gateway
WAE HTTP TLS TCP* IP TCP* IP * Wireless Profiled TCP TCP IP WAE HTTP TLS TCP IP
WML2 – XHTML Basic
• Anchor images • Positioning of content • Color – gif, jpeg • Style sheets - CSS Mobile profile • check box, radio button • …..