Net-Centric Computing Content Formats

Net-Centric ComputingContent Formats

2110472 Computer Networks

Natawut Nupairoj, Ph.D.

Department of Computer Engineering

Chulalongkorn University

Net-Centric Computing: Data Formats Natawut Nupairoj, Ph.D.

“Garbage In, Garbage Out.”


Outline

Content Formats Overview. MIME – email contents. EDI – business document contents. XML – generic contents.


Overview

Net-Centric Applications require Networks: a road, an express way

Internet, Intranet, proprietary networks, … Delivery protocols: a mail man, a messager

HTTP, SMTP, TCP/IP, … Content formats: a message

HTML, MIME, EDI, XML, …


Standard Email Contents

RFC 822 – ASCII only

From: [email protected]: [email protected]: MIME demo.

This email is to inform you that…

Header

One blank line

Body (ASCII only)


MIME

Multipurpose Internet Mail Extension RFC 2045 / 2046. Allow non-ASCII data in email contents. “Attachments”.

Three important features Identify type of content. Encode binary-format data into ASCII-format. Multiple attachments.


MIME – Identify Content Type

“Content-Type:” headerContent-Type: type/subtype; parameters

Types Text: text/plain. Image: image/jpeg, image/gif. Audio: audio/basic. Video: video/mpeg, video/quicktime. Application: application/zip. Multiple parts: multipart/mixed.


MIME – Content Encoding

“Content-Transfer-Encoding:” headerContent-Transfer-Encoding: encoding_scheme

Base64 Use ASCII characters to represent binary data. Group data into 6-bit.

0 … 25 ‘A’ … ’Z’

26 … 51 ‘a’ … ‘z’

52 … 61 ‘0’ … ‘9’

62 ‘+’

63 ‘/’


MIME – ExampleFrom: [email protected]: [email protected]: class photoMIME-Version: 1.0Content-Type: multipart/mixed; Boundary=ABCDEF12345

--ABCDEF12345Dear class,Here are the photos …--ABCDEF12345Content-Transfer-Encoding: base64Content-Type:image/gif

Base64 encoded data ....... . . . . . . . . .


EDI

How companies exchange documents Normal mail (snail mail). Fax. Email.

Example: ABC department store sends an order form to

XYZ cloth manufacture via fax. Problems ?


EDI: Electronic Data Interchange

“Intercompany computer-to-computer communication of standard business transactions in a standard format.”


EDI

Standards ANSI X12. UN/EDIFACT.

Who use it ? Import/Export: Thai Customs. Supply Chain: retail stores and suppliers. Shipping and Freight: shipping company and

shipyards.


EDI – How it works

Buyer

ValueAdded

Network

VANProvider

VANProvider

P/O(APP1format)

Purchasingapplication

APP1

TranslatorMappingDefinition

EDIStandard

File

Seller

MappingDefinition

EDIStandard

File

Translator

P/O(APP2format)

Purchasingapplication

APP2


EDI – Sample EDI FileISA*00* *00* *08*61112500TST *01*DEMO WU000003

*970911*1039*U00302000009561*0*P? GS*PO*611125001I*WU000003 *970911*1039*9784*X*003020 ST*850*397822 BEG*00*RE*194743**970911 REF*AH*M109 REF*DP*641 REF*IA*000100685 DTM*010*970918 N1*BY*92*1287 Nl*ST*92*87447 N1*ZZ*992*1287 PO1*1*1*EA*13.33**CB*80211*IZ*364*UP*71837927164l PO1*1*2*EA*13.33**CB*80211*IZ*382*UP*718379271573 PO1*1*3*EA*13.33**CB*80213*IZ*320*UP*718379271497 PO1*1*4*EA*13.33**CB*80215*IZ*360*UP*718379271848 PO1*1*5*EA*13.33**CB*80215*IZ*364*UP*718379271005 CTT*25 SE*36*397822 GE*1*9784 IEA*1*000009561


Extensible Markup Language

We will use slides “Introduction to XML” by Hall and Brown.


Sample PO in EDI FormatISA*00* *00* *08*61112500TST *01*DEMO WU000003

*970911*1039*U00302000009561*0*P? GS*PO*611125001I*WU000003 *970911*1039*9784*X*003020 ST*850*397822 BEG*00*RE*194743**970911 REF*AH*M109 REF*DP*641 REF*IA*000100685 DTM*010*970918 N1*BY*92*1287 Nl*ST*92*87447 N1*ZZ*992*1287 PO1*1*1*EA*13.33**CB*80211*IZ*364*UP*71837927164l PO1*1*2*EA*13.33**CB*80211*IZ*382*UP*718379271573 PO1*1*3*EA*13.33**CB*80213*IZ*320*UP*718379271497 PO1*1*4*EA*13.33**CB*80215*IZ*360*UP*718379271848 PO1*1*5*EA*13.33**CB*80215*IZ*364*UP*718379271005 CTT*25 SE*36*397822 GE*1*9784 IEA*1*000009561


Sample PO in XML Format<?xml version = "1.0"?><purchase-order> <header> <po-number>1234</po-number> <date>l999-02-08</date><time>14:05</time> </header> <billing> <company>XMLSolutions</company>

<address> <street>601 Pennsylvania Ave. NW</street> ...

</address> </billing> <order items="1" >

<item> <reference>097251</reference> <description>Widgets</description> <quantity>4</quantity> <unit-price>11.99</unit-price> <price>47.96</price></item>...

</order> ...</purchase-order>


Summary

Content formats are very important for Net-Centric Applications.

XML is a very important standard Flexible and extensible. Both human and machine readable. Lots of tools. Being used in many areas

Data formats. Programming interface description. RPC protocol formats.


Summary

Other data formats CSV. Fixed-column format. Application-dependent formats. XML-based formats: ebXML.


References

Kurose and Ross, Computer Networking: A Top-Down Approach Featuring the Internet, Addison Wesley Longman, 2001.

R. Morin, “Howto Base64”, http://www.kbcafe.com/articles/base64.html.

P. Sokol, From EDI to Electronic Commerce: A Business Initiative, McGraw-Hill, 1995.


References

M. Johnson, “XML for the absolute beginner ”, Javaworld, April 1999, http://www.javaworld.com/javaworld/jw-04-1999/jw-04-xml.html.

W3C, “XML Tutorial”, http://www.w3schools.com/xml/default.asp.

M. Hall and L. Brown, “Introduction to XML”, 2001, http://www.corewebprogramming.com.

Documents

Net-Centric Computing Content Formats