Jimmy's Blog » Technology

Jimmy’s Blog – ISO 8583 Tutorial – Introduction for Beginners

jimmy — Mon, 25 Jul 2011 09:46:23 +0000

ISO 8583 Tutorial article

Introduction

Lately I’ve handle several financial project that allow me to understand bank and financial transaction better.
All (or most?) financial transaction is using ISO 8583 standard, which at first I thought is a complicated standard. But after learn and see how it implemented it’s not as complex as I thought.
In this post I will try to explain (based on my experience before I go deeper on the programming side.

Although it’s a ’standard’ I see that’s many variant for the detail implementation of ISO 8583.

Financial transaction is communication between 2 system through socket connection.
After connection established, each system can send message in ISO 8583 format which commonly will be request and the other system will response.
From my experience the communication will be start with sign on and then the financial transactions.
Periodically an echo message is send to make sure the other system is still alive.

If I break down the flow:

System A open connection to System B (through specific IP and Port).
Connection established.
System A send Sign-On request message.
System B send Sign-on response message.
System A will start send Echo request message periodically (e.g every 1 minute).
System B will send Echo response message when receive Echo request message.
When financial transaction happen, System A will send Transaction request message.
Then System B will send Transaction response message.
If something wrong happen (usually timeout so System A didn’t get the response), System A will send Reversal request message to cancel the previous transaction.
System B will send Reversal response message.

I hope my explaination give clear basic understanding about the flow.
Next the question will be what’s this ISO 8583 message looks like.
We can separate the message into 3 parts:

Message Type Identifier
Bitmaps
Data Elements

ISO8583 - structure

Message Type Identifier

Message Type Identifier or MTI is 4 digits numeric that describe the message type. It will explain the message function.
Commonly used:
- 02xx : Financial Message (e.g 0200 for request, 0210 for response)
- 04xx : Reversal Message (e.g 0400 for request, 0410 for response)
- 08xx : Network Management Message (e.g 0800 for request, 0810 for response)
* I found more detail & complete list at wikipedia

Bitmaps

Bitmaps is field that contain information about which data element is presence or absence. Based on the variant it could be 16 hexadecimal characters.
An example will make it clear.

The bitmap is:

B220000000100000

If we break down to binary (I hope you understand how to convert hexadecimal to binary:) :

1011001000100000000000000000000000000000000100000000000000000000

Since I’m nice I create graphical illustration.

Bitmap sample

You can see that in this bitmap it explain that data element in the message is 1, 3, 4, 7, 11.
There’s special meaning of first bit of bitmap, if it has value of 1 that mean there’s secondary bitmap.
And what the hell is this secondary bitmap?
Since 16 hexadecimal characters will can only contain info of 64 data element, some transactions contain data element number 64 – 128. That mean the 16 hexadecimal characters is not sufficient.
With set the first bit to ‘1′ that will inform there’s additional bitmap, which is another 16 hexadecimal characters.
So in this case the full bitmap example should be:
B2200000001000000000000000800000
Convert to binary:
10110010001000000000000000000000000000000001000000000000000000000000000000000000000000000000000000000000100000000000000000000000
From the bitmap, data element presence in the message : 3, 4, 7, 11, 105.

Sample Bitmap complete

Data Elements

Data Elements is the essense of the whole ISO message, contain information about the transaction (transaction type, amount, customer id, etc).
Each data element have their on format, attribute and length.
Each data element number also have standard purpose, for example DE #4 is transaction amount.
I will explain based on the example above, since this is only introduction I don’t want to confuse beginner reader. In wikipedia there’s full list.
For our examples, the data element list:

#3 – Processing code – n 6
#4 – Transaction amount – n 12
#7 – Transmission date & time – n 10
#11 – Systems trace audit number – n 6
#44 – Additional response data – an ..25
#105 – Reserved for ISO use – ans …999

To make it practical let’s just use example.
We want to send :

DE #3 : 201234
DE #4 : 10000
DE #7 : 1107221830
DE #11 : 123456
DE #44 : A5DFGR
DE #105 : ABCDEFGHIJ 1234567890

Using above value, the data in data elements :

ISO8583 - de

Based on the type each value will be formatted.

a : alpha (including blanks)
n : numeric value
s : special characters
x (no dot) : length is x (fixed)
.x (one dot) : max length is x (1 digit in front as length info)
..xx (two dot) : max length is xx (2 digit in front as length info)
…xxx (three dot) : max length is xxx (3 digit in front as length info)

ISO Message

From above examples the whole ISO message will be :

0200B2200000001000000000000000800000201234000000010000110722183012345606A5DFGR021ABCDEFGHIJ 1234567890

Conclusion

Ok. This article already long enough
Actually I always prefer short article, but on this case it’s cannot be to short.
Anyway, I hope this article is clear enough for you.

Like always, just drop question in the comment if you confused.

Next I will write article about implementing ISO 8583 using JPOS library.

Basic LWUIT tutorial/sample with Eclipse Pulsar

jimmy — Sat, 17 Apr 2010 17:31:41 +0000

I was really want to try LWUIT since several months ago. It’s look promising and it’s developed by SUN so I think every Java ME developer should take a look on this technology.
I’m also still new in LWUIT so there won’t be a lot that I can share for now, but at least I will show you a basic demonstration of how to use Form, Label, Command, and 3D Form transition (sound cool huh :p)

REQUIREMENT

What you need:

LWUIT
Eclipse Pulsa
Emulator like Sun WTK
Know basic Java ME programming

CONFIGURE ECLIPSE

First you need to setup your emulator in Eclipse.
Run your Eclipse and select at the menu : Window – Preferences
Select : Java ME – Device Management – click Import
Then browse to your emulator folder, it will scan and give you option to add it to your device list.

Eclipse Pulsar Device Management

*I found that the automatic javadoc folder detection for each jar library is not all correct (I’m using Ubuntu 9.04, WTK 2.5.1)

CREATE NEW MIDlet PROJECT & CONFIGURE

Ok, now we ready to create the new project.
I assume you already know how to use Eclipse properly, create a new MIDlet Project there you will select your default emulator you want to use in the project, MIDP – CLDC version, etc.
After the new project created we gonna add the LWUIT library to the project.
Right click on the project (at package explorer) and select Properties.
Select ‘Java Build Path’ and tab ‘Libraries’ then click ‘Add External Jars’ and browse to select where your LWUIT jar is. (It will be on the lib folder where you extract you LWUIT zip)

MIDlet Project Properties

You will see the LWUIT.jar shown.
Select tab ‘Order and Export’, check the LWUIT.jar library so it will be included in our application jar.

Pulsa MIDlet project order and export

One of the cool thing about LWUIT is theme feature, you can see there’s ResourceEditor in LWUIT’s ‘util’ folder it’s for editing theme.
Let’s use default theme from the package. Copy file that located at ./LWUITDemo/src/LWUITtheme.res to our project ‘res’ folder (you can drag ‘n drop it to Eclipse).

THE CODING

Now we finally get to real coding.
Add a new MIDlet to the project. In my example I will create BasicForm Class:

package gnu.jimmy.blog.lwuit;
 
import java.io.IOException;
 
import javax.microedition.midlet.MIDlet;
import javax.microedition.midlet.MIDletStateChangeException;
 
import com.sun.lwuit.Command;
import com.sun.lwuit.Display;
import com.sun.lwuit.Form;
import com.sun.lwuit.Label;
import com.sun.lwuit.animations.CommonTransitions;
import com.sun.lwuit.animations.Transition3D;
import com.sun.lwuit.events.ActionEvent;
import com.sun.lwuit.events.ActionListener;
import com.sun.lwuit.layouts.BorderLayout;
import com.sun.lwuit.layouts.BoxLayout;
import com.sun.lwuit.plaf.UIManager;
import com.sun.lwuit.util.Resources;
 
public class BasicForm extends MIDlet implements ActionListener {
 
	private Form form1;
	private Form form2;
 
	private Command cmdRotate = new Command("Rotate");
	private Command cmdSlide = new Command("Slide");
	private Command cmdExit = new Command("Exit");
 
	public BasicForm() {
		//Initialize the LWUIT
		Display.init(this);
	}
 
	protected void startApp() throws MIDletStateChangeException {
		//Load the Theme
		Resources r;
		try {
			r = Resources.open("/LWUITtheme.res");
			UIManager.getInstance().
			setThemeProps(r.getTheme("LWUITDefault"));
		} catch (IOException e) {
			e.printStackTrace();
		}
 
		//Setup Form 1
		form1 = new Form("Form 1");
		form1.setLayout(new BorderLayout());
		form1.addComponent(BorderLayout.NORTH, new Label("My First Form"));
		form1.addComponent(BorderLayout.WEST, new Label("WEST"));
		form1.addComponent(BorderLayout.CENTER, new Label("CENTER"));
		form1.addComponent(BorderLayout.EAST, new Label("EAST"));
		form1.addComponent(BorderLayout.SOUTH, new Label("Click Rotate"));
		form1.addCommand(cmdRotate);
		form1.addCommand(cmdExit);
		form1.addCommandListener(this);
		form1.setTransitionInAnimator(CommonTransitions.createSlide(CommonTransitions.SLIDE_HORIZONTAL, true, 1000));
 
		//Setup Form 2
		form2 = new Form("Form 2");
		form2.setLayout(new BoxLayout(BoxLayout.Y_AXIS));
		form2.addComponent(0,null,new Label("This is the second Form"));
		form2.addCommand(cmdSlide);
		form2.addCommand(cmdExit);
		form2.addCommandListener(this);
		form2.setTransitionInAnimator(Transition3D.createCube(1000, true));
 
		form1.show();
	}
 
	public void actionPerformed(ActionEvent evt) {
		//check which command cliked
		if (evt.getCommand()==cmdExit) {
			notifyDestroyed();
		} else if (evt.getCommand()==cmdRotate) {
			form2.show();
		} else if (evt.getCommand()==cmdSlide) {
			form1.show();
		}
	}
 
	protected void destroyApp(boolean unconditional) throws MIDletStateChangeException {
	}
 
	protected void pauseApp() {
	}
 
}

Try to run the class.
It should display a form and when you click the left softkey change to the second form with cube rotate effect.
When you click the left softkey again it will go back to first form with slide effect.

LWUIT sample

NOTE
* all UI classes are from package com.sun.lwuit don’t import the WTK default.
* Display.init function (the one I put in constructor) needed to execute first before initializing Forms
* Theme need to be load first before initializing Forms
* Transition3D will require M3G, so if you want to test it on real phone make sure your phone support it. If not you can just change the Transition3D to CommonTransition.

ENDING

If you have prompt to follow the tutorial just drop me a comment here.

Cheers

Blackberry sending delivered notification email

jimmy — Fri, 26 Jun 2009 15:27:40 +0000

I just realize that when sending to blackberry device when the email received on blackberry and the sender request delivered notification, it will automatically send delivered notification back to the sender.

And there’s no option to disable this.
Maybe it’s like a ‘feature’, but in my opinion it’s suck to cannot select whether we want to sent this delivered notification or not.
For spammer this could be good ‘feature’ since they will know which email still actively receiving their spam.

In my blackberry curve there’s only option to disable ‘read notification’, which located at message – options – email settings.
But read notification is not delivered notification, when I disable sending read notification still the blackberry sending delivered notification automatically.
This is sucks, anyone know how to solve this issue?

Unknown winmail.dat attachment in email

jimmy — Tue, 29 Jul 2008 04:59:27 +0000

From my colleague I received an email but with unknown type : winmail.dat
He should send me office document.
I asked him to sent it again, he forwarded the email again but I still received winmail.dat in attachment.

After googling about this I found out that winmail.dat is generated by Outlook (I using thunderbird).
From About.com :

It’s Outlook’s fault, in a way. Or the recipient’s email client’s. If Outlook sends a message using the RTF format (which is not very common outside Outlook) for bold text and other text enhancements, it includes the formatting commands in the winmail.dat file. Receiving email clients that do not understand the code therein display it as a stale attachment. To make matters worse, Outlook may also pack other, regular file attachments in the winmail.dat file.

Fortunately, you can get rid of winmail.dat altogether by making sure Outlook does not even try to send mail using RTF.

And there’s also a way to disable this feature on Outlook. You can open it for more detail.
I would focus on how non-Outlook user can handle this format.
I know I can not ask all Outlook user who sent me attachment to turn off this feature.

So I search a program to open this content type “application/ms-tnef”.
I encounter this good console program : WMdecode
You just need to extract this. When running the program it’ll search winmail.dat in current folder and extract it.
The program working great although it just console application, no GUI.

Other tool I search is add on for Thunderbird.
I found : LookOut
This add on will automatically decode the winmail.dat
Also working great but it won’t decode winmail.dat in emails that you received before installing the add-on.
So I think it’ll only decode winmail.dat on new email received.

Cheers

Microsoft + Yahoo = ?

jimmy — Tue, 05 Feb 2008 04:53:44 +0000

Microsoft planning to buy Yahoo for $44.6 billion. Until now Yahoo hasn’t give final answer it.
I’m wondering why do Microsoft want to buy Yahoo, is it for fighting Google?
Or Microsoft just want to kill one of his rival.

Let’s see
IM : Microsoft has Windows Live Messenger, Yahoo has Yahoo Messenger.
Search Engine : Microsoft has Live Search, Yahoo has it’s own search engine.
Email : Microsoft has Windows Live Hotmail, Yahoo has Yahoo Mail.

Let’s wait for Yahoo’s final answer.
And how will Google respond about this

VAS (Value-Added Service) introduction

jimmy — Wed, 30 May 2007 09:59:29 +0000

Untuk yang bergelut di dunia Content Provider mungkin istilah VAS / VASP mungkin tidak asing lagi.
Buat yang ngerti tentang VAS ini maka mengutip dari Wikipedia.org :

A value-added service (VAS) is a telecommunications industry term for non-core services or, in short, all services beyond standard voice calls. On a conceptual level, value-added services add value to the standard service offering, spurring the subscriber to use their phone more and allowing the operator to drive up their ARPU. For mobile phones, while technologies like SMS, MMS and GPRS are usually considered value-added services, a distinction may also be made between standard (peer-to-peer) content and premium-charged content.

Value-added services are supplied either in-house by the mobile network operator value-added service provider (VASP). VASPs typically connect to the operator using protocols like Short message peer-to-peer protocol short message service centre (SMSC) or, increasingly, to a messaging gateway that allows the operator to control and charge of the content better. themselves or by a third-party (SMPP), connecting either directly to the short message service centre (SMSC) or, increasingly, to a messaging gateway that allows the operator to control and charge of the content better.

Singkatnya para Content Provider (CP) membuat layanan dengan bekerja sama dengan operator dan berkomunikasi dengan protocol tertentu yang disepakati.
Dengan demikian maka CP dapat memberikan layanan kepada pengguna ponsel dan melakukan charging sesuai layanan tersebut.

Layanan-layanan yang populer saat ini:

Download wallpaper/image
Download ringtone/music
Quiz berhadiah
Ringbacktone (VAS yang palink populer/menguntungkan didunia?)
Download aplikasi/game mobile
Dll -> Layanan-layanan unik lainnya

Demikian pengenalan mengenai VAS untuk hari ini ^^

Jimmy’s Blog – ISO 8583 Tutorial – Introduction for Beginners