ISO8583:2003 and jPOS

A jPOS Users list member asked how jPOS could be adapted to work with an implementation of the ISO8583 2003 standard.  Murtuza answered that "it should be a matter of creating a new packager defining the field formatter and using it, i.e., define it in XML and use the generic packager to load it for use."

Right.  The Generic Packager gets the "most bang for the buck" by adhering to the 1987 and 1993 standards, which are still the most prevalent ones in field use today.  [The three standards are 1987, 1993 and 2003.  Amongst large authorizers, American Express stands out by being one of the only ones to make the leap even from 1987 to 1993.]  jPOS' GenericPackager has 'out-of-the-box' XML files for the 87 and 93 versions.

Here's some info I put together to further flesh out Murtuza's answer:

In ISO8583:2003, for example, the STAN goes from six bytes to 12 bytes in length.

So, the Generic Packager contains this definition to begin with…

  <isofield
      id="11"
      length="6"
      name="SYSTEM TRACE AUDIT NUMBER"
      pad="true"
      class="org.jpos.iso.IFE_NUMERIC"/>

…and you’d change it to look like this:

  <isofield
      id="11"
      length="12"
      name="SYSTEM TRACE AUDIT NUMBER"
      pad="true"
      class="org.jpos.iso.IFE_NUMERIC"/>

Similarly, you’d make a sweep through the entire packager for all 128 fields (or at least the sub-set “in play” for you).

I’d recommend a ‘two-step sweep’ exercise:

1. Go through the generic packager XML file provided with the jPOS download and adjust those items like the STAN as indicated.  [You can find a list of these changes in “Annex F” of the ISO8583:2003 spec provided by the International Standards Organization.] 
2. Secondly, you’ll want to go through the spec provided by the authorizing organization (or gateway) to you (that’s assuming, of course, that your exercise is to put in place an ISO implementation created by someone else).  When you get into “private use” fields like 62 and 63, the Standards spec gives you only rough guidelines.  You’ll want to see what the authorizer/gateway has done in its implementation.  [Unfortunately, for most of those private use fields, the packager definition will only get you so far.  These private use fields typically have esoteric, proprietary table structures inside of an ‘IFE_LLLCHAR’ (or similar) construction.  In those cases, you’ll need some in-line code to complete the packaging and unpackaging tasks.]

Alejandro posted this follow-up (which provides more clarification on my previous sentence about the need for in-line code in some places): 

There's a twist with composite elements...some of them use standard TLV format and others (71, for example) use a bit-map format.  I believe that it may require the creation of a customized ISOFieldPackager in order to handle these.  I had to do something like that while implementing ANS X9.15 which uses five 32-bits maps.

[NOTE: 'TLV' here refers a 'Table, Length, Value' construction of field contents.]

Comments

[quynhtp]

Hi somebody ...!
I have a problem need somebody helps : I'm using version 1.6.2 JPOS. how I have to using filed 35 ? ( format is ans )