We
transfer files in our back end using FTP and have a very eloquent
solution.
We
transfer a .DAT file and a .DONE file containing the byte count of the
data
file after.
If
the .DONE file, byte count does not agree with the .DAT file or the
.DONE
file is not present, then the condition is trapped such that an
investigation
can be commenced to determine the source of the issue.
We
have been using this scheme for about three years with very good
hands
free results. It virtually ensures that the whole file got there
in
one piece. Our processes are set to test and trap the existence of
both
as a condition to process as well as matching the byte count contained
in
the .DONE file with the actual byte length of the .DAT file
I
will give you that this is an in-house standard, but it would not be
a
bad idea to use via the internet for the same purposes. It provides
simplicity
with a virtually robust FTP environment that allows for trapping
the
problems when they occur.
the
object is that this file name for both are the same as in the
following.
somethingtoprocess.DAT
This
file contains the data as meant for processing on the target system.
the
data can be EDI, Proprietary formats, XML or what ever....
somethingtoprocess.DONE
Contains
the information pertaining to the .DAT file above including a count of
the
number of bytes transmitted across the connection as the first record in the
file.
The
net result is that the presence of the .DONE file indicates that the transfer
of the
first
file succeeded, because it is moved if the first FTP put succeeded. A match on
the
byte
count contained in the .DONE file and the actual length of the .DAT file
ensures that
the
total .DAT file made it to the target system. Both checks must be passed to
process the
file.
Once
the process has occurred, the files are archived in another directory for
backup and this
removes
them from being processed a second subsequent time by another later
process.
As
I stated in my opening remarks, this solution is very simple to accomplish. It
virtually
eliminates
the inherent problems with FTP.
Regards,
Mark
-----Original
Message-----
From:
[EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]
Sent:
Saturday, May 05, 2001 5:04 PM
To:
[EMAIL PROTECTED]
Subject:
Re: EDI over the Internet
The
hardest part is writing the scripts to drive FTP *reliably*. For
example,
depending on your FTP client, an rc=0 from the FTP command may
*not*
mean that the transfer was successful. It may just mean that the
FTP
client
didn't trigger a dump. In the general case, the safest thing to do
is
to is to programmatically examine the FTP output for the message
that
indicates
a successful transfer.
If
you are doing an mput or an mget, in the case of a problem you have
to
programmatically
figure out which files were successfully transferred so
that
you know where to restart.
When
doing a get or mget, you have to figure out a way to avoid pulling
the
same
file twice on two different FTP sessions. One obvious way is to
delete
the
file from the source remote directory after a successful get.
You
also need to watch out for what I call the "FTP partial file
transfer
syndrome"
. I.e., you have to take steps to ensure that the system on the
receiving
end of the transfer does not process partially transferred files.
One
way of doing this is to "put" the file to a temporary directory on
the
remote
end, and then to do an "FTP rename" to place the fully transferred
file
into the actual final target directory. That way the receiving
system
can
be assured that everything that it sees in the ultimate target
directory
is
a complete file.
The
GEIS FTP server, for example, is customized to handle the "partial
file
transfer
syndrome" in a special way. It does not assume that an incoming
file
has been completely transferred until the sending FTP client issues
a
subsequent
command after the "put".
In
terms of encryption, a problem with FTP is that there is no standard
method
of dealing with encryption. Some options are:
-
You can not worry about it. You'll probably get away with this. It's
a
matter
of judgement but I personally don't like "probably" over the public
Internet.
-
Use any of a number of commercial FTP products that provide a
customized
client
and server that interact with encryption technology in order to
provide
authentication, data privacy, detection of data alteration, and
non-repudiation.
The one's that I am aware of work well. The problem with
this
approach is that you have to convince your trading partner to
install
the
appropriate commercial client and/or server on their end.
-
Here is one effort of the open source community to wrap FTP (among
other
things)
in SSL: http://www.rickk.com/sslwrap/. The "ssleay" SSL
impementation
is orphan code, so I'd use it with OpenSSL: www.openssl.org.
-
You can encrypt files before transfer using something like PGP, then
decrypt
them again on the receiving end.
Because
there is no standard way of using encryption with FTP, you may end
up
using a multitude of approaches with your multitude of trading
partners.
As
with deciding on an EDI guideline, deciding on a secure FTP approach
is
often
driven by who "needs" the trading partner relationship more. You
would
want to establish what your most preferred approach is, so that you
can
recommend it when the trading partner does not have a preference.
As
has been mentioned by others, most of the major VANs, at least, have
some
sort
of FTP connectivity offering. However, some of them may still
require
that
you use private IP networks rather than the public Internet, because
of
the
above-mentioned chaos regarding encryption using FTP.
--Joe
--
Joseph
Kellett
Legendary
Systems
[EMAIL PROTECTED]
>
-----Original Message-----
>
From: Electronic Data Interchange Issues
>
[mailto:[EMAIL PROTECTED]]On Behalf Of Lois Prather
>
Sent: Friday, May 04, 2001 2:31 PM
>
To: [EMAIL PROTECTED]
>
Subject: Re: EDI over the Internet
>
>
>
http://www.icc.net
>
>
-----Original Message-----
>
From: Electronic Data Interchange Issues
>
[mailto:[EMAIL PROTECTED]]On Behalf Of Arthur Weiner
>
Sent: Wednesday, May 02, 2001 2:17 PM
>
To: [EMAIL PROTECTED]
>
Subject: Re: EDI over the Internet
>
>
>
At my last company (I was Dir. IS) I used FTP to all VANs and
>
dialup direct
>
to Wal-Mart. We had very few problems over the four years
>
that we used the
>
internet. It was on an AS/400 using Harbinger EDI/400 v. 2.11
>
>
------------------------------------------
>
Arthur Weiner
>
(973) 625-0832
>
>
>
>
> -----Original Message-----
>
> From: Electronic Data Interchange Issues
>
> [mailto:[EMAIL PROTECTED]]On Behalf Of Richer, Robert
>
> Sent: Wednesday, May 02, 2001 4:49 PM
>
> To: [EMAIL PROTECTED]
>
> Subject: EDI over the Internet
>
>
>
>
>
> Bonjour everyone!
>
>
>
> I'm new to this list. So may be this question has already
>
> been asked and if
>
> so I'm sorry about that.
>
> Feel free to email me directly if needed.
>
>
>
> I'm just curious to know if any of you are using the Internet
to
>
> send/receive EDI transactions.
>
>
>
> If so, can you let me know how you are doing it (software
>
> used, are you
>
> using encryption, any problem with it, recommendations,
etc....)
>
> I'm looking for a solution that will allow me to send
>
transactions via
>
> Internet for some customers but I still need some kind of
>
> access to the
>
> regular VANs for my trading partners that won't be able to
>
> support EDI on
>
> the Internet.
>
>
>
> Here is my actual setup...
>
> * I'm currently using EDI*Windows 5.2.6 as the EDI s/w
>
> * I'm running it on an NT Alpha (client/server).
>
> * My communication s/w is Cleo
>
>
>
>
>
> Any information will be appreciate,
>
>
>
> Thanks in advance,
>
>
>
>
>
> Robert Richer
>
> Coordonnateur Commerce Électronique
>
> Electronic Commerce Coordinator
>
> IPEX Inc.
>
> Édifice du Port de Montréal / Port of Montreal
Building
>
> Aile 3, 1ier étage, Cité du Havre / Wing 3, 1st floor, Cite
du Havre
>
> Montréal, Qc / Montreal, Qc
>
> H3C 3R5
>
>
>
> Tél.: (514) 861-7221 ext.: 233
>
> 1-800-363-2620
>
> Fax:(514) 861-4188
>
> Internet : [EMAIL PROTECTED]
>
> WWW: www.ipexinc.com
>
>
>
> To contact the list owner: mailto:[EMAIL PROTECTED]
>
> Archives at
http://www.mail-archive.com/edi-l%40listserv.ucop.edu/
>
>
>
>
>
>
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>
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>
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>
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>
>
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=======================================================================
To
contact the list owner: mailto:[EMAIL PROTECTED]
Archives
at http://www.mail-archive.com/edi-l%40listserv.ucop.edu/
- Re: EDI over the Internet Ginny Crane
- Re: EDI over the Internet John McPherson
- Re: EDI over the Internet Abellana, Chris
- Re: EDI over the Internet Foster, Dave
- EDI over the Internet Richer, Robert
- Re: EDI over the Internet Arthur Weiner
- Re: EDI over the Internet Lois Prather
- Re: EDI over the Internet William Wheeler
- Re: EDI over the Internet Arthur Weiner
- Re: EDI over the Internet Mark Kusiak
- Re: EDI over the Internet Jim Divoky