Re: EDI over http?

[Robert Moskowitz <rgm3@xxxxxxxxxxxx>]

At 01:07 PM 6/17/97 -0700, Matthew James Gering wrote:

Ah, here it is.  Your messages came in reverse order to me for some reason...

>Okay, I have evidently missed the obvious then -- what are the obvious
>advantages.
>
>I can think of two advantages:
>
>* Real-Time response
>I question the necessity of this. Could someone please elaborate.

This debate goes on for some time.  But an HTTP exchange can be done in two
flows, throw the ASN to one end in one PUT (HTTP File Upload) and ack comes
back in the reply.  When I only have 3 minutes to turn around an ASN and 1
minute is eaten up by IMS, I care about how chatty SMTP is.

>* Session encryption
>has security advantages over document encryption only.

You need them both.  Or at least doc sig and session or network encrypt.
Yes someone has specified SSL for SMTP, but then the EDI SMTP model is
based on many SMTP MTAs so here SSL would not be end to end like HTTPS.

>And following disadvantages:
>
>* Fault Taulerance
>through the use of multiple MX records, it handles transmission to hosts
>that are not immediately available, routing around network outages and
>unreachable hosts, etc, etc.

An advantage, but for real time, if my hosts are not reachable, I've got
bigger problems.

>* Gateways
>SMTP can be gatewayed through Firewalls, gatewayed to other networks and/or
>converted to other transport mechanisms such as X.400, etc..

HTTP can traverse firewalls also.   Do I care about X.400?  Well maybe OFTP...

>* Congestion
>SMTP is friendlier on the network than HTTP.

It is?  For this usage?  The studies I saw were based on all of those
little HTTP connections.  Those are not the case here.

>* Reliability
>Denial of Service (DoS) attacks against web servers are far too trivial.

And not for SMTP?  Well they are different ones, but I've seen many an
SMTP's /tmp or /var/mail fill up.

>* Efficiency
>SMTP is a much more efficient protocol than HTTP, both in file transfer and
>server load.

SMTP is chatty, HTTP is not.  There are multi-threaded HTTPs out now, is
SENDMAIL?

One very important advantage of HTTP is it is basically a 2-phase
transaction, where as SMTP is a 1-phase.  The work to coordinate the
response to an EDI over SMTP is not needed over HTTP.  They occur on the
same TCP connection.

Another important advantage is third party participation.  Via chained
URLs, I can have, say a bank, involved in the EDI between two partners.  I
suppose that bang paths could do the same thing.

got to run.  Have a good night!




Robert Moskowitz
Chrysler Corporation
(810) 758-8212