In message , at 08:55:28 on
Thu, 28 May 2009, Graham Harrison
remarked:
I've actually seen transaction logs showing the same authorisation
request being sent 3 or 4 times in which case you have to think "no
wonder the guy has no available credit left".

It's a pity the system wasn't designed with a mechanism to de-dupe
multiple attempted identical transactions. The originating system giving
them a unique reference number, re-used after a "no reply" would
suffice. There would then be a way to debug the few remaining problem
scenarios, rather than simply having everyone wring their hands and
point at the other guy.
--
Roland Perry