When an exporter's Export-It system performs a communications cycle it will use Windows® Remote Access Service [RAS] to connect a session to the eConnect dial-in server at Syscob's office. When the exporter's machine has logged into the server it will use Windows® “Printer and File Sharing” protocols [SMB over NetBIOS] to copy, with verification, any EDI traffic to be sent to a folder on the server and then retrieve, with verification, any EDI traffic that the server has received on behalf of the exporter — as illustrated in this flow diagram:
Meanwhile, on the eConnect dial-in server at Syscob there are several processes running to monitor DUES activity; including an “EDI relay” task for each exporter that subscribes to the service. Within 30 seconds of the end of an exporter's eConnect session (and at regular intervals chosen to minimize delays at all other times) the exporter's “EDI relay” task, SEDIdial, will convert any EDI traffic sent by the exporter into MIME messages and relay them, via SMTP, to the endpoint agency (AQIS, Customs, et cetera). It will also check, via POP3, for any replies from any agency for the exporter and store them in the exporter's replies folder for retrieval on their next session. The following illustration shows one such cycle for one exporter:
One minute later another “EDI relay” cycle will occur for that same exporter to retrieve any replies to the EDI messages relayed on the first cycle. The cycles for that exporter will repeat at regular intervals, starting at 1 minute and lengthening by 1 minute each cycle (i.e. replies will be checked at 1, 3, 6, 10, 15, 21 and 28 minutes after the last session ends) to a maximum of 30 minutes between cycles for that exporter. Meaning that watching for replies continues to occur throughout the night and across weekends. Should the exporter run another communications cycle then an immediate relay cycle will occur again and the server “EDI relay” interval will be reduced back to 1 minute. This assures minimal delays between when an EDI agency sends a reply and when it is available in the exporter's folder on the server for retrieval.
Syscob bases the charge to our customers for DUES purely on the exporter's traffic and does not charge the user for dial delays, session establishment, protocol overheads, retransmission of errors, transfer validity verification checking or any other overhead associated with their activity. This means that if an exporter transfers a file of 1,537 bytes they will be charged (at 28 cents per kilobyte) for 1,537 bytes. Regardless of how long the session took or how many tries it took to successfully transfer the file (i.e. there is no charge for a transfer that fails or is aborted). And, unlike the X.400 service, there is no “mailbox rental” assessed for months when an exporter does not make use of DUES — offering significant savings to seasonal exporters.