The steps in the ExchangeEmdRQ operation are:

• Validation of incoming requests against the current versions of the TTL, WSDL, and XSD files published on Sabre Dev Studio.
• Validation with the ICE/ESSM system whether the request comes from a user authorized to use the EMD Exchange API.
• Retrieval of the EMD presented for exchange via GetTicketingDocument
• Retrieval of the PNR details via GetReservation
• Checking status of EMD coupons using ElectronicDocumentServices
• Application of internal logic to determine the exchange cost
  • For <TransactionInfo requestType="PriceComparison"> requests, the processing stops here and an EMDExchangeRS response XML payload is returned to the requestor.
  • For <TransactionInfo requestType="Fulfill">  requests, the processing continues as follows:
    • Dispensing of a new EMD number by Sabre’s host process, and association to the eTicket
      • Disassociation of old EMD from the eTicket
    • Creation and delivery of an EDIFACT 798 (EMD exchange) message to the carrier so a new EMD can be created in the carrier’s database
    • Creation of a binary payload to be sent to Sabre’s Passenger Service system to create an EMD in Sabre’s database
    • Initiation of downline processes
      • Accounting line creation
      • IUR creation
      • PNR updates:  WTDB*, *T, *AE, etc.

If any of these communication points experience a failure, it results in an XML error response returned in the ExchangeEmdRS response.  If a document has been created in the carrier’s database, the background processes will automatically send an EDIFACT 802 (system cancel) message.

Note: If you wish to void an EMD resulting from an EMD that was exchanged, this may be accomplished using the Sabre green screen format (WV[line number from *T], then repeat to confirm) or the VoidTicketLLSRQ API.  A void using the EMD Exchange API is not supported.