How X.400 works in EDI step by step

 X.400 is a suite of ITU-T (International Telecommunication Union Telecommunication Standardization Sector) recommendations that define a standard for electronic messaging systems. While not as common as some other EDI transmission methods, it can still be used for EDI. Here's a step-by-step guide on how X.400 works in EDI:

==>Step-by-Step X.400 Process

==>1. Document Preparation

1. EDI Document Creation:

   - The sender's system generates an EDI document that needs to be transmitted to the receiver.

==>2. Document Formatting

1. MIME or S/MIME Packaging:

   - The EDI document is optionally packaged into MIME (Multipurpose Internet Mail Extensions) or S/MIME (Secure MIME) format. This format can include additional headers and attachments.

==>3. Addressing

1. Address Configuration:

   - The sender and receiver must have X.400 addresses (also known as O/R (Originator/Recipient) addresses). These addresses are structured hierarchically and may include details like country, organization, organizational unit, and user.

==>4. Document Encryption and Signing (Optional)

1. Digital Signature:

   - If required, the sender's system digitally signs the EDI document using a private key to ensure the authenticity and integrity of the document.

2. Encryption:

   - If required, the document is encrypted using the receiver’s public key to ensure that only the intended recipient can decrypt and read the document.

==>5. Message Submission

1. Message Submission:

   - The sender's Message Transfer Agent (MTA) submits the X.400 message, containing the EDI document, to the local Message Transfer System (MTS).

==>6. Message Transfer

1. MTA Communication:

   - The sender’s MTA forwards the message through the X.400 network, which may involve several intermediate MTAs.

2. Store-and-Forward:

   - X.400 uses a store-and-forward mechanism, where each MTA stores the message temporarily before forwarding it to the next MTA or the final recipient's MTA.

==>7. Message Delivery

1. Recipient MTA:

   - The recipient's MTA receives the message and forwards it to the recipient's Message Store (MS) or User Agent (UA).

==>8. Message Reception

1. Message Retrieval:

   - The recipient's UA retrieves the message from the MS.

2. Document Storage:

   - The EDI document is stored in the recipient’s system for further processing.

==>9. Document Decryption and Verification (If Applicable)

1. Decryption:

   - The recipient's system decrypts the received message using the recipient’s private key.

2. Signature Verification:

   - The recipient’s system verifies the digital signature using the sender’s public key to ensure the document's authenticity and integrity.

==>10. EDI Document Processing

1. Extract EDI Document:

   - The verified and decrypted EDI document is extracted from the X.400 message.

2. EDI Processing:

   - The receiver’s system processes the EDI document according to business rules and requirements.

==>11. Message Disposition Notification (MDN)

1. Generate MDN:

   - If configured, the recipient’s system generates a Message Disposition Notification (MDN) to acknowledge receipt of the message.

2. MDN Transmission:

   - The MDN is sent back through the X.400 network to the sender, following the same MTA communication and store-and-forward mechanism.

==>Summary

X.400 is a robust and secure messaging standard used for transmitting EDI documents. It involves multiple steps, including document preparation, addressing, optional encryption and signing, submission, transfer, delivery, and processing. The X.400 network uses a store-and-forward mechanism to ensure reliable message delivery. Though less commonly used today, X.400 can still provide a secure and structured way to transmit EDI documents between trading partners.