What is an EDI protocol ?

The digital transformation of companies is increasing internal digital data flows and inter-company data exchanges. To achieve this, EDI solutions use data exchange protocols. But what is an Electronic Data Interchange (EDI) protocol ?

In this article, find out :

• How an EDI protocol works ;
• The main EDI protocols ;
• The use cases that differentiate them.

What does EDI mean ?

Electronic Data Interchange is the electronic exchange of documents between a company and its trading partners.

All EDI and data integration solutions, such as EAI and ETL, use data exchange protocols that govern the modes and rules of information transmission.

What are these protocols used for ?

These protocols make it possible to :

• Make exchanges more fluid and reliable ;
• No data is altered by lost bytes ;
• The digital file received is the exact image of the file sent.

Electronic Data Interchange (EDI) protocol : definition

For two systems, a sender (client) and a receiver (server), to work together by exchanging messages, it is necessary :

1. Physical communication can be established between the two systems by various means: local network, VPN, VAN network, Intranet, Internet, etc.
2. The data exchanged must be in a format that can be read and interpreted by both client and server: text, CSV, XML, EDIFACT, proprietary format, etc.
3. That the data sent is received without loss of bytes, without error, without duplication and in the order in which it was sent.

A data exchange protocol (EDI) enables this last point to be satisfied. It dictates the rules of communication between the two systems, client and server, and contains a specification of the various rules and procedures to be followed for transmitting and receiving data, and the language codes enabling communication.

How does a data exchange protocol (EDI) work ?

The method used to guarantee a successful data transfer between a sender and a receiver is to return an acknowledgement of receipt, and to send the data again if the acknowledgement does not arrive within the time allowed for acknowledgment.

A data exchange protocol handles all types of data, whatever the format of the messages exchanged. The protocol is a set of formal rules governing :

• Sequencing of byte flows ;
• Time delay between transmission and reception ;
• Error control throughout the network.

How does it work ?

Data is transmitted in packets between sender and receiver.

The role of the protocol is :

• Guarantee that all data packets reach their destination ;
• Guarantee that the file or message received at the end of transmission is readable and interpretable by the receiving business application.

To achieve this, the protocol adds additional information, such as sequence numbers and control elements, to the individual packets transmitted. This information enables the receiving system to check the quality of the data received and to rearrange them in order to reconstitute the message received. It returns an acknowledgement or an error code defined by the protocol to signify “ok” or “transmission failure”.

What’s more, to secure transmissions and protect them from accidental or deliberate data leaks, many protocols add security measures such as authentication and encryption procedures.

To sum up, data exchange protocols enable you to :

• Open a communication session and keep it open ;
• Check that data sent is received ;
• Handle transmission errors and repeat the transmission until the data is received ;
• Implement measures to secure data transfers against data loss and malicious acts: authentication of parties, data encryption.

What protocols are used in EDI ?

Choosing the right data exchange protocol (EDI) means taking into account technical and business environments. Here are the main protocols and methods used in EDI and data integration solutions.

FTP

FTP, File Transfer Protocol, is the native file exchange protocol on TCP/IP networks. Easy to use, it is no longer recommended due to its security weaknesses. However, it is still used internally for manual file transfers, as it is an easy-to-use TCP/IP standard.

FTP/S

File Transfer Protocol Secure is a version of FTP. FTP/S supports TLS (Transport Layer Security) and SSL (Secure Sockets Layer) encryption. This makes FTP transfers secure.

SFTP

Secure File Transfer Protocol uses FTP and SSH, Secure Shell. SSH is used to establish a secure connection tunnel between the client and the server, through which FTP flows. SFTP is recommended to replace FTP for file and EDI message exchanges.

HTTP and HTTP/S

HyperText Transfer Protocol is used primarily for sending and receiving web pages. HHP/S supports SSL/TLS to secure and encrypt Internet transactions.

AS2 and AS4

AS for Applicability Statement, AS2 and AS4 are two protocols used for data exchange over the public Internet.

They are used for EDI transactions. Their advantage is that they enable fast, reliable connections to be established without the need for VAN networks, which are often too costly to use.

But AS2 requires security procedures on both sides to isolate AS2 access: authentication, firewall, DMZ, etc. Unlike AS4, which operates on a push/pull basis, it requires a permanent connection from the EDI message recipient.

AS4 is an evolution of AS2, developed on the basis of Web Services for ebXML messaging services. AS4 features notification and security capabilities, WS-Security, which are absent from AS2.

OFTP, OFTP2

Odette File Transfer Protocol version 2.0 is the latest version of OFTP.

Odette, Organisation for Data Exchange by Tele Transmission in Europe, is the originator of the OFTP protocol. In France, Odette is represented by Galia, Groupement pour l’Amélioration des Liaisons dans l’Industrie Automobile. OFTP2 enables EDI transactions over the public Internet, offering encryption, data compression and support for large files.

The APIs

APIs, Application Programming Interfaces, are programming interfaces that connect :

• applications ;
• software ;
• programs ;
• data sources.

APIs enable interaction and data exchange.

The advantage of APIs is their real-time nature. They can synchronize data, query databases and return status information.

There are two main categories of API :

• Public APIs : made available to all by an organization, administration or company wishing to share applications and data with third parties. These APIs require authentication with a previously communicated key. Open Banking, which emerged with the 2013 DSP2, is based on public APIs that enable banks to share their customer data with other players in the financial system. This means, for example, that companies and individuals can consult all their bank accounts on the same WEB page.

• Partner APIs are reserved for and used by authorized third parties only. Examples : a company shares its customer data with its marketing service provider, a company’s e-commerce site shares its available stock with Amazon.

Today, APIs are used in a wide variety of ways :

• As with e-commerce sites, they are used for stock availability queries, promo code validation and online payment authorization requests ;
• Web services offered by Internet and mobile applications are based on APIs ;
• APIs are also used by EAI, ESB and ETL data integration solutions: reference data queries, real-time data sharing and updates.

Tenor has been an expert in data flow exchange for over 30 years, supporting you in your data management, EDI and e-invoicing projects.