I launched a first version of a Telex processor with a web frontend. It is a beta version and currently only processes MVT standard messages.
Some words about the requirements for a flexible interface processor
- Though IATA Telexes are defined by a standard, variations are common because some are produced automatically by other systems and some are created manually, which causes more errors. The processing of telexes, the pattern recognition, must be flexible enough to be able to handle extra inline whitespaces and dots, as well extra lines with free text or extra headers and trailer, eg. now it is more common to receive telexes via email and often some extra email information is added as header before it reaches your system. Customers also might create their own telex standards, meaning the whole message is transported as free text message, but inside the message the customer uses his own syntax for data transmission.
This requires a message interpreter that can be configured for new or non-standard formats on the fly, without the need to change any sourcecode and to redeploy a system.
(I saw a project at one airport where the change of LDM format interpretation would have cost the customer around 10.000 Euro because one of the cargo airlines send messages with an extra header line)
- Other standard messages, such as AFTN, NOTAM or CFMU should be processed by the same engine using the same approach. One interface engine with the flexibility of the scripts covers the various aspects of the different types.
A few words about concept and architecture
Certainly the word ESB sometimes might appear bloated like other IT buzzwords, but it hardly makes sense today to implement distinct own interface systems for every protocol or subsystem type you come across. In a heterogeneous IT landscape like an airport an ESB allows you to easily connect inbound and outbound to a number of other systems via TCPIP, Email, FTP,.. or even talk to other standard systems like SAP, Salesforce.com and so on. We use one connector to talk to the ESB, the rest we orchestrate in the ESB itself. With MULE ESB we have the freedom of an opensource product as well the power of enterprise support. The learning curve for MULE is not too steep.
For the sample of telexes: Sometimes you ‘receive’ telexes by using the auto export function of the Sitatex application and retrieve the files with the messages via FTP, or you receive the messages as email or via a queuing server from a central corporate entrypoint. We can swing over to another source or run in parallel without touching the main system.
- Script Engine
Instead of hardcoding the various formats, we use a Java Script engine executing Groovy Scripts. These scripts, one for each message type, are stored in the DB and can be adjusted or customized easily. The scripts produce an internal XML formatted standard output which easily can be un-marshalled during the downstream processing using proper XSD.
- Data Processing
Whatever requirements you have how to handle the received data. In our sample system here, receive from the web frontend and make it human readable.
Please feel free to drop by http://tools.airtilus.net:8080/AirtilusTelexR and try by yourself. Please note: Do not process confidential as the data is transmitted unsecured and might be stored (to improve the quality). This is NOT a commercial offering but a technology showcase. There is no warranty that the server is available or the processor correct. You can use the example message and modify it, otherwise copy and paste your own message.
The service is currently running on a Amazon EC2 micro instance, performance might decrease with a lot of traffic.
- Summary for errors and rejected messages.
- For the next versions I will add some of the other available telex types will follow such as LDM and CPM.
- Add AFTN message interpretation.
- Email Reply (send an email to the service and the human readable version is emailed back to the user).