Knowledge Base

Enter search queries below or use the tag links to the right to browse the knowledge base by category (Show All Tags).

How do incompatibilities get introduced from one release to another?

While maintaining compatibility between versions is a high priority, issues still arise as a result of upgrading between versions from time to time. This happens with all software, but is particularly common when dealing with network file transfer protocols like FTP, FTPS, SFTP, HTTP, and HTTPS.

A question that we often hear is, "If I was able to connect, download, upload, etc. with a particular server with version X of Robo-FTP, then why does this no longer work with version Y? Doesn't that mean version Y is broken?"

The answer is, "Not necessarily."

Robo-FTP's implementation of any particular protocol is a constantly-moving target. Changes to the underlying way the software works can be a result of many different causes, such as:

  • Changes in the protocol specification
  • Need for performance improvement as customer's requirements include more/bigger files
  • Security
  • Operating system changes
  • Improved compatibility with a wider array of servers (which can occasionally break compatibility with particular, individual servers)

For example, version X of Robo-FTP might submit a particular SFTP command a certain way which correctly follows the SFTP spec and happens to be compatible with a particular server. Version Y may, for one or more of the reasons listed above, submit the same command a different way which is also correct, per the spec, but the same server fails to respond to it correctly.

In that case, it may appear that "version X works and version Y is broken," but in reality (at least in this example) the flaw is in the server.

In cases like this, the best solution is to work with the vendor of the server software to see if the issue has been addressed in a more recent release of their software and, if not, isolate the cause of the issue so they can address it.

However, when possible, we also attempt to look for ways to adapt Robo-FTP to meet whatever requirements (security, performance, etc.) lead to the change in question while working around the server issue so the software will continue to be compatible with that server. Doing so typically requires cooperation among our support team, the customer, and the administrator of the server as we work to find a solution.

Article last updated: 2021-11-12

Tags: Robo-FTP