As already mention by the others, the level system seen on servers these days is from third party server-addons, namely Airio. Airio uses some data from LFSworld.net (if you have allowed the data to be shared) aswell as gathering and storing its own data from sessions raced on Airio powered servers.
Your Airio level/rank is divided in two: Globally and host specific points.
The global points is the LFS Experience Index (LFSEI). Any other rank or level/points systems you see online is host specific.
For instance, if you race alot on one specific server, you gain some LFSEI, and some host specific points. If you connect to another server, your LFSEI will follow you there, but you start from scratch gathering any host specific points.
PS. If you have disabled data sharing in your LFSworld profile, these data won't be available to Airio, and your level/rank might be lower than it should be.