A question was asked in a way that made me realize I have never discussed a little used but vital component of all of the older turbojet engines.
Interconnectors are part of the design in cantype combustion sections, and in canannular, so almost all jet engines up until about 1970 or so. There are some notable exceptions, and I want you to mention them in the comments.

The engine could not run without these, but they are only functional during startup. While running, they do nothing.