OSI concepts are still important, even if none of the layers map to a specific set of protocols and things are blurry near layer 1 and 2.
For example, the fact that presentation and application are separate layers, and that compression/encryption are better in their own layer (presentation) rather than totally integrated in the application.
The OSI presentation layer has nothing to do with compression nor encryption. The top three layers of OSI were much more about modelling mainframe terminal applications than anything modern.
> For example, the fact that presentation and application are separate layers, and that compression/encryption are better in their own layer (presentation) rather than totally integrated in the application.
CRIME attack enters the chat
Compression is not better in its own layer. See the CRIME attack on TLS compression.
Encryption is better at as low an end-to-end layer as possible so that we can have a hope that we can off-load the work to hardware.
For example, the fact that presentation and application are separate layers, and that compression/encryption are better in their own layer (presentation) rather than totally integrated in the application.