Which of the following functions is not performed at layer 6 of the osi model? ( select one of the four options)

routing of the message

encryption

compression

converting the message to a format that is understood by the destination

 The function that is NOT performed at the layer 6 of the OSI model from the options presented, is the first one: Routing of the message.

Explanation:

In the OSI model, Layer 6 is called the Presentation Layer, and is basically responsible of taking the message forwarded by one Application Layer protocol (like HTTP) and formatting it a way that can be uniquely decoded at his intended destination.

This processes can include Encryption and Compression, among others.

So, Layer 6 is not responsible for routing the message (this is a function of the Layer 3, the Network Layer).