5)The Session Layer
This layer allows users on different machines to establish sessions between them.
Session offer various services including dialog control,token management and synchronization.
6)The Presentation Layer
This layer is concerned with the syntax and semantics of the information transmitted. The presentation layer manages these abstract data structures and allows higher level data structures (eg.banking records) to be defined and exchanged.
This layer contains a variety of protocols that are commonly needed by users.One widely used application protocol is HTTP,which is the basis for the World Wide Web.
Next coming up TCP/IP Model..