3) Session Layer:-
- It deals with network dialogue control for establishment of session for transmitting the data. Hence, it deals with connection establishment, maintenance and connection termination.
IP Address-
IPV4:-32 bits
IPV6:-128 bits
4) Transport Layer:-
- Act as a mediator or a bridge between network support layer and user support layer.
- It is responsible for process to process delivery of data i.e segments on the basis of port numbers or service point address.
- It can provide connection less as well as connection oriented services.
- If connection oriented then it will provides end to end error control flow control and connection control. Hence, reliable but slow.
Network Support Layer:-
- Network Layer, Data Link Layer and Physical layer are known as network support layer because they deals with the physical aspects like segmentation of the data in small data units their address and synchronization.
- These can be Software or Hardware but the the physical layer is truly hardware in nature.
Electronics Tutorial 