Network Layer of OSI Model

Network Layer

• The network layer handles communication with device on logically separate networks that are connected to form internetworks.
   
• Because internetworks can be large and can be constructed of different types of networks.
   
• The network layer utilizes algorithm that guide packets from their source to their destination networks.
   
• Within the network layer each network in the internetworks is assigned a network address that is used to route packets.
   
• The network layer manages the process of addressing [networking] and delivering packets on internetworks.
   
• On the layer network, it is impractical to deliver network data solely by means of physical address.
   
• Larger networks require a means of routing and filtering packets to reduce network traffic and minimize transmission time.
   
• The network layer uses logical network address to route packets to specific networks on an internet layer.
   
• The network layer also support service address, the operating system on most computers can run several processes at once.
   
• These service addresses are included with the physical and logical network address in the data frame.
   
• Some service address, called well known addresses is universally defined for a given type of networks.

These well known addresses are often used for service that is shared between many different vendors.