Features of the package level or network layer

The package level or network layer is located on the third level of the hierarchy architecture reference model as shown in Figure.

This layer exists when the network uses a packet level. The functions defined by International standardization in the framework of the reference model are:

• Setting up network connections to route packets. This function is but not an obligation in the packet level, and it is perfectly conceivable to have a connectionless. If the X.25 standard is connection mode, IP, in contrast, works in connectionless mode.

• Supports packet routing and gateways problems for reach another network.

• Multiplexing network connections.

• Supports the segmentation and clustering.

• Packet loss detection and recovery of lost packets. This function is not Mandatory packet level. IP, for example, level protocol packet has no way to recover lost packets.

• Continuation of sequence data provided to the upper layer, but is not an obligation.

• Flow Control, so there is no overflow memories in charge packet transmission.

• Transfer of explicit data (not mandatory).

• Resetting the network connection (not mandatory).

• Quality of service (not mandatory).

• Managing the network layer.