What is the network layer?

The network layer concerns a layer of 3 connecting the seven -layer open system architecture. Algorithms and network protocols are responsible for identifying the optimal path to the route and reliably supply data packets from their source networks to target networks. As part of the OSI conceptual framework, the network layer responds to the requirements of the service from Layer 4, the transport layer and issues the requirements for the service on layer 2, the data connection layer. In practice, it consists of devices, primary routers and mechanisms such as the Internet protocol (IP), necessary to transfer digitally coded signals from source hosts across digital networks - such as the Internet - to target hosts. The key functions of the network layer include addressing, overload control, errors, internet processing and packet sequencing, routing and passing.

Addressing and routing to ensure that the required level of the mains layer is the Lita of Service (QOS). ResidentIP algorithms and direction, protocols and ARP protocol) here. The data is transported across digital networks via routers and switches that use protocols to encapson them into a packet and algorithms that identify the best transmission path. This is known as switching packets.

3 layer 3 or network layer, switching takes place when the packet arrives on one router interface and is handed over to another. The protocols that may be present in the network layer include DDP (DDP), ICMP (ICMP), Internet Group Message Protocol (IGMP) and IGMP security) and IGMP security) and Internet protocol security). Among the commonly used protocols that include route information across network information (RIP), open the shortest path (OSPF), internal gateway routing protocol (IGRP), Border Gateway Protocol (BGP) and DVMRP protocol) and DIstant vector vector.

For information routing over the Internet, IP addresses are included in the header of the network layer messages, providing routers information that they need to decide how to manage data packets. The target address of the IP packet is checked when it is accepted at the router interface. If the router is not the goal of the packet, the router searches the network address in its routing table. The exit interface and the packet is selected to the interface to be framed and passed through the local network. The router drops the packet unless the target network item is found in the routing table.