- Data Comm & Networks Home
- DCN - Overview
- DCN - What is Computer Network
- DCN - Uses of Computer Network
- DCN - Computer Network Types
- DCN - Network LAN Technologies
- DCN - Computer Network Models
- DCN - Computer Network Security
- DCN - Components
- DCN - Connectors
- DCN - Switches
- DCN - Repeaters
- DCN - Gateways
- DCN - Bridges
- DCN - Socket
- DCN - Network Interface Card
- DCN - NIC: Pros and Cons
- DCN - Network Hardware
- DCN - Network Port
- Computer Network Topologies
- DCN - Computer Network Topologies
- DCN - Point-to-point Topology
- DCN - Bus Topology
- DCN - Star Topology
- DCN - Ring Topology
- DCN - Mesh Topology
- DCN - Tree Topology
- DCN - Hybrid Topology
- Physical Layer
- DCN - Physical Layer Introduction
- DCN - Digital Transmission
- DCN - Analog Transmission
- DCN - Transmission media
- DCN - Wireless Transmission
- DCN - Transmission Impairments
- DCN - Multiplexing
- DCN - Network Switching
- Data Link Layer
- DCN - Data Link Layer Introduction
- DCN - Data Link Control & Protocols
- DCN - RMON
- DCN - Token Ring Network
- DCN - Hamming Code
- DCN - Byte Stuffing
- DCN - Channel Allocation
- DCN - MAC Address
- DCN - Cyclic Redundancy Checks
- DCN - Error Control
- DCN - Flow Control
- DCN - Framing
- DCN - Error Detection & Correction
- DCN - Error Correcting Codes
- DCN - Parity Bits
- Network Layer
- DCN - Network Layer Introduction
- DCN - Network Addressing
- DCN - Routing
- DCN - Internetworking
- DCN - Network Layer Protocols
- DCN - Routing Information Protocol
- DCN - Border Gateway Protocol
- DCN - OSPF Protocol
- DCN - Network Address Translation
- DCN - Network Address Translation Types
- Transport Layer
- DCN - Transport Layer Introduction
- DCN - Transmission Control Protocol
- DCN - User Datagram Protocol
- DCN - Congestion Control
- DCN - TCP Service Model
- DCN - TLS Handshake
- DCN - TCP Vs. UDP
- Application Layer
- DCN - Application Layer Introduction
- DCN - Client-Server Model
- DCN - Application Protocols
- DCN - Network Services
- DCN - Virtual Private Network
- DCN - Load Shedding
- DCN - Optimality Principle
- DCN - Service Primitives
- DCN - Services of Network Security
- DCN - Hypertext Transfer Protocol
- DCN - File Transfer Protocol
- DCN - Secure Socket Layer
- Network Protocols
- DCN - ALOHA Protocol
- DCN - Pure ALOHA Protocol
- DCN - Sliding Window Protocol
- DCN - Stop and Wait Protocol
- DCN - Link State Routing
- DCN - Link State Routing Protocol
- Network Algorithms
- DCN - Shortest Path Algorithm
- DCN - Routing Algorithm
- DCN - Leaky Bucket Algorithm
- Wireless Networks
- DCN - Wireless Networks
- DCN - Wireless LANs
- DCN - Wireless LAN & IEEE 802.11
- DCN - IEEE 802.11 Wireless LAN Standards
- DCN - IEEE 802.11 Networks
- Multiplexing
- DCN - Multiplexing & Its Types
- DCN - Time Division Multiplexing
- DCN - Synchronous TDM
- DCN - Asynchronous TDM
- DCN - Synchronous Vs. Asynchronous TDM
- DCN - Frequency Division Multiplexing
- DCN - TDM Vs. FDM
- DCN - Code Division Multiplexing
- DCN - Wavelength Division Multiplexing
- Miscellaneous
- DCN - Shortest Path Routing
- DCN - B-ISDN Reference Model
- DCN - Design Issues For Layers
- DCN - Selective-repeat ARQ
- DCN - Flooding
- DCN - E-Mail Format
- DCN - Cryptography
- DCN - Unicast, Broadcast, & Multicast
- DCN - Network Virtualization
- DCN - Flow Vs. Congestion Control
- DCN - Asynchronous Transfer Mode
- DCN - ATM Networks
- DCN - Synchronous Vs. Asynchronous Transmission
- DCN - Network Attacks
- DCN - WiMax
- DCN - Buffering
- DCN - Authentication
- DCN Useful Resources
- DCN - Quick Guide
- DCN - Useful Resources
Network Layer Introduction
What is Network Layer (Layer-3)?
Layer-3 in the OSI model is called Network layer. Network layer manages options pertaining to host and network addressing, managing sub-networks, and internetworking.
Network layer takes the responsibility for routing packets from source to destination within or outside a subnet. Two different subnet may have different addressing schemes or non-compatible addressing types. Same with protocols, two different subnet may be operating on different protocols which are not compatible with each other. Network layer has the responsibility to route the packets from source to destination, mapping different addressing schemes and protocols.
Network Layer (Layer-3) Functionalities
Devices which work on Network Layer mainly focus on routing. Routing may include various tasks aimed to achieve a single goal. These can be:
Addressing devices and networks.
Populating routing tables or static routes.
Queuing incoming and outgoing data and then forwarding them according to quality of service constraints set for those packets.
Internetworking between two different subnets.
Delivering packets to destination with best efforts.
Provides connection oriented and connection less mechanism.
Network Layer Features
With its standard functionalities, Layer 3 can provide various features as:
Quality of service management
Load balancing and link management
Security
Interrelation of different protocols and subnets with different schema.
Different logical network design over the physical network design.
L3 VPN and tunnels can be used to provide end to end dedicated connectivity.
Internet protocol is widely respected and deployed Network Layer protocol which helps to communicate end to end devices over the internet. It comes in two flavors. IPv4 which has ruled the world for decades but now is running out of address space. IPv6 is created to replace IPv4 and hopefully mitigates limitations of IPv4 too.