OSI Layers In OSI Model: Simple Guide In 10 Points
Introduction
The OSI Model is a conceptual and logical model that characterizes network communication utilized by systems open to communication and interconnection with different systems. We will below understand various OSI layers and its functions.
The Open System Interconnection or OSI reference model also characterizes a logical network and adequately depicts the computer packet transfer by utilizing different protocols.
The recent Internet did not depend on Open System Interconnection, yet the less difficult TCP/IP model. Notwithstanding, the seven OSI layers model is still broadly utilized, as it envisions and imparts how networks work and help isolate and troubleshoot networking issues.
List of OSI layers
The list of OSI layers in tabular format is under:
- OSI Architecture
Layer | Name of Layer | ||
Layer 7 | Application | Software/Upper Layers |
Sender ↓ Receiver ↑ |
Layer 6 | Presentation | ||
Layer 5 | Session | ||
Layer 4 | Transport | Heart of OSI | |
Layer 3 | Network | Hardware/Lower Layers |
|
Layer 2 | Data-Link | ||
Layer 1 | Physical |
OSI layers and functions
- Physical Layer in the OSI Model
- Data-Link Layer in the OSI Model
- Network Layer in the OSI Model
- Transport Layer in the OSI Model
- Session Layer in the OSI Model
- Presentation Layer in the OSI Model
- Application Layer in the OSI Model
- OSI model with protocols
- OSI layers and devices
- OSI layers attacks
1. Physical Layer in the OSI Model
The physical layer encourages you to determine the physical and electrical determinations of the data connection.
Physical OSI Layer: Sending cable → Bitstream → Receiving Cable
Physical Layer Functions:
- It gives the synchronization of the bits by giving a clock.
- It isn’t worried about protocols or other such higher-layer things.
- It additionally determines the transmission rate.
2. Data-Link Layer in the OSI Model
The data link layer is very much like the network layer, aside from the data link layer encourages data to move between two devices on a similar network.
Data-Link OSI Layer: Frame Creation → Transport → Transfer Frames Between Network Nodes
Data-Link Layer Functions:
- It adds logical locations of the receivers and sender.
- It additionally offers a framework for mistake control wherein it recognizes retransmits harm or lost frames.
- Framing separates the data from the network layer into frames.
3. Network Layer in the OSI Model
It works for the transmission of data from one host to the next situated in various networks.
Network OSI Layer: Packets Creation → Transport → Packets Assembly
Network Layer Functions:
- Its protocols to figure out which route is reasonable from source to destination.
- It breaks portions from the transport layer into more modest units.
- The sender and receiver’s IP address are set in the header by the network layer.
4. Transport Layer in the OSI Model
It deals with the delivery and error checking of data packets.
Transport OSI Layer: Segmentation → Transport → Reassembly
Transport Layer Functions:
- It ensures that the message is conveyed to the correct interaction on the destination machine.
- It directs the sequencing, size, and eventually the transfer of data between hosts and systems.
- It additionally ensures that the whole message shows up with no mistake else. It ought to be retransmitted.
5. Session Layer in the OSI Model
This layer is answerable for the establishment of connection, support of sessions, verification and guarantees security.
Session OSI Layer: Session of Communication
Session Layer Functions:
- It additionally permits an interaction to add a checkpoint to the steam of data.
- It empowers two frameworks to go into a dialogue.
- It establishes, maintains, and closes a session.
6. Presentation Layer in the OSI Model
It permits you to determine the form in which the data is to trade between the two communicating entities.
Presentation OSI Layer: Encryption → Compression → Translation
Presentation Layer Functions:
- It causes you to encode data for security purposes.
- Diminishes the number of bits that should be transmitted to the network.
- It gives a UI and support for services like file and email transfer.
7. Application Layer in the OSI Model
The Application Layer (7 layers of OSI Model) is the lone layer that straightforwardly interacts with data from the client.
Application OSI Layer: Return Content in Required Format → ← Website
Request Content → ← Website
Application Layer Functions:
- This layer gives different email services.
- Network Virtual Terminal.
- It permits clients to log on to a distant host.
8. OSI model with protocols
Layer Name Protocols | Protocols |
Application Layer Protocol | SNMP, POP3, FTP, HTTP, SMTP |
Presentation Layer Protocol | TLS, SSL, ASCH, MPEG |
Session Layer Protocol | SAP, NetBIOS |
Transport Layer Protocol | UDP, TCP |
Network Layer Protocol | MPLS, ARP, IPSEC, ICMP, IPV6, IPV5 |
Data-Link Layer Protocol | Fibre Cable, ATM, Frame Relay, PPP, RAPA, and so on. |
Physical Layer Protocol | ISDN, 100BaseTX, RS232 |
9. OSI layers and devices
OSI Layer | Devices |
Application Layer | Application Proxy Firewalls |
Presentation Layer | N/A |
Session Layer | N/A |
Transport Layer | N/A |
Network Layer | Router, Layer 3 Switch |
Data-Link Layer | NICs, Bridges, Switches, Encryption Devices |
Physical Layer | Modems, Repeater, Hubs, NICs, Connectors, Cables |
10. OSI layers attacks
Layers | Attacks |
Application Layer | Version Rollback Attack, Send Mail, FTP, and Network File System Bugs |
Presentation Layer | |
Session Layer | Portmapper Exploits and Remote Procedure Call Worms |
Transport Layer | Sequence Number Prediction, SYN Flooding, and Routing Information Protocol Attacks |
Network Layer | IP Smurfing and Other Address Spoofing Attacks |
Data-Link Layer | Wired Equivalent Privacy Attacks |
Physical Layer |
Conclusion
The types of OSI layers are a conceptual and logical model that determines network communication which is utilized by frameworks open to communication and interconnection with different frameworks.
OSI layers causes you to comprehend communication over a network.
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