Data Link Layer Provide Physical Addresses
The second layer in the OSI Reference model is the Data Link Layer. The data link layer is responsible for providing physical addresses for the devices connected to the network. The physical address is also called hardware address because it is built-in address (not a logical address like IP address). The data link layer is responsible for taking bits from the Physical layer and convert them to frames. All communications done in Data link layer is in the form of frames.
In IEEE version of Ethernet, Data link layer is subdivided in to:
1. Logical Link Control (LLC)
2. Media Access Control (MAC)
Data-link Layer devices
Networking devices functioning at Data link layer are:
Responsibilities of Data Link Layer
The seven layer structure of the OSI Reference Model is listed below.
Sub division in Data-link Layer
In IEEE version of Ethernet, Data link layer is subdivided in to:
1. Logical Link Control (LLC)
2. Media Access Control (MAC)
Data-link Layer devices
Networking devices functioning at Data link layer are:
- Switch
- NIC
- Bridge
Responsibilities of Data Link Layer
- Define Physical Addresses
- Communication in the same network in form of Frames
- Define hardware topology of the network
Major Data Link layer Protocols
- CIF : Cells in Frames Ethernet
- FDDI : Fiber Distributed Data Interface
- GARP : Generic Attribute Registration Protocol
- GMRP : Multicast Registration Protocol.
- GVRP :GARP VLAN Registration Protocol
- LLC :Logical Link Control.
- SNAP :SubNetwork Access Protocol
Seven Layer Structure
The seven layer structure of the OSI Reference Model is listed below.
- Physical layer
- Data link layer
- Network layer
- Transport layer
- Session layer
- Presentation layer
- Application layer