Data Link Layer Provide Physical Addresses

The second layer in OSI Reference model is Data Link Layer. Data link layer is responsible for providing physical addresses for the devices connected to the network. Physical address is also called hardware address because it is built in address (not a logical address like IP address). Data link layer is responsible for taking bits from Physical layer and convert them to frames. All communications done in Data link layer is in the form of frames.


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:

  1. Switch
  2. NIC
  3. Bridge

Responsibilities of Data Link Layer
  1. Define Physical Addresses
  2. Communication in the same network in form of Frames
  3. Define hardware topology of the network

Major Data Link layer Protocols

  1. CIF : Cells in Frames Ethernet
  2. FDDI : Fiber Distributed Data Interface
  3. GARP : Generic Attribute Registration Protocol
  4. GMRP : Multicast Registration Protocol.
  5. GVRP :GARP VLAN Registration Protocol
  6. LLC :Logical Link Control.
  7. SNAP :SubNetwork Access Protocol

Seven Layer Structure

The seven layer structure of OSI Reference Model is listed below.
  1. Physical layer

  2. Data link layer

  3. Network layer

  4. Transport layer

  5. Session layer

  6. Presentation layer

  7. Application layer

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1 comment:

Extreem said...

In data link layer data is in the format of frames.