Networking Devices

• Repeaters
• Hubs
• Bridge
• Switches
• Router
• Gateway

Repeater

 —  A repeater regenerates the signal it receives. In other terms, you can think of repeater as a device which receives a signal and retransmits it at a higher level or higher power so that the signal can cover longer distances.

—  No Filtering

—   Operates at the Physical Layer of OSI

Attenuation

Attenuation is a natural consequence of signal transmission over long distances.

Collision:

In a half duplex Ethernet network, a collision is the result of two devices on the same Ethernet network attempting to transmit data at exactly the same time. The network detects the "collision" of the two transmitted packets and discards them both.

Hubs

—   A hub is basically a multiport repeater. A hub connects multiple wires coming from different branches.

—  Hubs cannot filter data, so data packets are sent to all connected devices. It Depends on receiving computer that the packet is useful or not.

—  Shared Traffic

—  No addressing

—  Mostly used in LAN for Star topology

—  Operates at the Physical Layer of OSI

Bridge

—  Used for interconnecting two LANs working on the same protocol.. It has a single input and single output port, thus making it a 2 port device.

—  It can remove collision domain.

—  As compared Switches it use Software so it is slower then Switch and only 2 ports available so broadcasting not possible.

—  Functionality of filtering content by reading the MAC addresses of source and destination.

—  Data Transmission as Frame therefore, it operates at the Data Link Layer of OSI

Switch

—  Switch is more intelligent than a hub. While hub just does the work of data forwarding, a switch does ‘filter and forwarding’ which is a more intelligent way of dealing with the data packets.

—  It maintains a CAM (Content Addressable Memory) table that reads frame’s MAC destination address and forward to the destination. (If destination available)

—  It is faster than bridge because it has built in hardware chips for switching.

—  Reduces the Traffic just because multiport.

—  Data Transmission as Frame therefore, it operates at the Data Link Layer of OSI.

Router

—  A router is a network device which is responsible for routing traffic from one to another network. 

—  Connects deferent network LAN and WAN (eg. Internet)

—  Work with different protocols as well.

—  Router uses IP Address to forward packets.

—  Collision can be controlled by Router.

—  It creates Route Table using IP add and filter, forward packets to destination with best path.

Gateway

—  Gateway is very intelligent device from Router and it is combination of H/W and S/W.

—  It can operate with Network Layer and all above layers but mostly it operates with Application Layer of OSI.

—  It is very complex then Router.

—  It can handle different type of Protocols and network architecture.(it can connect and Translate)

  

 Conclusion:  

Repeater	Regenerate the signals
Hub	Forward all data to all ports
Bridge	Only 2 port (incoming and outgoing)
Switch	Frames forwarded to destination Unit-Frames (Data Link)
Router	Work with different  protocols (eg. Internet ) and provide routing facility.
Gateway	Handle different Protocols and Architecture . H/w and S/w