What is Hub in Computer Networks?
Hub is a networking device that operates on the physical layer i.e. the 1st layer of the OSI model, unlike switches that operate in data link layer. Hub connect multiple devices to itself that send and receive data through it. It is a multiport repeater that comes with add-on functionalities, such as indicating any issues with the device. They come in different variants such as 4, 8, and 16 port hubs.
Hub is a device that works as a central connection among all network equipment and handles a data type called frames. It is connected to multiple devices that allow forwarding. Any data coming from one of the connected devices in the hub can be forwarded to another connected device.
How Does a Hub Work?
A hub is a network device that consists of multiple ports. Each port can connect one device. Multiple devices get connected to the hub through these ports. A connected device, say 1, sends the frame (sender). This frame will be delivered to all the connected devices (receivers), say 2,3, and 4 in this case.
Suppose devices 1 and 2 simultaneously send frames/frames to the hub. Due to this, frames often crash. N number of collision domains are possible in the hub, where N refers to the number of devices connected to the hub. Whenever this collision occurs, the host that has sent the frame will detect it. The sent frames are destroyed, and the host sends a jam signal for other hosts to wait. The waiting period is different for each host to avoid any further collision.
Although the frame is sent to all ports, a connected device only accepts those frames or frames whose MAC matches the destination MAC address field. The rest of the frames are discarded by that device.
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Types of Hubs in Computer Networks
Let us now discuss the three types of network hubs in computer networks.
Advantages of Hub in Computer Networks
Here are some of the advantages of Hub:
- Message broadcast: A host in a hub sends messages to every other device in the connecting network.
- Cheaper devices: Among routers, hubs and switches; hubs are the least expensive since they are purely hardware.
- Easy installation: It can be easily installed thus it automatically creates a local area network (LAN). Any further addition in devices is possible later on as well.
- Easy removal of damaged device: Due to the different connecting wires, the hub remains perfectly functional even if one of the network segments stops working. Suppose that the wire of connected device 1 gets damaged, the hub will still be able to send messages to the remaining connected devices 2, 3 and 4.
Limitation of Hub in Computer Networks
Here are some of the disadvantages of Hub:
- Not intelligent: Unlike switch or router, hub is a less intelligent device since it does not have any software.
- Hub is everything: Total damage to the hub will cause the entire network to fail, even if all ports are perfectly functional.
- No filtering: Hubs do not allow packet filtering. This means that any data that is being forwarded to one device will also be forwarded to all connected devices. It, however, does not forward the frame to the port of entry. Since the hub is purely hardware, it does not have a MAC address for locating the target device.
- No security: Since the hub broadcasts messages to every port, it is not possible to send any private frame. This allows other connected ports to access your data.
- Network Traffic is high: Hubs broadcast the frame/data to every connected device due to which the traffic is high.
- Does not use full duplex transmission mode: Hubs use the half-duplex method for transmission. In the half duplex mode, you can either send a frame or receive a frame at a time. It is not possible to send and receive frames simultaneously.
- Cannot connect to different network architectures: Hubs cannot connect with different network architectures such as token, ring, and ethernet.
Difference Between Hub and Switch
Here are the differences between a hub and a switch in a tabular format:
| Benchmark |
Hub |
Switch |
| Definition |
A networking device that connects multiple devices and broadcasts data to all ports. |
A networking device that connects multiple devices and forwards data intelligently to specific ports. |
| Functionality |
Works at the physical layer (Layer 1) of the OSI model. |
Operates at the data link layer (Layer 2) or network layer (Layer 3). |
| Data Transmission |
Broadcasts data to all connected devices, regardless of the recipient. |
Sends data only to the intended device using MAC or IP addresses. |
| Efficiency |
Less efficient as it creates unnecessary network traffic. |
More efficient by reducing unnecessary traffic through intelligent forwarding. |
| Speed |
Typically limited to 10 Mbps or 100 Mbps. |
Supports higher speeds, ranging from 10 Mbps to 1 Gbps and beyond. |
| Collision Domain |
All devices share the same collision domain, leading to more collisions. |
Each port has its own collision domain, reducing collisions. |
| Bandwidth Utilization |
Shared bandwidth among all ports, leading to slower performance. |
Dedicated bandwidth per port for better performance. |
| MAC Address Table |
Does not maintain a MAC address table. |
Maintains a MAC address table to store device information. |
| Security |
Less secure as data is broadcast to all devices. |
More secure as data is sent only to the intended recipient. |
| Cost |
Cheaper compared to a switch. |
More expensive than a hub. |
| Use Case |
Suitable for small, simple networks with limited devices. |
Ideal for larger, more complex networks with many devices. |
| Examples |
Connecting a few computers in a home or small office. |
Used in modern office networks, data centers, and enterprise environments. |
If you want to learn in detail how a hub differs from a switch in networking, read the Difference Between Hub and Switch article. It will surely help!
Difference Between Hub and Router
For a better understanding, let's explore the differences between a hub and a router in a tabular format.
| Benchmark |
Hub |
Router |
| Definition |
A device that connects multiple devices in a network and forwards data to all devices. |
A device that connects multiple networks and directs data between them. |
| Functionality |
Broadcasts data to all connected devices. |
Routes data to a specific device or network. |
| Layer of Operation |
Works at the Physical Layer (Layer 1) of OSI. |
Works at the Network Layer (Layer 3) of OSI. |
| Data Transfer Mode |
Half-duplex (one-way at a time). |
Full-duplex (simultaneous two-way). |
| Intelligence |
Does not analyze or process data. |
Processes and analyzes data packets for routing. |
| Efficiency |
Low efficiency due to unnecessary broadcasting. |
High efficiency due to targeted data delivery. |
| IP Addressing |
Does not use IP addresses. |
Uses IP addresses for routing decisions. |
| Network Type |
Suitable for small, simple networks. |
Suitable for complex networks like LAN/WAN. |
| Security |
No security features. |
Provides security through firewalls and filters. |
| Price |
Generally inexpensive. |
Relatively more expensive. |
Hubs are basic networking devices that operate at the physical layer of the OSI model, simply broadcasting data packets to all connected devices. In contrast, switches operate at the data link layer and can intelligently direct data packets to specific devices based on MAC addresses, significantly enhancing network efficiency. On the other hand, routers function at the network layer and manage traffic between different networks to determine the best paths for data transmission.
Conclusion
I hope this article has answered the query about what a hub is, its types, and how it works. Hub is a device that is less intelligent and yet quite useful. They, however, lack the intelligence that other advanced hardware devices have. Therefore, they are now less in use and are being replaced by more intelligent devices such as switches and routers.
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FAQs
Is hub a router?
No, while both are networking devices the two operate at different layers. Hub operates at the physical layer which is the 1st layer of the OSI model and the router operates at the network layer which is layer 3.
What is the difference between a hub and switch?
Hubs and switches serve similar functions in networking by connecting multiple devices, but they operate differently. Hubs broadcast data packets to all connected devices, meaning each device receives the same data, which can cause congestion. In contrast, switches intelligently forward data only to the intended recipient based on MAC addresses, reducing collisions and improving network efficiency. For more information read the Difference Between Hub and Switch article.
Are hubs still used?
Hubs lack software, due to which they have limitations. They lack privacy and security. Due to these reasons, they are being replaced by network switches.
Do hubs have any advantages over switches?
Hubs are typically simpler and less expensive than switches, but their advantages are outweighed by their inefficiency in handling network traffic compared to switches.
How can I identify a hub in a network setup?
Hubs are often smaller, have multiple Ethernet ports, and lack configuration or management options compared to switches.
What is difference between hub and gateway?
Here are the differences between hub and gateway:
| Aspect |
Hub |
Gateway |
| Definition |
A networking device that connects multiple devices in a LAN and broadcasts data to all connected devices. |
A networking device that connects two different networks with different protocols or architectures. |
| Functionality |
Broadcasts data to all connected devices without filtering or routing. |
Translates and forwards data between networks with different communication protocols. |
| Layer in OSI Model |
Operates at the Physical Layer (Layer 1). |
Operates at multiple layers, often at the Application Layer (Layer 7) or Network Layer (Layer 3). |
| Data Processing |
Does not process or filter data; simply forwards it. |
Processes and converts data to make it compatible between networks. |
| Use Case |
Used within a local network to connect devices like computers and printers. |
Used to connect networks such as a LAN to the Internet or a private network to a public one. |
| Intelligence |
Non-intelligent device; does not perform data routing or management. |
Intelligent device capable of managing data and ensuring compatibility between networks. |
| Example |
Connecting computers in a LAN in a star topology. |
Connecting a home network to the Internet using a modem/router (gateway). |
| Efficiency |
Less efficient as it broadcasts data to all devices, leading to potential collisions. |
More efficient as it directs data only to the appropriate network or device. |
What is a Hub?
A hub is a device commonly used in a star topology that connects multiple cables from various devices. It cannot filter data, which means that any data it receives is sent to all connected devices. This creates a single collision domain for all the devices connected to the hub, meaning that they can all interfere with each other if they try to send data simultaneously.
What is the primary function of a hub in a computer network?
The primary function of a hub in a computer network is to connect multiple devices, such as computers and printers, within the same network segment. It acts as a central point for data transmission, receiving data packets from one device and broadcasting them to all other connected devices. This helps facilitate communication among the devices on the network.
What are the advantages and disadvantages of using hubs?
Here are the advantages and disadvantages of using hubs:
Advantages of Using Hubs
- Cost-Effective: Hubs are generally cheaper than more sophisticated networking devices like switches and routers, making them accessible for small networks or budget-conscious setups.
- Easy to Install: Hubs are simple to set up and require minimal configuration, which makes them user-friendly, especially for those with limited technical knowledge.
- Supports Multiple Connections: Hubs allow multiple devices to connect and communicate within the same network segment, facilitating easy data sharing among users.
Disadvantages of Using Hubs
- Network Collisions: Since a hub broadcasts data to all connected devices, it can lead to data collisions, which slow down network performance and efficiency.
- Limited Bandwidth: Hubs share bandwidth among all connected devices, which can result in lower network speeds as more devices join the network.
- No Intelligent Traffic Management: Hubs lack the filtering and traffic management capabilities found in switches, making them less efficient in directing data where it needs to go.
In what scenarios are hubs still used in modern networking?
Hubs are still used in modern networking in specific scenarios, such as small networks where simplicity and cost-effectiveness are prioritized. They may be employed in educational settings to teach basic networking concepts or in temporary setups where advanced functionalities are not required. Apart from all this, hubs can also be used for basic home networking, though they are gradually being replaced by more efficient switches.
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