Routers, Switches, and Hubs
By Erik Rodriguez
This article is all about routers, switches, and hubs. It explains what they do, how they different from each other, and why you would use one over the other.
Before the year 2000, the majority of the public had no idea what any of these devices were. Since the introduction of broadband Internet connections, these devices have gained popularity. Just about everyone knows what a router is now. Or as some people like to pronouce them "rooters." While they all perform different tasks, each device plays an important role in networking. In the duration of this article, I will discuss each device individually. Then, I will discuss any similarities and differences between each device.
The network hub has been around for ages. These devices are sometimes referred to as repeaters. A hub sees information in the form of bits. Using a hub is now the cheapest way to connect devices. Hubs work by broadcasting network traffic across all ports. For example, an 8 port hub will broadcast data across all 8 ports even though the data is meant to travel between two devices. For this reason, hubs incur an increased amount of collisions. A collision is simply the results of two devices (computers) trying to broadcast simultaneously. Collisions are a normal part of network traffic. Ethernet itself is a collision based technology. The image below shows a simple network hub.
Switches have become more complex with increased popularity of high-speed networks. They can range in price for around $30 to well in the $1000s. However, in recent years the prices of switches has dramatically decreased. Switches perform the same functionality of hubs, except they only send data to intended ports. Unlike a hub, a switch will not broadcast data across the entire switch. As a result, switches will not suffer from a high rate of collisions. High-end switches offer advanced functionality such as VLAN management. Complex networks will use several layers of switches of pass along large amounts of network traffic. The image below shows a simple network switch. Notice that it is similar in appearance to the hub above. Physically, the switch is a little taller and deeper. These switches usually contain 1 or more cooling fans and can be quite loud.
Routers are the smartest of the 3 devices. They make intelligent decisions on how to route traffic. Routing protocols are composed of different algorithms that direct the way routers move traffic. These devices can range from around $30 to well in the $1,000,000s. The Internet itself uses complex routers fed by fiber optics to connect cities and countries together. Routers play the most important role in operating a network. They are the most dynamic of all 3 devices mentioned in this article. They can work with or act as firewalls. The image below shows a low-end Cisco router:
Switch vs. Hub
Think of it like this, a hub is like getting spam. You have an address, but the spammers don't know you personally, they just know you exist and send you mail regardless. On the other hand, legit mail is sent by someone that intends to send you an important piece of information. Think of the post office as a switch. All the mail is sent through them. They sort it based on name and address, then it's delivered. Make Sense?