What Are Network Devices... and What Do They Do?
When you sit down to get something done on your computer, you may not realize it but you're relying on more than your Internet browser to get information, go shopping or send emails.
You're also relying on having an IP address that recognizes your computer, as well as a reliable network that you're connected to—and that can connect with everyone else. And that's what makes the "connectivity" possible.
Networks are more than computers and wiring. There also have to be specific devices—specialized pieces of hardware—that handle electrical/digital connections and perform their unique roles efficiently.
A little networking background.
Most networks are small—think of a small office or home—and even large networks are often divided into smaller segments. That smaller segment is set apart from the larger network by a device that can filter data and help the network be more efficient.
These devices that filter traffic are called connectivity devices, and there are several different types:
Here's what these connectivity devices, working together, are primarily responsible for:
- Controlling traffic. Large networks need a way to filter and isolate data traffic.
- Connectivity. These devices can connect different types of networks using different types of network protocols.
- Hierarchical addressing. Segmenting the network with connectivity devices provides an actual (physical) example of delivering actual data to the right destination through the IP address's network ID and host ID.
Here's a brief description of these different devices:
Definition: A connectivity device that forwards data based on a physical address.
In networking terms, a bridge filters and forwards packets by physical address. Bridges operate at the Network Access Layer in the TCP/IP protocol stack.
Definition: A connectivity device to which network cables are attached to form a network segment. Hubs typically do not filter data, but instead retransmit incoming data packets or frames to all parts.
Almost all networks today use a central hub or switch to which the computers on the network connect. In a hubbed network, each computer is connected to the hub through a single line. That makes adding a host to the network, or taking it off, a simple task.
Definition: A switch is aware of addresses associated with each of its ports and forwards each incoming data frame to the correct port. Switches can base forwarding decisions on guidelines that are provided in the headers of the TCP/IP protocols.
A switch, simplified, is a smarter version of a hub. On a switch, as with a hub, each computer is connected through a single line. However, the switch is smarter about where it sends data that comes in through one of its ports.
Defined: A connectivity device that filters and forwards data based on a logical address. In the case of TCP/IP networks, that would be the IP address.
Routers are an essential part of any larger TCP/IP network. In fact, without the development of network routers and TCP/IP routing protocols, the Internet (the biggest network in the world) would not have become as extensive. Routers play a vital role in controlling traffic and keeping the network efficient.
Seamless, incredible efficiency.
Working independently and working together, connectivity devices do a remarkable job of handling your specific Internet requests...simultaneously, with millions more being handled every second around the world.
So wherever you are and whatever computer you are using, you can rely on networking hardware to bring the world to your fingertips.