Learn about routers, switches, and network hardware

Today we're taking a look at home network hardware: what the various pieces do, when you need them, and how to best deploy them. Keep reading to get a clearer picture of what you need to optimize your home network.

When do you need a switch? A hub? What exactly does a router do? Do you need a router if you only have one computer? Network technology can be a pretty obscure area of ​​study, but with the right terminology and a general overview of how devices operate on a home network, you can deploy your network with confidence.

Understand your home network with a network diagram

Rather than start with a glossary of network terms, assaulting you with technical jargon with no easy reference points in the process, let's go straight to a network diagram. This is the simplest network configuration available: a computer connected directly to a modem, which in turn is connected to an individual's Internet service provider via a phone line/cable/fiber uplink.

It doesn't get much simpler than this arrangement, but this ultra-simple setup comes at a price. This user cannot access the internet using a Wi-Fi device (so they can't use their smartphone, tablet, or other wireless device), and they lose the benefits of using a router between their computer and the greater internet. Let's introduce routers and highlight the benefits of using one. In the figure below, we've introduced two elements to the network: a wireless router and a laptop connected to the network via a wireless connection.

When should you use a router? Given the low cost of home routers and the benefits of having one on your network, you should always use a router (which almost always includes firewall functionality).

A home router is actually a combination of three network components: a router, a firewall, and a switch. In a business environment, these three pieces of hardware are separate, but consumer routers are almost always a combination of routing and switching components, with a firewall added in for good measure. First let's look at what a router does.

At the most basic level, a router connects two networks together, one inside your home (regardless of size) and the other outside your home (in this case, the Internet). The broadband modem that your ISP provides you with is only good for connecting a single computer to the Internet and typically does not include any routing or switching capabilities. Routers perform the following functions:

• IP Sharing: Your ISP assigns you an IP address. If you have a desktop, a laptop, a TV media box, and an iPad, one IP address is obviously not enough. The router manages these multiple connections and makes sure the right packets of information get to the right place. Without this feature, the person on the desktop and the person on the laptop wouldn't be able to browse the web at the same time because there would be no way to tell which computer was requesting what.
• Network Address Translation (NAT): Related to the IP sharing function, NAT modifies the headers in packets of information going in and out of the network so that they are routed to the correct device. Think of NAT as a very helpful receptionist in your router that knows exactly where every incoming/outgoing packet should go and tags them with the department accordingly.
• Dynamic Host Configuration: Without DHCP, you would have to manually configure and add all hosts to your network. This means that every time a new computer comes onto the network, you have to manually assign it a network address. DHCP does this for you automatically, so when you plug your XBOX into your router, your friend joins your wireless network, or you add a new computer, an address is assigned without manual intervention.
• Firewall: Routers act as basic firewalls in a number of ways, including automatically rejecting incoming data that isn't part of an ongoing exchange between computers within your network and the outside world. For example, if you request a music stream from Pandora, your router says, "We're waiting for you, come on in," and the data stream is directed to the device making the request. On the other hand, if a sudden burst of port probes comes from an unknown address, your router acts like a bouncer, rejecting the request, effectively disguising your computer. Even for a user with just one computer, a simple $50 router is worth it just for the firewall functionality.

In addition to the internal-to-external networking functions outlined above, a home router also acts as a network switch. A network switch is a piece of hardware that facilitates communication between computers on an internal network. Without switching capabilities, devices can communicate with the greater Internet through the router, but not with each other—something as simple as copying an MP3 from a laptop to a desktop over the network would be impossible.

Most routers have four Ethernet ports, allowing you to plug in four devices and have them communicate through the switch functionality. If you need more than four Ethernet connections, you'll need to upgrade to a router with a larger port bank (a fairly expensive proposition that will usually only give you up to eight ports), or you can opt for a dedicated switch.

Note: You only need to upgrade if you run out of physical ports for hardwired connections. If you only have one computer and one networked printer plugged into your four-port router (and everything else on the network is Wi-Fi based), you don't need to upgrade to gain physical ports. That said, let's look at a network with a dedicated switch.

While the four-port limit of most home routers is more than adequate for most home users, the number of networkable devices in a home has increased significantly over the past 10 years. It's not uncommon to have multiple computers, multiple game consoles, media centers, printers, file servers, and more all connected to your Ethernet LAN (while you might put a Wii on your Wi-Fi network for dedicated video streaming and media server access, for example, it's best to have a hardwired connection). Once you reach device saturation, you'll need to add a switch with eight, 16, or more ports to properly support your growing home network.

As an aside, historically people have often relied on hubs because they are much cheaper than expensive switches. A hub is a simple network device that does not inspect or manage any traffic passing through it - it is a "dumb" network device - in contrast, a switch actually interacts with packets and actively directs them. Since hubs have no management component, packets often collide with each other, resulting in poor overall performance. Hubs have many technical disadvantages, which you can read about here.

Over the past 10 years, the price of consumer-grade network switches has dropped dramatically, to the point where few hubs are produced (one of the largest consumer-grade hub manufacturers, Netgear, doesn't even make hubs anymore). Due to the shortcomings of network hubs and the low prices of high-quality consumer-grade network switches, we don't recommend using hubs. When you can buy a very good, high-speed 8-port switch for $25, there's no reason to use outdated hubs on your home network - if you're curious why network administrators deploy hubs, you can read about it here.

Back to the topic of switches: switches are an excellent, inexpensive way to increase the size of your home network. If the 4 ports on the back of your router exceed your capacity, the simplest thing you can do is to purchase a switch with the appropriate number of ports to expand your network. Unplug the devices from the router, plug all the devices into the switch, and then plug the switch into the router.

Note: Switches have absolutely no routing capabilities and cannot replace your router. Your router most likely has a four-port switch built into it, but that doesn't mean your new eight-port dedicated switch can replace your router -- you still need the router to coordinate between the modem and the switch.

Decoding network speed signs

Now that you have a clear idea of ​​how your network should be physically configured, let's talk about network speed. There are two main names that we are interested in: Ethernet and Wi-Fi. Let's look at Ethernet first.

Ethernet connection speeds are measured in 10BASE. The original Ethernet protocol, now 30 years old, had a maximum speed of 10 Mbit/s. Fast Ethernet, introduced in 1995, increased speeds to 100 Mbit/s. Gigabit Ethernet was introduced in 1998, but has only recently gained much traction in the consumer market. As the name suggests, Gigabit Ethernet is capable of 1000 Mbit/s. You'll often see these designations, like 10/100 or 10/100/1000, on networking gear and its packaging, indicating which version of Ethernet the equipment is compatible with.

To take advantage of the maximum speed, all devices in the transmission chain need to meet or exceed the rated speed you want. For example, let's say you have a media server with a Gigabit Ethernet card installed in the basement and a media console with a Gigabit Ethernet card installed in the living room, but you use a 10/100 switch to connect the two devices together. Both devices will be limited by the 100 Mbit/s cap on the switch. In this case, upgrading the switch will greatly improve your network performance.

Outside of transferring large files and streaming HD video content over your home network, there's little need to go out and upgrade all your devices to Gigabit. If your primary computer network use consists of web browsing and light file transfers 10/100 is more than satisfactory.

Understanding Wi-Fi Speed

Wi-Fi speeds are expressed with letters instead of numbers. Unlike the simple method of converting numbers to network speeds that we find in Ethernet, the Wi-Fi name actually refers to a draft version of the IEEE 802.11 networking standard that specifies the parameters of the Wi-Fi protocol.

• 802.11b was the first version to be widely adopted by consumers. 802.11b devices have a maximum transmission speed of 11 Mbit/s, but speeds vary greatly depending on signal strength and quality - realistically users should expect 1-5 Mbit/s. Devices using 802.11b will experience interference from baby monitors, Bluetooth devices, cordless phones, and other devices in the 2.4GHz band.
• 802.11g was the next major consumer upgrade, increasing maximum transfer speeds to 54 Mbit/s (actually about 22 Mbit/s, taking error correction and signal strength into account). 802.11g suffers from the same 2.4GHz band interference as 802.11b.
• 802.11n is a major upgrade to the Wi-Fi standard - devices use multiple-input multiple-output antennas (MIMO) to operate in the 2.4GHz and relatively unused 5GHz bands. 802.11n has a theoretical maximum of 300 Mbit/s, but taking into account error correction and less-than-ideal conditions, you can expect speeds in the 100-150 Mbit/s range.
• 802.11ac is a huge upgrade, bringing wider channels (80 or 160 MHz vs. 40 MHz), more spatial streams (up to 8), and things like beamforming, which sends waves directly to your device instead of bouncing around, making things a lot faster. How much faster? There are models that can handle 1 GB per second. It's really fast.

As with Ethernet, Wi-Fi speeds are limited by the weakest link in the direct network. If you have an 802.11n-capable Wi-Fi router, but your netbook only has an 802.11g-capable Wi-Fi module, you'll top out at 802.11g speeds.

Besides the speed limitations, there's a very pressing reason to move away from the oldest popular Wi-Fi protocol, 802.11b. You must use the same level of encryption on every device in your network, and the encryption schemes available to 802.11b devices are weak and have been broken (for example, WEP encryption can be broken in a matter of minutes by a tech-savvy kid) Upgrading your Wi-Fi router and wireless devices will allow you to upgrade your wireless encryption and enjoy faster speeds.

As with Ethernet, upgrading to the highest speeds (in this case, 802.11n) is best suited for people moving large files and streaming high-definition video. Upgrading to 802.11n will have a negligible impact on your web browsing speeds, but will have a huge impact on your ability to wirelessly stream high-definition content throughout your home.

Now that you have a handle on how your home network is laid out, and you understand what network speeds mean and how they can affect you and your network, it’s time to upgrade your switches, roll out some new Wi-Fi bandwidth, and enjoy a more optimized home network.