1. Networking Components
A detailed look at a Hub, switch, router, bridge, gateway, firewall and wireless AP.
By Daniel Baxter

2. The Hub
A hub connects computers without any real understand about what it is transferring. When a hub gets data it broadcasts the data to all devices connected to it regardless of destination.
In the past switches and routers were expensive so people used hubs. Now that prices have dropped hubs are rarely used.
Cost: It was hard to find any hubs since they have been replaced by switches, but the above Dlink hub ran dollars. Most hubs range from 10 to 40 dollars.
In the above diagram we see a hub transporting its information in between a laptop and two desktop computers. If the laptop sends something it broadcasts it to all the devices not any specific one. Again there is no determination of the destination of the data since a hub does not process layer 2 or 3 traffic. It works simply on Layer 1 of the OSI model.

3. The Switch
The main difference between a hub and a switch is that a switch can operate on the Layer 2 of the OSI model. They are essentially intelligent hubs. They are intelligent because they build address table in hardware to keep track of different hardware addresses and the port to which each hardware address is associated.
Usually large networks use switches instead of hubs to connect computers within the same subnet.
Cost: This Dlink switch costs on Amazon. Switches vary in pricing. Some are inexpensive like this one other more complicated ones can be over 100 dollars.
Above we see a switch moving data around. Now the difference with the switch is that it can send data on layer 2 of OSI model. So if the laptop wants to send data to the desktop closest to it, the switch can determine that and will send it to the correct address.

4. The Router
Routers can work on level 3 of OSI model. Routers can forward data across networks. Sometimes they are called level 3 switches because of this. Usually, routers use the IP address to forward packets, which allows the network to go across different protocols.
Routers are used in most home networks to connect them with the internet.
Cost: This particular Netgear Nighthawk router costs 190 dollars on Amazon. It is also a wireless access point as well which makes it more expensive. Routers range from 30 dollars to over 200 dollars.
In the above diagram we see a router routing traffic from the internet to three different devices. Since it can operate at level 3 of the OSI model it can receive information from other computers outside the network and sent that information via IP address to Desktop 1 for example.

5. The Bridge
People with a small network usually use a bridge when they want to exchange information or share files among all of the computers on those networks. Bridges essentially connect one LAN to another LAN. They work at OSI level 2. They forward data using MAC addresses across networks.
Usually people who are on the same subnet connect two LANs with a bridge. This usually is a small or home network.
The above Lincsys wireless bridge costs 64 dollars new on Amazon. Most range from 30 to over 100 dollars.
In the above diagram you can see a bridge is connecting to local area networks or LANs. In LAN1 is inhabited by Desktops 1 and 2 as well as a laptop. LAN 2 is inhabited by Desktops 3 and 4. If Desktop 4 wanted to send a packet to Desktop 1 it would send it through the bridge using a MAC address. The bridge would read the MAC address and forward the data to Desktop 2.

6. The Gateway
The main difference between a gateway and a router is that the gateway can connect to different types of networks. It is essentially a portal to connect to different networks usually through the internet. It operates primarily on layer 3 of the OSI model.
A gateway is used by large networks to make their network assessable to other networks that may not be using the same protocols.
Cost: Gateways are fairly expensive. The Verison Fios gateway costs 179 dollars on Amazon, but retails for over 229 dollars. The gateways I found were expensive, usually from 100 to 300 dollars.
In this diagram you see a gateway is connecting two networks. One network is a Windows NT Network which uses TCP/IP as its primary protocol. The other network is a Netware network which uses a different protocol. The gateway can regulate traffic in between these two networks.

7. The firewall
A firewall is a software program or a piece of hardware that protects your computer network form outside threats. It is designed to block outside access that is unauthorized.
All messages that inter the network are examined by the firewall according to a specific security criteria. If the data does not meet that criteria it is blocked.
Most home networks do not use hardware firewalls unless a router is designed to act as one. Most home computers use software firewalls. Hardware firewalls are more effective, but difficult to upgrade and change.
The above Zyxell hardware firewall is currently on Amazon for 150 dollars, but some firewalls can reach as high as 500 dollars.
In this diagram above you see a firewall protecting a small computer network. I am going to say that it is a hardware firewall that is integrated into the router. If a packet of data tries to enter the network the firewall examines it. If it is ok, it is let through. If not, it is blocked by the firewall.

8. The Wireless Access Point
Although the assumption most people make is that a router is always a wireless access point (WAP). That is not technically true. Some routers do not have wireless capability. A wireless access point is a device that can send wireless radio waves out and connect compatible computers in that fashion. Most of the time a WAP is a router however.
A WAP that is connected with a router will receive a connection request from a computer and it will connect that computer wirelessly with the WAP. Once a connection is established the computer can use the WAP to send packets and receive packets via radio waves wirelessly.
WAP’s that are connected with routers can be as high as 199 dollars as in the case of this Netgear Nighthawk. However some basic WAPs are as low as 20 dollars.
In the diagram above the WAP is integrated into a Netgear Nighthawk router. The router is connected to the desktops and the laptop via CAT5 cable. However it is also a WAP and is connected to the iPhone and the iPad via wireless radio waves.

10. references
Computer Hope writer(2015). Difference between a network hub, switch, and router? Retrieved from
Arora, H. (2013, September 5). Hubs vs Switches vs Routers – Networking Device Fundamentals. Retrieved from
Posey, B. (2000, July 9). Understanding the differences between gateways and routers. Retrieved from
RouterSwitch.com writer (2013, September 26). Tutorial of the differences between a Hub, Bridge, Switch and Router. Retrieved from and-router.html
Maufer, T. A. (n.a). Router? Bridge? Switch? Hub? What's the difference? Retrieved from