Computer Networking 101
Published By
Mike Sorrentino
Published On
June 2024
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Intro
According to a Forbes survey of business in 2023 only 8% of people use Cash.
So what is a computer network?
It starts with a modem which brings the internet into your location. The two most popular ways to get internet from an Internet Service Provider(ISP) are coaxial cable or Fiber optics. The ISP is responsible to wire up to this point and usually supply the modem. Next in line is the Router. The ISP can provide or it can be your own. Since this is for business, a business class router with a decent Firewall would be prudent. A Firewall is a security feature inside of the router that monitors and filters incoming and outgoing network traffic. The router is like the traffic cop of your network. Not only will it communicate with the modem to allow internet access. It looks for suspicious activity and allows two way communication between each and every device on your network. It's a full time job, a router is not a great place to skimp. The Internet coming in is usually termed the WAN or Wide Area Network. While from the router to the rest of the devices is termed LAN or Local Area Network. The LAN is the network that your router is creating. One very common misconception I see a lot, is people seeing a wifi connection and assuming they have an internet connection. If you are connected to a router via Wifi or ethernet it means you are connected to the LAN from that router. It means all the devices are talking to each other but it doesn’t necessarily mean you are connected to the internet. On the router while your POS system is all hooked up, if you remove the ethernet wire plugged into the WAN/Internet port on your router the whole POS system will still be able to communicate but you will not be able to run credit card payments since you will no longer be connected to the internet. You will be “offline” but you should still be able to take cash payment and print receipts without issue.
IP addressing
Once all the devices are connected to the router they should be able to communicate with each other. The caveat is all the devices have to be on the same network to allow communication. Routers use a unique IP address to ‘name’ specific devices so it knows which devices are which. On your LAN you can have a dynamic IP address that the router generates and assigns for you or you can set them yourself. I could caution you to use the dynamic IP’s from your router unless you know a bit about Networking. Without a good working knowledge of networks it can get very complicated very quickly. The IP addresses are also used to signal to the router which network each device is on. For example 192.168.2.2 would not be on the same network as 10.1.10.1. There is a lot more to it but for simplicity you want to match the first 3 sets of numbers. You can have a router that has an IP address of 192.168.2.2 and a printer with an IP address of 192.168.2.100. As you can see the first 3 sets of numbers match and the last set is what makes the device unique. Each node/device on the network should be unique.
Wifi vs Hardwired
There are two ways to communicate from the router to all the other devices on the network; Ethernet wires and Wifi. There are Pros and Cons to both approaches. Let's start with Wifi. Wifi gives you the ability to communicate over the network wirelessly via radio frequencies. The nice thing about wifi is the convenience. You don’t have to run ethernet wires everywhere you want a POS station or printer. You don’t have to worry about those lines getting damaged or destroyed. But the convenience does come with a cost. Radio waves through the air are not as reliable as a direct wired connection. Signals can drop or have a weak signal resulting in communication failures. Radio signals also have a tough time going through cement, glass and water. People are made up of mostly water so a full dining room could result in reduced signal strength. Sometimes this might not be a big deal, say if when the customer asks for a receipt it doesn’t print, you are right there and see it did not print and you can simply print it again. But think if you're a restaurant server and you put in food order and the kitchen printer is connected via wifi; you want to be 100% sure that order was received by the cooks!
On the other hand you can hardwire the connections. Hardwiring ethernet lines is the most reliable connection to each other device. There is a cost related to running wires too. First there is the actual running of the lines. Ethernet lines are not delicate but there are 8 thin copper lines wrapped together inside the sheathing. If those thin cables are damaged it could slow or stop the connection. Having a professional run the lines could mitigate unnecessary headaches. There are additional concerns with someone pulling too hard on a cable or an animal damaging the wires. But if your goal is speed and reliability there is no substitute.
95% of businesses use some type of cloud-based software, according to a 2018 Cisco study, and this number is likely even higher today.
Security
A Router with a Firewall like discussed earlier is a good step. Another is to keep your POS network segmented from everything else. At your location you might have a back office computer you allow people to use. You might have a guest network for customers to use. IP security cameras and a whole host of different devices could be on your network. All of that traffic should NOT be on the same network as your POS system. There are a few ways to accomplish network segmentation. One way is if your router is capable is to create multiple Virtual Networks or VLANs. This will allow certain parts of your network to be separate from others, but this solution does take some networking know-how. You can also simply put in a separate router. You can take one LAN port from the main router and plug it into the WAN of your ‘POS’ router then plug in all your POS equipment in the ‘POS’ router. This will ensure the POS network is on a separate network. You will want to ensure the ‘POS’ router in this example has a different LAN schema than the main router.
Conclusion
My recommendation is to use ethernet cables everywhere you are able to. In the real world each location has its own layout and needs for the POS. There will be some places that just can’t run wires or there might be mobile POS stations like tablets that can’t be hardwired. In these cases you will need to mix and match hardwired and Wifi. The area where you want the mobile POS tables to work might not be close to where the internet router is. In this case you will have run a hardwire to an Access Point(AP) to a location close to where the tablets will be used. An AP is a device that takes the internet from the router and then emits a wifi signal to a location not close to the router. There are many things you can do on a network but from my experience keeping it simple is the most reliable way. KISS. Having a network professional will help ensure installations are done correctly but you should have some elementary knowledge which hopefully this post gives you.