The best trick to troubleshooting
Please do not throw sausage Pizza away!
No, you did not read the above wrong; this is an acronym that IT teams use to troubleshoot issues with your computer and your network connections.
How does Sausage Pizza relate to Information security? This acronym helps to remember the layers of the OSI model for step by step troubleshooting.
How would I use this??!!!
The OSI model can be used as a step by step checklist to troubleshoot computer or internet connection issues that you have. Once you know where the problem lies, you can now understand what to fix with the help of some Google-Fu.
OSI, Layers, what?
OSI, which translates to The Open Systems Interconnection model, is a reference guide that was developed in 1978 by Hubert Zimmermann to help teach computer networking concepts on how data moves between the seven networking layers.
So what does the acronym stand for?
Please (Physical), Do (data), Not (network), Throw (transport), Sausage (Session), Pizza (Presentation), Away (Application)
Physical - This consists of printers, computers, ethernet cables, printer cables, modems, etc.
Data - Represents the information that is transferred between devices; for example, a document you send to the printer.
Network - Represents how the data in your home move between your devices. Your modem/router uses your IP address is used as an identifier to know where to send data. Think of it as how UPS knows where to deliver your package, and your IP address is your street address.
Transportation - Is the data that is sent to outside of your network, for example, when you type in a website address into your browser that millisecond it takes to load is this layer in action. Internet speed test function at this layer when checking your speed
Session - Manages the flow of the data between computers and networks; this is the internet, a bunch of networks connected.
Presentation - This layer deciphers the data so that the next layer in the OSI model can translate it. I like to think of this layer as a projector, and it converts the stills of the film to a full-motion movie.
Application - This is the screen that moviegoers view the film on. This layer takes all that data that is sent back and forth between layers 4, 5, and 6, makes it viewable for us the user. Web browsers, Netflix, and email clients like Outlook are all listed on the Application level.
In this example, the HTML code in the red box becomes the site above.
Here is a recent example of how I used OSI.
A friend of mine was having trouble accessing the internet.
The first thing I did to troubleshoot was to make sure the modem and router was connected the modem connected, and the wiring was attached correctly(Physical).
Next, we checked that the computer was communicating with the router (Data). You can do this by going to your routers admin page, as I mentioned in my first blog. If you can connect, then everything is fine (Data/Network).
This is when we found out what the issue was. The issue was that the computer kept disconnecting from the router when we were in a different room, but when we were in the same room as the router we did not see any issue with connection to the router. From there, I was able to deduce that the layout of the apartment was affecting their Wi-Fi signal.
At this point, I suggested that they get a Wi-Fi extender to amplify the signal. Quick, easy, and no need to call your cable company
Now I have to build that Wi-Fi extender. But that is a separate blog.
In summary the OSI model is helpful because it gives use a check list to of issues that can cause your devices to have connection problems. This will eliminate the need to contact your telecommunication provider with unnecessary back and forth conversations.