Your network is really like a 3-layer cake.

The bottom layer is the Physical layer — the hardware, the cabling, the network cards, the router, and so forth.

The middle layer is the Operating System layer — Windows OS controls things like the user accounts, the file system, file-sharing, file permissions, installation and configuration of communications protocols, assignment of IP addresses, etc.)

The top layer is the Application layer — Internet Explorer, Firefox, any other applications that share files, as well as the applications themselves (MS Office, Photoshop, audio apps, video apps, etc.) that generate the files that you want to share.

Here’s why this is important:

If you find that your network is not working properly, you must isolate the source of the problem — and the three-layer concept helps you do that.

1. For example, if you can’t see the neighboring computers, first check the Physical layer — is the cabling plugged in? Is the power to the hub or router turned on? I know it sounds simple, but the Physical layer controls the other two layers. If you have a problem there, you have a problem everywhere.

2. If you can “ping” the other computers but you can’t “see” the other computers in Windows Explorer (for example), or if you can see them but you don’t have access to the shared folders, then check the OS layer — for example, does the other computer have an account you can use to log onto that computer? On the other hand, if you can log on and see the computer and see the file or folder, perhaps the permissions are not set so that you can actually open the file and use it.
3. Lastly, having access to the file is not enough: you might need the actual application that opens the file. For example, if it is an audio file, you’ll need a audio player that can handle the format that the file is in. This is the job of the Application layer.

All three layers need to be functioning properly. And, like a 3-layer cake, you have to build from the bottom up:

• First, the Physical layer

• Second, the OS layer
• Third, the Application layer.

Pass the ice cream.

I’m just saying.