This requires lots of experience, in the quest for potential problems.
Some things you can do is:
A File Server
Answer: File
File Server
This may be a problem with the server (which is not solvable by the user), or it may also be a connectivity problem. Try restarting your system and checking the connectivity.
To troubleshoot connectivity issues with a router, start by checking the physical connections, restarting the router, and ensuring the settings are correct. If the issue persists, contact your internet service provider for further assistance.
PING, Netstat & Tracert
If the server crashes and you are remote, then there is no connection to troubleshoot unless you can get someone on the phone at the site to help with problem analysis.
The job description of a file server can simple be found online on sites such as 'Wikipedia', which explains the mechanics of a file server or 'FileServe'.
communications server
Yes. For your client computers to access the files on your file server they need to be able to communicate with the file server which is where the LAN comes in because it interconnects all your computers and the file server so that they can communicate.
CM TS device refers to the Connection Manager Test Server device, which is used for testing network connections and services. It allows users to simulate network conditions, troubleshoot connectivity issues, and test application performance in various network environments.
One can find information regarding WSUS download errors on the support section of the Microsoft website. They have trouble shooting guides on the subject and forums one can use to get help from other users.