As a formal or informal network manager, you're often on your own when you're trying to find and fix a problem on your LAN, but if you or one of your users discovers a problem using the Internet, you might need help from your Internet service provider's (ISP's) support center and the people who run the computer or network at the other end of your connection.

Therefore, you should find and keep the telephone numbers and email addresses of the ISP's help desk and the network tech center at the telephone company, cable TV service, or other company that provides the physical connection between your own LAN and your ISP. The people who answer calls in those support centers are there to help you, and they will often have tools that can test and monitor your network connection. When you talk to a support representative, ask for the case number or trouble ticket number that they have assigned to your problem; if you have to call back later, the case number will lead the person who takes your call to the notes about earlier calls.