You should know how to physically disconnect if you need to. The sections below provide help with maintaining your underlying Internet connection, and describe why you might want to break it quickly by physically disconnecting from the network.
Connection. If you are having unpredictable Internet connection problems — random disconnects — the first thing you should do is try a ping test to confirm it’s a problem with the network and not an individual application or protocol. If ping indicates the entire network connection is completely down, or the network is fine but you can’t reach your provider’s website, email server, Usenet newsgroup server, etc, and rebooting everything with a power light doesn’t solve the problem, then you can phone your service provider and see if they are having problems or can provide further assistance. As always, you are likely to get better and faster service when you can describe the tests you have already run.
On the other hand, if your system disconnects after a certain amount of time without use, then either your computer or your service provider might have a default time-out set to close the connection if it isn’t used for a specified length of time. This is often an option in dial-up client settings, so check your own computer’s configuration first. If the disconnect setting is on the network provider’s side, the decade’s old hack to solve this problem is to set up an electronic pulse by configuring your email program to automatically check your server for mail every M minutes, where M is a few minutes less than the default disconnect period, and leave the program running to generate traffic at regular intervals and keep the connection alive. You should try to keep the period as long as possible to minimize the small but real load on the server — i.e., if the disconnect period is one hour, perhaps set the program to check for email every 50 minutes.
Finally, an invaluable component of your Internet connection safety kit is a basic telephone modem to give you a back-up connection method. Whether you are already connecting with a low-speed telephone modem or using a high-speed wireless modem, having a backup modem provides a safety net in case your primary Internet connection goes down due to hardware failure — a rare but frequent event. When your backup connection is also a different method — telephone backup to wireless — it is probably to a different set of servers and a different part of the network, providing additional redundancy. Almost all high-speed providers provide a backup low-speed Internet telephone capability for travelers and exactly these sorts of emergency connections.
Disconnection. Maintaining an Internet connection is all well and good, but sometimes you need to bailout in an emergency and quickly stop some online function but can’t figure out how. For example, you might change your mind while downloading a large file but can’t stop the program, be doing an online program installation that you can’t cancel, or performing some other process you can’t end by conventional means. You could reboot your computer, but you’d rather just quickly and completely cut your network connection.
These are the times to remember that you can always take the low-tech route and disconnect from the Internet by physical means, either by turning your modem off, or by disconnecting your modem cable from your computer. Handheld wireless connections can usually be broken by turning the device off.
Once you disconnect from the Internet, problem programs will sometimes end by themselves or give an error message so you can correct the situation, reconnect to the network, and proceed as you wish. However, if the program stays hung up, then you can always completely reboot your computer and then reconnect to the network, which usually solves most problems.