Tuesday, November 11, 2014

Article Number: 9983


DEFEATING CALL WAITING - If you use a MODEM for telecommunications, you may



have been told that you cannot have the Call Waiting service offered by the



phone company. Call Waiting is a service that permits you to receive a call



when your line is already busy. If you are talking to someone on the phone, and



someone tries to call you, you will be momentarily disconnected from your first



conversation and connected to a "beep" tone. The person on the other end will



hear a moment of dead silence (as if you had depressed your phone switchhook for



about half a second). Note that the Call Waiting tone is NOT superimposed upon



the conversation in progress, rather, the existing connection is momentarily



interrupted while the Call Waiting tone is online. You then have the option to



hang up, in which case the original connection will be broken, your phone will



ring, and you can answer the second call, OR you can switch between calls by



momentarily depressing the switchhook - one caller will be on"hold", and you can



talk to the other.





This service works reasonably well on voice circuits, but when a phone line is



used for both voice and data, some problems arise. For one thing, when a MODEM



is in use, it is usually not possible to hear the Call Waiting beep tone, thus a



second caller would probably never be answered, and might incorrectly conclude



that no one is at home. However, in some circumstances, the momentary



interruption of the circuit may cause one or both of the MODEMs in use to drop



carrier and disconnect, or at very least may garble the data being transmitted.



IF a commercial service or a Bulletin Board System is being accessed, the



momentary carrier loss will almost always cause a disconnect (and if you are



paying for the service, you may incur an extra charge because you didn't



terminate the call properly).





Unfortunately, many of us can't afford to have a separate phone line for our



computer, so the question is, how do we defeat Call Waiting while our computer



is using the phone? You may have been told that it's impossible (especially if



you asked someone at the phone company), but that's not so. However, you must



have one additional "Custom Calling" service - either Call Forwarding or Three



Way Calling - for this to work.





Before I describe the methods, I'll just state that the reason they work is



that no matter how many "Custom Calling" features you have, your line will only



handle a maximum of two calls at once. In other words, if you have two outgoing



calls in progress on Three Way Calling, an incoming call will receive a busy



signal even though you also have Call Waiting.





The easiest method involves using Call Forwarding, providing you can fine a



"permanently busy" number in your area. Most exchanges have one or more numbers



that ALWAYS return a busy signal (in Michigan, for example, numbers ending in



"9999" are often permanently busy). If you have friends in the phone company,



they may be able to give you a permanently busy number. All you do is to set up



Call Forwarding to forward all your incoming calls to that numbers. Callers



receive a busy signal, and your line is not interrupted by Call Waiting. In



some areas, you may be able to Call Forward calls to your own number, which



would have the same effect (busy signal), or (less desirable) to a number that



you are absolutely sure will never answer - perhaps a business you know is



closed (this would give callers a ringing signal). Or, you could even forward



calls to a friend, who could explain to callers that you're using your MODEM,



and either take messages or ask callers to phone back later. Once you're



through with your MODEM calls, be sure to cancel the call Forwarding!





If you have Three Way Calling, you can place a call to a "permanently busy" or



"permanently no answer" number, then press the switchhook momentarily to get the



second dial tone, and then dial the number you want to call with your computer.



The problem with this is that some phone companies have "timeouts" that will



automatically disconnect a line that has been connected to a busy signal or no



answer for a given amount of time. When the number disconnects it will



momentarily interrupt your MODEM connection - the very condition you're trying



to avoid! So, it may pay to experiment with a few numbers to see which will



time out, and which won't. For example, it may be that on your exchange, busy



signals will time out but "invalid number" recordings won't. Try dialing a



local with a "1" in front of it, and see if you get a recording telling you not



to dial the "1" (or try the opposite a long distance call with no "1"). That



may get you a recording that will not time out.





When you use the Three Way Calling method, there is an additional disadvantage



in that if your MODEM call is busy or does not answer, you will have to set



everything up again next time you try to call. In contrast, Call Forwarding



remains enabled until you specifically disable it.





You may find it advantageous to have BOTH Call Forwarding and Three Way



Calling. This way, if someone calls YOU and wants to upload something to you



(or you want to download to him), you call first excuse yourself, go onto Three



Way Calling, and program your Call Forwarding from there, so that you won't be



interrupted. Otherwise, you would have no way to set up Call Forwarding once a



call is already in progress.





Of course, by the time you have Call Waiting, Call Forwarding, and Three-way



Calling, you'll be paying a pretty hefty monthly charge to the phone company.



So you may find that getting rid of the Call Waiting is an attractive



alternative. Or, perhaps you can limit your MODEM calls to after midnight, when



no one in their right mind would be calling you anyway (of course, you may know



a few folks that aren't in their right mind, or maybe you have a reputation as a



night owl, like most computer hackers).





Please note - the above methods of defeating Call Waiting are suggestions



only. I assume no responsibility if your phone company gets mad at you for



actually using one of them. HOWEVER, if the DO complain, you might suggest to



them that if they are going to sell such a service, they might consider



providing a way (maybe a one or two digit code) that people can temporarily



disable it, so that important calls would not be interrupted. Even if you're



NOT, using a MODEM, it is an awful nuisance to have a long distance call



constantly interrupted by Call Waiting - which is probably one reason the



feature isn't more popular than it is!





This article re-printed from NORTHERN BYTES Newsletter.





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