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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