uukx@vax5.cit.cornell.edu (04/02/91)
Can someone explain how those fax/modem/voice line switchers work? Especially the modem/voice part. How can a device determine whether to route a phone call to a modem, or to the telephone, and how does it ring the phone once it has picked up the phone and determined it was a voice caller? Also, is it transparent to the caller on the other end? I am wondering if it would be practical to buy one of these devices to run a BBS on a single phone line...Besides the inconvinience of having the line tied up, would it be possible for voice callers and modem callers to use the same line hamoniously? Any info would be appreciated...thanks -Stephen
py@meadow.uucp (Peter Yeung) (04/03/91)
In article <1991Apr2.015541.3801@vax5.cit.cornell.edu> uukx@vax5.cit.cornell.edu writes: >Can someone explain how those fax/modem/voice line switchers work? Especially >the modem/voice part. How can a device determine whether to route a phone call >to a modem, or to the telephone, and how does it ring the phone once it has >picked up the phone and determined it was a voice caller? Also, is it >transparent to the caller on the other end? > There are, in general, 3 types of such switch and they typically treat voice and modem the same: (1) a synthesised voice will ask the called to press some code on a touch tone phone to indicate whether it is a voice call or something else. If it has 3 ports then it can handle voice/modem/fax. (2) the switch answers the call and check for the incoming fax tone (newer fax machines always generate an id tone when calling), if a tone is detected within a certian period then it switches to the fax port, otherwise it switched to the voice/modem port. (3) the switch identifies the incoming call by a distinct ring. The "distinct identification ring" service must be available in your area. When you subscribe to the service, you will have another number on the SAME phone line. When a call on the new number comes in, it will have a different ring (2 short ring instead of 1 long ring) such that you or the switch can tell which number was called. I have the third type but somehow it does not work for me (going to check with the store see if anything can be done). According to the store, all units sold seemed to work B-( >I am wondering if it would be practical to buy one of these devices to run a >BBS on a single phone line...Besides the inconvinience of having the line tied >up, would it be possible for voice callers and modem callers to use the same >line hamoniously? > >Any info would be appreciated...thanks >-Stephen I think type (3) switches may work for you (see the note on my experience) since it does not care what is actually calling. Type (2) switches can only tell voice calls from fax calls. I think some can handle modem call as well but the caller has to send a touch tone to id it is a modem call instead of a voice call. I have only seen type (1) switch once and it is usually not too popular. -- Peter Yeung Amdahl Canada Ltd., Software Development Center 2000 Argentia Road, Plaza 2, Suite 300 Mississauga, Ont. L5N 1V8 Phone: (416) 542-6300 Fax: (416) 858-2233
py@meadow.uucp (Peter Yeung) (04/05/91)
In article <1991Apr3.153518.7049@meadow.uucp> py@meadow.UUCP (Peter Yeung) writes: >In article <1991Apr2.015541.3801@vax5.cit.cornell.edu> uukx@vax5.cit.cornell.edu writes: >>Can someone explain how those fax/modem/voice line switchers work? Especially >>the modem/voice part. How can a device determine whether to route a phone call >>to a modem, or to the telephone, and how does it ring the phone once it has >>picked up the phone and determined it was a voice caller? Also, is it >>transparent to the caller on the other end? >> > >There are, in general, 3 types of such switch and they typically treat >voice and modem the same: > > ... description of type (1) & (2) deleted ... > >(3) the switch identifies the incoming call by a distinct ring. The "distinct > identification ring" service must be available in your area. When you > subscribe to the service, you will have another number on the SAME phone > line. When a call on the new number comes in, it will have a different > ring (2 short ring instead of 1 long ring) such that you or the switch > can tell which number was called. > >I have the third type but somehow it does not work for me (going to check >with the store see if anything can be done). According to the store, all >units sold seemed to work B-( > The first unit I bought does not work with the "distinct rings" in my area. That unit requires the distinct ring to be less than 1.5 sec (regular rings are 2 sec. followed by a pause of 4 sec.). Somehow, the distinct rings in my area is two long rings with a short pause inbetween. The store I bought the unit form referred me to a manufacturer of another model which is not being carried by them. That model adjusts to different types of distinct rings as long as they are different enough from from the regular ring. It works fine now and I recommend it highly, their address follows. UNiPLUSE International Inc. 60 West Wilmot Street, Unit 17 Richmond Hill, Ontario Canada L4B 1M6 Phone: (416) 886-5659 Fax: (416) 886-5455 The sales manager there took his time to explain to me the whole bit of "phone rings" and the principle of their units. Disclaimer: I am not related to them in any way, I am just a satisfied customer. -- Peter Yeung Amdahl Canada Ltd., Software Development Center 2000 Argentia Road, Plaza 2, Suite 300 Mississauga, Ont. L5N 1V8 Phone: (416) 542-6300 Fax: (416) 858-2233