Phone/Modem Switch
18 messages in this thread
I want to run a BBS, but I hate the phone company. I was looking at the
switchs that listen for a modem carrier, and then switch the phone call to
the modem.
Do they work? Do they work with all modem carriers (incl.
V32/V32bis/HST)? Or is their just one inital carrier tone for these
modems??
Alan Russell
Alan,
The answering modem sends out the tone at first…not the
originating modem. Not sure how faxes handle it….but for communications
work (BBS's) I don't believe and auto-switch would work.
Don
Some fax machines send out "CalliNG" or CNG signals while waiting for a
response from the "called" number. Most voice/fax switches will recognize
this signal and route to the fax device. If the "calling" fax machine does
not emit CNG signals then the fax switch must have some type of fallback
procedure to route to the fax. This is usually done with a time interval
or a touch tone code from the "calling" device.
Modems however, muck up the procedure since they are very much like fax
devices and not different enough to be sensed by a voice/fax/modem switch,
which to my knowledge is the only type of switch that will help you – ie.,
I am not aware of any voice/modem switches. I use an ASAP TF 555 switch
with a voice line and Telephone Answering device or TAD, a Fax machine, and
a computer modem connected through it. If someone calls my number and they
are using a fax machine with CNG signals, then the call will be routed to
the fax. If the fax machine does not emit these signals, then my TAD will
pick up the line and give a message outlining how to access the fax machine
with touch tone, or to leave a message. I also have the system configured
to connect to the fax machine after the TAD has done its thing so the
caller can just hang on in order to send a fax. The switch will only
recognize a "calling" modem if the modem was dialed in REVERSE mode, ie, it
was dialed in ANSWER mode instead of ORIGINATE mode. This is outlined in
your modem docs and involves appending an 'R' to the end of your dial
string, eg, "ATDT 555-1212R". Then the switch will automatically route to
the computer when sensing this call since the "calling" modem, not the
"called" modem will start emiting tones. The only kicker to this is that
the "called" modem, in this case your BBS must be able to ANSWER in REVERSE
mode also, ie., pick up the phone in ORIGINATE mode instead of the default
ANSWER mode. At this time this parameter can only be changed on the HAYES
Ultra and Optima modems. The other option would be to have your callers
append the touch
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tone codes to switch to the computer modem. Let's say your code was 25
then the callers would use a dial string of "ATDT 555-1212,25,25,25". The
commas are timed pauses and the repeating of the 25 is to make sure the
switch gets the code. In my opinion, either of these options make
unreasonable demands on your callers since the information necessary to
make the connection may not be properly disseminated. You may hate the
phone company, but it you want to "modem around" there are not too many
options available to you. A second non-published line on your current
phone account is cheaper than a totally separate line account, and will
keep your voice line clear for calls.
-John-
Thank you for your thoughful reply.
I guess I will have to wait to have my bbs..
Alan Russell
Another option is the special ring service (called RingMaster in my area)
that is offered by the phone company. What this allows you to do is have
more than one telephone number attached to a single line with each number
having a distinctive ring.
I have already seen some shareware on the PC side that will allow you to
use your PC to screen out which calls are data calls and which are voice
calls using the appropriate ring sequence. If you were using a FAX modem
then you would be all set.
RingMaster is an added telephone charge, but it is much less than another
line.
Bill
– via Whap!
Absolutely and an option that I had not thought of.
-John-
Bill, this 'RingMaster' you're talking about…. does it allow a couple
(2-4) calls at ONCE, or can only one line be used at a time? ie. If I
wanted to set up a 2line BBS, could it be used in leiu of a 2nd phone line?
Thanks….
–jp–seattle–
John, No, it doesn't allow multiple calls at once. All it does is have
different phone numbers assigned to the same line. Each phone number
causes it's own distinctive ring (much like the old party line system — my
calls are 2 long rings, yours is 1 long 1 short, someone else's is 2
shorts, etc.).
-sja
Oh well. Was just looking for a cheaper way to have two independent lines.
Thanks.
–jp–seattle–
Other than stealing service, I'm afraid that the "Baby Bell" in your area
has "got you by the punch block" on separate lines.
It only allows one call at a time. It really doesn't give you a second
line, it only provides information (via a distinctive ring) on which number
was used to access this line. But, if you simply want to set up a BBS for
a very limited number of people then it might be acceptable.
Bill
– via Whap!
Thanks. The application I have in mind would require -2- phone lines, it
sounds like. Oh well. 2nd lines aren't soo much 🙁
–jp–seattle–
Bill,
There is a similar phone company feature in my area, altho it's called
something other than Ring Master. What I'd like is a hardware box that
will determine what the ring sequence is then route the call to fax,
computer or phone/answering machine.
-sja
Steve–
I wish you had posted your message a couple of days earlier…I was at the
local computer fair (where PC clones of dubious origin go for unheard of
prices – loaded 486s for $1700-1800…saw many a face from the local Amiga
group, turning coats…:( ) and I saw the very item you are looking for. Of
course, at the time, it drew nothing more than a ho-hum from me, and I did
not take down any details. But, the device does exist…i.e., something
that will be able to distinguish different ring patterns from
Ringmaster-like setups.
Jonathan
– via Whap!
Heath makes a box that understands the special rings. See my message in
Amiga Hardware – so I got the wrong section when I posted the message!
The box cost $150US.
The software that I have seen on the IBM side will allow you to use your
modem to screen calls via the ring service to your computer or telephone.
How it works is you "train" the software by having someone dial the number
that should access your computer and let it ring. The software then
records the sequence of rings that signify a "data" call. The modem will
then answer only when this particular ring sequence is encountered,
otherwise it wont answer and that will allow you to pick up a phone or have
an answering machine pick up.
If you were using a FAX modem then your modem could handle FAXs or BBS type
calls and allow voice calls to be handled normally. So it accomplishes
exactly what you desire without having to purchase an external box.
I have a copy of the IBM shareware version (its semi-crippled) somewhere.
I will find it and give you the name so you can read over it. I'm certain
that with the new FAX boards coming out, someone will write a similar
package for the Amiga.
Bill
– via Whap!
well, i've called this one bbs that was hooked up to that kind of setup.
here's how it works: when you call, it picks up and says "If you would like
to reach the phone, say 'TELEPHONE' at the beep. If you'd like to access
the fax machine, stay on the line." (they used to run a fax machine on that
line) Then it beeps and a few seconds later, you hear the bbs' modem beep.
so there is such a thing out there. i just do not know what it's called…
🙂 sorry.
bob
– via Whap!