Connecting to a fax line using Modem

Hi,
I want to transfer data between 2 computer. the Receving computer has a fax modem.I tried to dial the receving computer from the send computer using Modem. The call is not getting estabished. I got an information that the telephone exchange wont allow data transfer to the fax line; ie the telephone exchange will cut the call when it see the data in fax line. Only fax data and voice call are allowed in the fax line. Is there a way to send the data making it look like fax data, so that the exchange wont detect that the data is not a fax data.

is there a way to send fAX from VB application

That doesn't sound right to me. They don't charge more for data thru a phone line, unless you want faster than 56K, in which case they offer DSL service.

A PST is a phone line, is a fax line, is a data line.

Thats the truth. extra amount has to be paid if data needs to be transmitted. They do this to block the usage of Internet using the phone line and they want to sell DSL service more :(

Just so you know there is no data transmitted until the connection is established. All that happens is the 2 modems go back and forth to try an find a baud rate, compression and such that both modems can agree on. Once this happens you get a connection and only then is any data transmitted.

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Originally Posted by makdu

Thats the truth. extra amount has to be paid if data needs to be transmitted. They do this to block the usage of Internet using the phone line and they want to sell DSL service more :(

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Not in this country. If you want slow Internet service that blocks out your phone while you're using it, what do they care? They still get paid for every time you use the phone.

I have a server computer and 5 other client computers. I dial each computer using my VB application to send and receive files/data. It works fine with 3 of the client computer and other 2 , i am not able to get it connected. This two computer are connected to a fax line . So when ever i try to dial this two computer from server computer, the exchange detect it as not a fax data and drops the line. I Want to bypass this problem. Is there a way :(

I would suggest plugging the trouble pc into a different phone jack and see if the problem persists

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Originally Posted by makdu

I have a server computer and 5 other client computers. I dial each computer using my VB application to send and receive files/data. It works fine with 3 of the client computer and other 2 , i am not able to get it connected. This two computer are connected to a fax line . So when ever i try to dial this two computer from server computer, the exchange detect it as not a fax data and drops the line. I Want to bypass this problem. Is there a way :(

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Sounds like the answer is NO. Complain to your telco

I am just wondering why you think that the exchange is detecting a data connection and dropping the line. A fax signal is also a data signal btw though it is a bit different. I have never heard of such a thing but I have saw many instances where one would have trouble gettting 2 modems to connect especially when the modems in question are the cheaper soft modems. My guess would be that the problem resides in the modem or the init strings on the pcs giving the problems.

You can easily determine if it is the line or another problem by moving the pc to a different phone line, perferrably one where you have already had success with a different pc. If it works then you can safely say it is a line or jack issue. If it does not work then you need to look for a different problem.

If it is as you say and the phone company not allowing a data connection on the phone line you are using then basically what you are asking is for a way to rip off the phone company by getting a service that you are not paying for which of course would be illegal. What you need to do is either use a different line or pay for the correct phone service on that line.

Tried moving the 2 PC to other connection which was working and the result is that the call and data transmission is happening. So the problem is with the 2 lines only. As mentioed earlier, it has been identified as the telephone exchange is blocking the line when it see a data in the fax line.
:(
One suggestion i got is to make the data transfer looks like that of FAX data and send it through the line and at the time of dialup, use the handshaking method used by fax line .

Can some body differentiate how the data transmission is different in fax and normal data send through Dialup

Depending on what you are actually doing, you may want to reconsider your whole approach to the data transmission problem.

Your current method has problems with perhaps fax lines or perhaps even firewalls if the destination computer is in a network.

When you connect to the destination computer, I presume you want to go to a predetermined directory and pull or send some files

To deal with this basic requirement, I often simply use a website, using an FTP prgram to upload and download the data files (NCFTP is an excellent and reliable FTP program)

By using the website as the "HARD DISK" of your client computers, you can create a directory for each computer on the website, and simply download the data from these (each client send data up at an agreed interval)

This will eliminate all possible problems of getting through to client computers through the various "WALLS" which can be placed in front of you

You will also find this to be faster and less prone to transmission problems

Once you play with NCFTP using the many examples provided you will wonder why you have been bashing your head against the brick wall for so long - its so simple and reliable to use

On the other hand, your managers may prefer your current approach, so I guess you would need a good helmet (LOL)

If the phone line does not allow data and ftp connection via the phone line would not work either.

If the computers are networked then the winsock control is a much better choice than MSComm, very easy to use, built in protocol only need a few lines of code.

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Originally Posted by George1111

On the other hand, your managers may prefer your current approach, so I guess you would need a good helmet (LOL)

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I need a good helmet :). Has to find a way to send the file, not through FTP .

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Originally Posted by DataMiser

If the computers are networked then the winsock control is a much better choice than MSComm, very easy to use, built in protocol only need a few lines of code

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I have asked for this option. But will take time to get it done. Still insisting to find a way through fax line :(

Is there a way/ code to convert a normal text file to a fax data ?

I suppose you could print it to a fax driver, getting the data as a text file on the other side would likely prove difficult.

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Originally Posted by DataMiser

I suppose you could print it to a fax driver, getting the data as a text file on the other side would likely prove difficult.

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Tried this option by sending a text file. But the receiving file is a tiff file:( Is there a way to receive the file in the same format as we send, ie txt file as txt itself or doc file as doc file itself ????

a fax is basically a hard copy so I would say at best it would be very difficult but odds are that it is near impossible.

Why not tell your boss that he will need to upgrade the phone service if he wants to send dat to these computers

IS there a way to achieve the result using TAPI?, ie instead of using MSCOMM, if i got with TAPI programming, will that solve the connection problem?

Think about it. If you are using a phone line and you need to send data but the phone line does not allow you to send data then you are spinning your wheels.

You need to get either the proper phone service on the line(s) in question or use a method other than the phone line.

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Originally Posted by DataMiser

Think about it. If you are using a phone line and you need to send data but the phone line does not allow you to send data then you are spinning your wheels.

You need to get either the proper phone service on the line(s) in question or use a method other than the phone line.

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correct :) i missed the reason for the problem and was thinking of a way to get a soultion :(, (desperate attempt)

Kind of like wanting to get money out of a copy machine? We couldn't tell you how to do it. Others would figure it out as well.

I doubt they're protecting their fax lines. I'd guess voip lines.

How is a music file send through the line, will it be same as data signal or different. If it is different, i think i can give a try by sending a .mp3 file and check the behaviour. Whats the opinion on this ?
The reason i want to have a try is that the voice communication is happening with this line. So if the music data file is different from normal data, then the line should support sending the file .

Whats the way of handshaking done when a fax line is dialled from MSCOMM. Is that different?

When you send a fax the modem uses different tones to identify itself to the remote modem. A fax machine can answer an incoming fax request but will not connect to an incoming data request.

As I understand it when you send a fax you are basically sending a digital image that can be printed on the receiver side. A data transmission sends a data stream. This can be anything at all, music, video, text files, binary files or whatever. The onyl thing that is different is the actual data being sent.

Handshaking as pointed out before is simply the start/stop signals and have nothign to do with the type of data being sent.

Have you considered an AB switch

When in A mode the Fax line is connected to the Fax

Wehn in B mode the Fax Line is just a telephone line connected to a normal Modem

Hopefully then, the Fax machine wont interfere when you are in B mode


OH !!!! I JUST HAD A REVOLUTIONARY IDEA

Install another line just for the comms and forget about using the Fax Line (other than for faxing)

This will cost a about $20 a month no doubt - too much for your management ?

(so far your free consultancy would have cost your management about $2000, I would guess - but thats the wonderful guys at Codeguru - cheers !)

You did say non-fax lines were working well, I believe - this just may be a solution when there doesnt seem to be another solution forth coming.

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Originally Posted by George1111

Have you considered an AB switch

OH !!!! I JUST HAD A REVOLUTIONARY IDEA

Install another line just for the comms and forget about using the Fax Line (other than for faxing)

This will cost a about $20 a month no doubt - too much for your management ?

(so far your free consultancy would have cost your management about $2000, I would guess - but thats the wonderful guys at Codeguru - cheers !)

You did say non-fax lines were working well, I believe - this just may be a solution when there doesnt seem to be another solution forth coming.

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Its more than $20 and not just one shop. So yearly cost will be more than around $10000. And the management dont want to go with a new line option (:( bad time comes in unexpected fax lines ).

Have you tried using the target PC to receive a FAX from your computer on that line? I've seen lines where the quality is so poor, that certain types of data connections can't establish themselves. Perhaps lowering the baud rate will work too, in the case of poor line quality. Try something like 1200bps. That **should** be low enough for just about any line.

I would tend to agree however, that data is data, and I have my doubts that the telephone provider is detecting the nature of the data, and cutting the connection.

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Originally Posted by WizBang

I would tend to agree however, that data is data, and I have my doubts that the telephone provider is detecting the nature of the data, and cutting the connection.

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You got the problem. The telephone provider is detecting the nature of data and cutting the connection

So what you want us to do is come up with a way to trick the telephone provider in your country ?

Is that it ?

(Personally I totally agree with Wizbang that bits on a line are bits on a line - not a tiff - not a jpg - not anything until they get deciphered at the other end. No telephone provider is going to intercept a string of bits and then try to decipher what they may be, just so they can allow them through or reject them)

What country is this where the cost of a telephone connection costs thousands of dollars and when you have a line installed it can only be used for one purpose ?

I think somewhere here the facts are not adding up.

Could I suggest you test the theory that a Fax Line is only for faxes by plugging a phone in each end and trying to talk using the fax line (voice is not the same as fax data so by your theory should not be allowed on the line)

Also try plugging a computer into the fax line and try dialing up a dial up internet provider - I am sure one of your collegues can supply you with a dial up number just for testing, since broadband connections in your country must cost a bundle.

At some stage you may have to tell the "management" that their expectations are unrealistic - and your abilities are not the problem (you certainly are tenacious which is a worthy quality for a programmer)

I hope you are not in a country where they chop off your head for failure :)

Maybe the problem is the modem.
You said, "the receiving computer has a fax modem", so it will only connect to another fax modem and that is the problem. Not the line is rejecting the connectiom, but the receiving fax modem does not find there is a fax protocol incoming and rejects the connection.
Simply try to use a normal modem at the receiver's side and no matter what nature the line is, you should be able to connect.

WOF Said

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Simply try to use a normal modem at the receiver's side and no matter what nature the line is, you should be able to connect.

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This is along the lines I suggested previously

Use an AB switch to switch the line from one modem to another, or perhaps you can purchase a modem which allows both data and fax streams to co-exist without problem.

If I understood correctly we are talking about a data/fax modem. It also seems that this is the line that he has to work with at this location. If it truly does not allow a data connection then there is no coding solution that I am aware of.

I've seen fax modem cards which were incompatible with other modems and/or stand-alone fax machines. So it wouldn't surprise me if the problem is the card.

Attempting to connect to a remote server via telnet may be revealing.

In Post #11 he says that he moved the 2 troubled PCs to a different phone jack and they worked. If that is the case then it rules out the modem and the software. Only thing left is line/jack

In a few posts it is mentioned that the phone company does not allow data connections on the phone line in question. If this is also true [surprising but never the less] there is nothing he can do other than use a different phone line or change the service on the existing phone line.

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Originally Posted by DataMiser

In Post #11 he says that he moved the 2 troubled PCs to a different phone jack and they worked. If that is the case then it rules out the modem and the software. Only thing left is line/jack

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Yeah, that's true. Though I've also seen some modems have more trouble establishing a connection on poor quality lines than others. So although it does appear to be the line, that in itself doesn't mean the connection is being purposely cut.

If the company really is detecting the nature of the data, I have to wonder how close that gets to eavesdropping.

Used to be, that some cable TV companies tried to charge people extra if they hooked up multiple TVs. The FCC eventually ruled in favor of the consumer, for obvious reasons. I doubt it is so different with telephone companies, that they'd be allowed to mess with a customer's connection based on the data being sent.

makdu, can you tell us in what country this is happening? How long does the connection last before it is lost? What baud rates have you tried?

send a fax from a computer modem, to the other computer modem. see if that goes thru. otherwise, complain about it

Did you try this ? (as previously suggested)

Could I suggest you test the theory that a Fax Line is only for faxes by plugging a phone in each end and trying to talk using the fax line (voice is not the same as fax data so by your theory should not be allowed on the line)

Also try plugging a computer into the fax line and try dialing up a dial up internet provider - I am sure one of your collegues can supply you with a dial up number just for testing.

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Originally Posted by WizBang

makdu, can you tell us in what country this is happening? How long does the connection last before it is lost? What baud rates have you tried?

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country is Kuwait. Baud rate tried is 9600

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Originally Posted by George1111

Did you try this ? (as previously suggested)

Could I suggest you test the theory that a Fax Line is only for faxes by plugging a phone in each end and trying to talk using the fax line (voice is not the same as fax data so by your theory should not be allowed on the line)
.

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Voice call is going :(

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Country is Kuwait

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Ah ... so you will lose your head if you fail

We better solve your problem quickly then !!!! :)

(Sorry I cannot help any better)

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Originally Posted by makdu

country is Kuwait. Baud rate tried is 9600

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OK, try a baud rate of 1200. Slow, yes, but if it works...

Also try telnet. Maybe try windows messaging too. What about remote desktop or pcAnywhere? That would be interesting to see.

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Originally Posted by WizBang

OK, try a baud rate of 1200. Slow, yes, but if it works...

Also try telnet. Maybe try windows messaging too. What about remote desktop or pcAnywhere? That would be interesting to see.

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Thank you all for the help. I am making another setup to test all your suggestions. I will give you a result for each of the test done by tomorow. Hope this test will give me more data to resolve the problem

Thank you all. You all saved my head :)

This thread can now rest in peace. The idea to send data through fax line is aborted. Lot of testing is done and found that the problem cannot be bypassed without the signal being detected as data signal