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View Full Version : Give me a lesson in Dial-up infrastructure (Please)



ASM
August 4th, 2012, 05:21 PM
Hello everyone,

So recently I have been getting into vintage technology and what better way to connect to the internet than dial-up right?

I have acquired an 8-bit ISA modem for my (soon to be delivered) personal computer which got me thinking, I am really not too clear on how the internet functions aside from the basic protocols and such.

So, what I really wanted to draw from this thread is how two computers establish a connection and communicate via dial-up. I would assume you use the local phone line to send a bit stream to the phone exchange where an ISP will redirect your traffic to the other IP (Not sure if correct, just making an assumption). Some of my confusion relates to how the ISP can locate the IP of the other device; I assume that the IP has an indicator pointing to where they are located which enables them to establish a connection. This got me thinking and I am now unsure why it is not possible just to directly connect to an IP using a phone line, I am not sure what is stopping you or why an ISP is needed in the first place. I suppose this would be going into the realm of creating your own dial-up ISP (again, not sure if possible).

Thank you for any useful information you can provide me with!

mbbrutman
August 4th, 2012, 05:29 PM
Google is your friend.

http://en.wikipedia.org/wiki/Dial-up_Internet_access


And many more after that ...

Ole Juul
August 4th, 2012, 10:16 PM
I would assume you use the local phone line to send a bit stream to the phone exchange where an ISP will redirect your traffic to the other IP (Not sure if correct, just making an assumption). Some of my confusion relates to how the ISP can locate the IP of the other device; I assume that the IP has an indicator pointing to where they are located which enables them to establish a connection. This got me thinking and I am now unsure why it is not possible just to directly connect to an IP using a phone line, I am not sure what is stopping you or why an ISP is needed in the first place. I suppose this would be going into the realm of creating your own dial-up ISP (again, not sure if possible).

I see a lot of confusion there. :) Like Mike suggests, some reading about the internet might be a good thing. I have a couple of things that might help clear things up at this point though.

The phone system is different from the internet.

When you use "dial-up", you are making a phone line link to the ISP who is the one connected to the internet. The phone line link to the ISP is on a piece of wire and is basically audio. That is why you both have modems - modulate, demodulate. You are just modulating a tone with a digital control and the ISP is demodulating it back to digital.

You can easily connect two computers on the phone system. Just dial them up with your modem (usually Alt-D) and you can transfer files or chat. Just remember, that although you are both using a computer, you are not on the internet when you do that. You are on the phone.

When you get your modem installed and load a terminal program, you are welcome to call my house and we can chat. Try "lync" which is small and simple. I've put it here for you. (http://cgs.coalmont.net/lync32.zip). It only takes me a couple of seconds to go into host mode, but I keep unusual hours, so let me know ahead of time.

ASM
August 5th, 2012, 02:27 AM
I see a lot of confusion there. :) Like Mike suggests, some reading about the internet might be a good thing. I have a couple of things that might help clear things up at this point though.

The phone system is different from the internet.

When you use "dial-up", you are making a phone line link to the ISP who is the one connected to the internet. The phone line link to the ISP is on a piece of wire and is basically audio. That is why you both have modems - modulate, demodulate. You are just modulating a tone with a digital control and the ISP is demodulating it back to digital.

You can easily connect two computers on the phone system. Just dial them up with your modem (usually Alt-D) and you can transfer files or chat. Just remember, that although you are both using a computer, you are not on the internet when you do that. You are on the phone.

When you get your modem installed and load a terminal program, you are welcome to call my house and we can chat. Try "lync" which is small and simple. I've put it here for you. (http://cgs.coalmont.net/lync32.zip). It only takes me a couple of seconds to go into host mode, but I keep unusual hours, so let me know ahead of time.

Thank you for the answer!
It has been very helpful.
I have a few more questions but I have to leave for a little while, be back soon.
Thanks again.

Bungo Pony
August 5th, 2012, 04:38 AM
For software, I usually use Telix even though it's not Y2K compliant. When I don't feel like making an entry in the dialing directory, I'll just type ATDT followed by the phone number.

I've done things like used calling cards and blocked my number. If you happen to find a BBS and want to use a calling card to phone it, you may have to add in things like commas for pausing. For example, if I wanted to dial a long distance BBS and block my number, I would enter ATDT1167,,12045551212