paperovyy.site
Published: 14 Aug. 2025
• Intro
• Personal Story
• Main Thesises
• My personal attempt
• The simpliest Cisco config using Voice modules
• Other options
This post uses the date before this site was created.
This article was written under few weeks and is a compilation of my brief experience. I've edited this page few time and it is still incomplete, watch for updates or navigate the website for a new followup.
Greeting, visitors. I've been away for quite a long time since many things changed in my life including a new job that I just got and you should take this as a quick come-back while I'll try to reorganize my room... or if I'll be forced to. (Edit: I did have to move out shortly after x#)
Anyways, as you may have seen on my BluSky page, I did a thing I really wanted to do for a while - performing a dial-up connection in the modern time a.k.a. in 2020-ies. That's exactly why I put an X in the title, since I've seen few tutorials how to do it in the past years. Well, that video which I've uploded to my personal YouTube channel is just a demo what you could do with it and honestly it's aint' that special - it's the same Internet connection, just very much slower. As for devices without any Ethernet ports but a whole modem built-in or simply a COM port with an external modem, or installed internally as a card - that will be perfect for transferring files, playing some old multiplayer games and... well... accessing the web, but I'm not sure many (not all, but many) users would be able to find anything era-appropriate that will run atleast good on an old machine.
For those who did some researching or... expect me to write few articles in the near time (I may will): here is what I came up with.
Stuff you need:
A pair of PC's to act as server-client respectively.
A pair of dial-up modems.
A middle-man device to wire modems together.
I did it based on Cisco 1861 Integrated Services Router, because I happened to have it (you should get something better), it has 4 FXO, 4 FXS, 8 PoE Ethernet ports, 1 RJ45 for uplink and another one for extension (no idea what's that). It is not a server in our case, today it will act as a phone line provider.
1. VoIP sucks. It will work for Faxing, like T.38 protocol, but for Dial-up it will ruin the signal. A popular Cisco SPA-122 (or 112) supports "Fax over IP", which uses similar signals, but not the same. CathodeRayDude has a great guide and a theory intro for this device and dial-up, which I've referenced few times in this article. However these ATAs have a big disadvantage (which is quite logical but) it shuts off a voice system when there is no Internet connection, which is quite bad since you may not need any after the setup. On an old firmwares (1.0.1) sometimes it fails to get into the network, not even an IVR can help, unless you give it a kick with a factory reset. I've updated the firmware to the latest version (1.4.1SR5) and it ran quite better and it has added some functionality to it. Thankfully, there is a configuration backup/restore feature, which I haven't used yet, but it may help if your ATA fails just like mine.
Edit: Mine still does it, that thing just really does not want go into my local network. I'm not sure why, maybe it is indeed fried.
There are some things Gravis didn't mention in his article, but some websites did, however I wanna point it out:
a) "Modem Line" option had no effect to me. It alone didn't fix the quality of signal.
b) Set "Jitter Level" to LOW, instead of HIGH. It had increased the baud rate from freaking 300bps to 28.8k. It's really close to 33.6k, which is the max we can get on home modems. And it may vary from one connection to another, from 21k to 28.8k.
c) Also don't forget to use 5V 2A DC power supply, not 5V 1A, as CRD mentioned. Otherwise ATA will die as soon as ring appears.
d) and avoid ATA's which are locked to a VoIP carrier (they might have their logos on it), find those that are Cisco or Linksys branded. If that's the only one you have - just don't let in into the Internet.
Anyways, try experimenting!
2. You won't get speed any higher than 33.6k. You'd probably use a pair of the most common dial-up modems on both ends and even though they say they are 56K - that's for downloading. Pro stuff, like on ISP's used something technical to push it to that higher number, but it's quite complicated for an unexperienced user to set up and honestly I haven't researched that deep yet. As of now, from what I've read so far, you'd likely need whole another set of devices and modules to reach 56k, basically all from scratch.
3. (Skip this one if you want a simple solution and not a stupidity) If you are a phone company guy or worked there, have some skills in telephony and have a PBX - that's an ideal solution FOR A HUGE NETWORK if you ask me, however read thesis No.2. Honestly, I am not a phone engineer and only worked there briefly during IP-era (we are still transitioning from POTS in some places). But what I know for sure - we need a certain voltage, dial tone and configured circuitry to route atleast two phone lines together. I've said "atleast" for a reason - devices like "Phone Box offices" come in different sizes: from the tiniest 4-ports up to huge 24's or even bigger. It will be surely expensive, require additional modules if you're unlucky or want more ports for example, manuals also might be missing and again you won't get any higher than 33.6k without an ISP-grade gear. On the other hand - that would be unironically damn cool for a LAN party... if you have 20 friends... Oh, and good luck with those - they are hella expensive and painful to set up from what I've heard.
4. As I've said we need a middle-man in a face of the phone line provider to generate those crucial voltages and perform commutation. If your wallet is big enough or you still keep the remnants of the old past a.k.a. a real phone line... well... 2 phone lines, since you still need to host a server and a client somewhere. You can even wire two telco lines with the different number/provider at one house, but I doubt anyone would bother (Actually, I think some big american houses used the intercom systems that in some cases would use something similar to POTS across the different floors and rooms). For making a connection between, let's say, a home and a village - that's perfect. If you still own a line or able to afford it anyways (or wire own line across two rooms in your house, or across your room and the basement/roof/server room).
So, to help us - we need either:
I've used a Cisco 1861 Integrated Services Router, though it's only 4 ports in stock variant. I'm pretty sure they have more advanced solutions, you'd want something like Cisco 2821 with those wide slots to fit a bigger expansion in there, if you need more of course. That's actually a possible route to achieve 56k V.92 speeds using T1 cards, but that's quite another topic.
Here I would say that you can get a 2 or 4-port VIC card for it (Model: VIC-2FXS or VIC-4FXS/DID), but uh, well, 1861 is not a great solution - it clearly says that they are not supported. So, look for more advanced Cisco gear!
(1861 source reference)
Here's a visual reference for 2821 from the Cisco website. This guy supports way more expansions than mine does and I bet it has more power to work with.
CathodeRayDude
also has some videos about the telephony, though they might not get too deep into setting up and reviewing each device in detail, but even the SPA122 guide might help you alot, check out his 1-hour essay on the phone stuff - I really liked it.
5. You can input any dialing number in settings: 7075559080 or 120... etc I didn't really understand why bogus numbers for such setups were that long when you could just speed it up with 3-digit (or technically even to 1-digit) long, but I get it now - it's for realism!
6. After few retries I have managed to do a dial-up connection on SPA122, can't say it sucked too much, but it's still imperfect. It has just came to my mind that you can selfhost a SIP server (or get some free cloud solutions with minimum features) and just yank another one of those in the other room, so you'd have 4 clients which you can dial thru own Ethernet connection. But yeah, server may need some configuration for better signal quality... I guess? I am just speculating on that. So, back to SPA122, set "Jitter Level" to LOW and disable its self adjustment, should be to the right. That's still an experimental variant of doing dial-up which does work, but I'd prefer a more robust method without any digital interferences.
7. You may also do a Bluetooth Dial-Up Networking (DUN) connection, for stuff like old Windows Mobile PDA's, maybe other similar/older/newer devices. Though it will need some research, since I'm not really sure how to set it up and etc, maybe it's as easy as clicking two buttons and I'm just lazy (I don't have a Bluetooth adapter to test it either). Its specsheet says you can do speeds up to 128k and optionally for even higher ones! It is obviously great, but maybe it's only limited to the newest releases, but if 56k works - that would be great, though obviously tied to Bluetooth-capable devices or would require a USB-adapter if you want to host it on an old desktop machine or a server without built-in Bluetooth. Same thing likely goes to IrDA (infrared) connections.
(It actually does exist and works, and yes - it requires IrDA-capable devices). Source: vintage2000.org
8. You may also connect two dial-up modems directly and specify the lack of dialtone using some AT command to achieve higher speeds, as Gravis mentioned in his article, but I agree with him - high speeds are not really needed for a dial-up, that's not what you need. It may add some reliability as opposed to landlines, but besides pure speculations, as I've said you won't get any higher than your modem can push.
9. A thing called "Modem over IP (MoIP)" a.k.a. "ITU-T V.150" exists, but all I have found is a company Vocal.com which seems to have implemented this standard in their MoNet MoIP gateway. I've sent an e-mail to them requesting some brochures, but they don't really want to disclose any information beforehand and I don't really wanna join a web-meeting with them neither do I actually want to buy it.
From what I understood from their website is that you let your dial-up devices into the internet using their gateways. I'm not sure if you would use their "terminal server" or make (host) one yourself since you are a business too, but I can see that they could work in a similar fashion like Cisco/Linksys VoIP ATA's work without all the VoIP crap that had worsened our dial-up signal earlier and their article does indeed say they're using the same SIP protocol, except they have isolated "real-time processing [...] making it highly resistant to [...] network delays and packet loss". You can read more on the link below, if you're interested, however that's not an advertisement.
10. Oh hey there! AOL has announced the sunset of their Dial-up plan marked on 30th September of 2025 and atleast one good video about home-modeming has been published on YouTube! (It mentions CathodeRayDude too and a PBX that I was looking at before, heh).
Here's the link
- the author plays multiplayer Doom thru Linksys SPA2102-R (same model basically), and also check out
clabretro
- he has lots of other networking stuff there! I don't really recall whether I've used Cisco SPA122 or Cisco 1861 for my video, though it worked anyways.
11. I have not tested this, but more advanced users might try and look at self-hosted PBX solutions. It will not help eliminating the VoIP audio compressing part, but since it uses SIP something could be possibly made out of it, as the commercial MoNet MoIP gateway did.
This extremely simple and easy configuration will let you "just use" the telephony and it literally does nothing else. It will likely work on other Cisco devices that utilize the same voice module, but more advanced models use different "modem" modules and thus operate quite differenly, but they should be easy to setup too.
To recap: I'm using Cisco 1861 ISR Router with one VIC-2FXS Voice module.
Setting up:
At this point you should have every wire connected, devices turned on and you already need to know the basic Cisco command line knowledge.
Navigate to your console and perform these commands:
dial-peer voice 100 pots destination-pattern 1111 port 0/0
• 100 - is just an internal ID, so it doesn't really affect anything besides config.
• pots - is a marker that we are utilizing a Plain-Old Telephone System (POTS), you can alternatively use "voip", but yk we ain't dealing with it today.
• 1111 - is a phone number for that specific port, when someone calls it from outside - it will ring in here.
• 0/0 - is a port number, depends on a layout it might be either a built-in one or as a module and is written on it, a number on the right always begins with a zero.
Theoretically you can also set dial-peer mode to "data" instead of "voice", though as my brief googling reports it may be for ISDN... Might be a teaser for another post? Hmm. Dial-up requires slightly more powerful gear or perhaps some WICs that I doubt exist for this poor device. (As previously mentioned, they do not exist for this device.)
Now repeat this with as many ports you want to use, with as many IDs and destination-patterns as many ports you have free, so they would be different from each other.
Aaaaaand.... It's pretty much done! Type "wr" to save your config and you're good to go.
With such very basic configuration I could reach up to 33.6k Speed (which is the maximum that home-grade modems can upload at).
Since I have not tried them myself due to lack of required hardware, I cannot blindly post the guide straight up here, however I would happily recommend this video made by "clabretro".
I will add more info here as soon after I try it myself, with the credits kept respectfully, of course.
Edit: Wow! Clabretro coincidentally found out about that machine too and made a video about it! Check it out.
Edit 1 (Aug. 15, 25): added some pictures
Edit 2 (Sept.5, 25): fixed paragraph 5 - you do need a bogus number, but it may be any length you wish. made some explanations a bit clearer
Edit 3 (Jan. 6, 26): added and fixed some info
Edit 4 (Mar. 21, 26): added new clabretro's video'
this is an outro
