Getting closer. The dialin line that comes out of the 56K modem bank actually runs over the digital side, you won't need a POTS line simulator, you'll need a FXS line card. Probably the simplest (least hardware, that is) way to accomplish what you want is to drop a dual T1 card in an Asterisk box and plug in an ADIT 600 or similar. You may be able to accomplish it with a Cisco ISR that supports voice cards like the Cisco 2800, too. The most common carrier-grade hardware for running 56K is going to be a rack mountable unit with 23/24/46/48 digital modems in it, like the US Robotics Total Control. They take one or more T1s in the back for the "voice" lines, and various things for the Internet end (V.35 sync serial, ATM, Ethernet, etc). We may actually still have a spare kicking around, I'll check and see if it's available if you're actually interested in running such a monster. If you really want to run 56K you are going to need to "simulate" most of the phone company. "Simulate" in quotes because you'll be actually implementing a tiny central office. There will be nontrivial dialplan programming/configuration required, no matter what you go with. Other folks have had this going though -- TangentDelta had such a setup running when he worked here, and I think ShadyTel has done it in recent memory. If you're going to be at VCF MW, there's going to be a pretty extensive telecom setup that would likely answer most of your questions. Thanks, Jonathan On Monday, July 1st, 2024 at 20:56, John Heritage via vcf-midatlantic <vcf-midatlantic@lists.vcfed.org> wrote:
Ok I've been thinking about this a bit more. Is all of the equipment required as follows:
"iSP" / receiver end - a modem capable of interfacing digitally and talking to analog modems. (I.e. USR Courier I-modem).
An ISDN simulator to create the digital connection.
A telephone line simulator - to provide dial tone and handle call routing between the ISDN simulator and your analog modem.
Of course a computer on the "dial end" with a terminal program, and either ISP software or a BBS application, or terminal program with auto answer capability at a minimum on the "ISP side".
The digital side avoids an extra DA conversion which is what allows the 56K "download" from the 'callers' perspective.
Do I have it now?
Thanks!
On Mon, Jul 1, 2024, 6:18 PM John Heritage john.heritage@gmail.com wrote:
Thanks Dean, Gregg, and others -- that's what I wanted to confirm, to make sure I understood there was another ("digital connection") component required to enable "56K", and that there wasn't some simple method like using two Courier I-Modems. I assume a line simulator alone won't do this since the reddit poster used: a Dial-up server, an ISDN simulator, a T/A ISDN terminal, and an ATA to make it work.
I got out of the BBS scene a little early in 1994 (visit from Microsoft and Novell), so I was familiar with HST, V.34, and compression methods, but when I eventually got back into computers "with the internet", I never took the time to learn how 56K really worked before switching to cable modem.
Is anyone aware of any "hacks" that can simulate ISDN / DS0 stuff using a Raspberry Pi or similar? or is it pretty much - go source old hardware that does this if you want 56K for a home lab test environment? I can't seem to find any via searching.
Thanks! John
On Mon, Jul 1, 2024 at 10:55 AM Dean Notarnicola dnotarnicola@gmail.com wrote:
56K modems were never meant to direct connect to each other when both ends were terminated on analog POTS lines. I remember having to explain this to people back in the day that wanted to connect house to house or connect branch offices faster than 33.6K. Service providers had dialup Points of Presence that had incoming digital connections and could negotiate 56K. The upstream connection was established at 53K to 56K (under the right conditions) and the downstream connection back to the user was 33.6K max (analog.)
David was right and you will definitely need to simulate a digital connection to get 56K.
On Sun, Jun 30, 2024 at 7:12 PM John Heritage via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
Hi Gregg!
Right now they're just direct connected via q phone cable. No phone line simulator was required for the 33.6kbps speed I'm getting. (Ignore dial done on one modem works while the other answers via ATA).
I'm just trying to understand all that is required to enable 56K capability.. Thanks!
On Sun, Jun 30, 2024, 6:40 PM Gregg Levine gregg.drwho8@gmail.com wrote:
Hello! How are you connecting them together? You'd need two phones and and a phone-line simulator, or two phones and an ATA, see here for advice, https://gekk.info/articles/ata-config.html Finding them things is easy, oddly enough the one I used was from our free pile from a recent (not this year) swap meet.
And the dinos are dancing in the light rain. ----- Gregg C Levine gregg.drwho8@gmail.com "This signature fought the Time Wars, time and again."
On Sun, Jun 30, 2024 at 4:09 PM David Ryskalczyk via vcf-midatlantic vcf-midatlantic@lists.vcfed.org wrote:
I found a few other Reddit posts with details but don’t have them immediately on hand. Pretty much yes, you’ll need digital phone line / ISDN hardware.
David
On Jun 30, 2024, at 4:04 PM, John Heritage john.heritage@gmail.com wrote:
Thanks!
I was reading this reddit thread earlier, and was having a little trouble following, so I wrote below to verify what I took away.
(Thanks again)
On Sun, Jun 30, 2024 at 15:43 David Ryskalczyk d235j.1@gmail.com wrote:
> There is a good writeup of what you’ll be facing here:
https://old.reddit.com/r/retrobattlestations/comments/t5m6od/56k_upgrade_to_...
> David > > On Jun 30, 2024, at 3:01 PM, John Heritage via vcf-midatlantic < > vcf-midatlantic@lists.vcfed.org> wrote: > > Hi folks! > > I'm messing around with a bunch of modems at home, and would like to > know > what's required to set up one system to receive 56K calls from > another > system. > > I'm able to get 33.6kbps bi-directionally (or 31.2K) with just a > phone > line > between the two modems, and using ATX1D and ATA commands. > > I think to get 56K I require some equipment to simulate a digital > connection, and I'm also not sure if a 56K analog modem can even > receive > 56K calls. Is this true? > > Modems I have on hand: > - a USRobotics Courier I-Modem > - 2 x USRobotics V.Everything, and a USRobotics 56K/X2 Sportster > external > modem > > I am also unable to get the I-Modem to connect to any of the analog > modems, > and although it does have the protocols to support analog, it seems > like > it's expecting a BRI / ISDN connection to allow that connection. > Is > this > true? > > If the above are true - what's the minimum / cheapest solution for > being > able to at least establish a V.90 connection given the equipment I > have > already? > > Thanks for your help! > John