T-Carrier Preview
Added 2026-01-13 01:35:42 +0000 UTCHere's a preview of the progress I've made so far on a video about T-Carrier (i.e. T1 and T3). I'll be covering T3 hands on in the video eventually but I've had a ton of travel (and more to come) so progress has been slow.
So far the history of T-Carrier and part of a technical explanation of T1 is done, let me know if I've made any mistakes and I'll try to re-shoot those for the final video!
Comments
I'll touch very briefly on the existence of ISDN PRI but that'll be in future dedicated videos! I've heard good things about those other books, they're actually in my Amazon cart already haha
clabretro
2026-01-20 02:48:38 +0000 UTCThanks for the thoughtful response! Yeah the "documentary" style isn't something I'm used to, hard to make it natural. I'll have a lot of messing around with the actual equipment to get T3 working in the final video. I agree about "saying something wrong," the telephony folks seem to be particularly sensitive to it 😂. I'll briefly touch on framing, robbed bits, and that E1/3 exist, but I'll have to save a deeper dive for another time I think. I'll at a very minimum have all my sources for the various articles I read cited in the description as well. I do need to get back to that crestron gear someday and actually try the wild software (I've heard it's quite the experience).
clabretro
2026-01-20 02:48:01 +0000 UTCI'd always heard Unix was partly invented to help with the massive amount of typesetting work happening at AT&T. Now I know why! I used to assume T1/T3 lines were something special that had to be run for new customers, which made no sense. Now I understand they just used existing lines. [/epiphany]
Mac Folklore Radio
2026-01-19 06:11:01 +0000 UTCThis is just my opinion, so please take with a grain of salt. The first part seems a little rushed. Technically its awesome but its not like your other videos where you are working out as you go along and we are along on the adventure with you. (not sure how you can do that with a history lesson). You have got the right info that you need to present, but just seems like your in a hurry to get the video out. Something that I really like about your channel is that its easy to watch and not lecture based. I don't know your process either or how you cut these into the finally product so this maybe how you do things. The bit after the segway to how it works (After AT&T screen flashes up). After that, you're relaxed, presenting as normal, before that you sounded like you were late for an appointment and had to record the video before you go. FYI Human hear can hear 20 to 20, 20hz to 20Khz maybe explain a little more why Nyquist came up with why encoding voice and you need 8khz. Dont forget call signalling, robbed bits (CAS) or the dedicated channel, (CSS) and how E carrier is so much better for CSS. Are you going to go into the call signalling methods? maybe a bit too deep. And don't forget to credit and put the sources for your material. Overall mate, its really good. I'm keen to see the full finished product. Your doing very well getting all your info too, not an easy task as it is history now. I'm going to buy that book now too. This part is just a rant as I feel your worried about saying what you think online which is just wrong. Something which really really annoys me with social media/internet, its killing imagination by ppl needing to obsessively fact check every bloody thing.. You're allowed to have your own opinion/belief. example. My opinion of how a network cable functions is; At the sub atomic layer there is this long line of tiny tiny little people standing next to each for miles and miles, they play Chinese whispers saying 1 or 0 to each other and thats how bits flow in a cable. In full duplex there is 2 long lines of tiny tiny little ppl. that's how data is transmitted. Technically this is complete BS. but that's how I think and that's ok. You can have your opinion and still be wrong technically. I guess As long as you say I imagine this or My opinion is blah, your should be covered and anyone else can go F off. Sorry for the long write up, but I hope it helps, I did watch it a few times. You obviously have high expectations for this one and I think you are meeting them. You could take a break and release another lower quick filler vid while you work on this too. That's if you can do that sort of thing. you have plenty of material. Calestron follow up and the software that backs it up??
Fronzel Neekburm
2026-01-16 02:34:59 +0000 UTCNot sure if you are already planning to, but I would mention how the T-1 compares with ISDN PRI since they are similar and people have used the terminology interchangeably (incorrectly) in my experience. I had that T1 book! Really excellent. That and Ethernet: The Definitive Guide and Network Warrior, 2nd Edition are some staples you should have for all of these adventures. Especially Network Warrior.
Michael Dragone
2026-01-13 16:50:06 +0000 UTC😂
clabretro
2026-01-13 16:03:59 +0000 UTCDefinitely, I'll acknowledge that there are differences for E1/3. I might even have an E3 port adapter to show.
clabretro
2026-01-13 16:03:37 +0000 UTCThank you, I did!
clabretro
2026-01-13 16:03:00 +0000 UTCHope you had a good time in Europe! (other than the sickness)
Martin Paulsen
2026-01-13 14:24:15 +0000 UTCI think it would be interesting to point out the european difference i.e E1 is faster than T1 but E3 is slower than T3.
Jon Creasey
2026-01-13 13:02:54 +0000 UTCyep, I'm the devil for sure, but wouldn't you trade your soul for being able to talk to people in a different location?
t
2026-01-13 06:52:49 +0000 UTCthat's a good call, I think the "samples per second" language is much easier to follow. I'll use that whenever I talk about it in the next section
clabretro
2026-01-13 03:19:29 +0000 UTCWould love to see more of that AT&T video included, love those old school explanation videos. Overall your explanation seems to be right, I would say 8,000 samples per second instead of 8 kHz just to be more clear.
Jeremy Whaling
2026-01-13 03:13:08 +0000 UTCThanks! You're right, it's 10,800 per coaxial pair but is indeed 108,000 per 11 pairs in one large cable bundle. Got it from the second page here: https://www.telephonecollectors.info/index.php/browse/document-repository/catalogs-manuals/bell-system-we/1794-weco-l5-carrier-tl/file
clabretro
2026-01-13 03:09:04 +0000 UTCWhen you mentioned L5 carrier, you said 100,800. I think you meant to say 10,800. I'm no expert at T-carrier so I'll leave the examples and knowledge to someone more qualified. BTW I love the O'Reily book nod. I still have a few of mine. I miss them. Best book covers ever. Great premise for the video. Seems to be logically laid out. No need to get into the weeds or apologize about not including every little explanation (that would take multiple videos which isn't your objective here). Excited to see the finished product.
Joshua Zukerman
2026-01-13 03:04:28 +0000 UTCThat bell system logo brings back some memories of payphones I used as a kid.
Will G.
2026-01-13 02:37:19 +0000 UTC
