Last Crossbar Telephone Switch (Central Office) In The 2022 PSTN (TESLA UK11 PBX) 

Thanks Phil, such a honor to hear from you. Yes, Im buying the switch and renting the place so I dont have to move it (for bow). Im looking to hooking it up to the C-NET, do you think you could help me with any advice how to become a part of CNET? Big up !

i hear that the best way to get connected to the C*NET is to get a dedicated asterisk server ( little desktop pc ) and hook it into the network from the asterisk server

@@suriva what @supercattelephone said. FreePBX is easy to get going. On a small PC. You’ll need FXS interfaces for the trunk lines. I’m doing something similar but with FXO ports to remote extensions over the internet to remote analogue telephones.

imagine caller line identification in 1980s....

thanks alot for your interest. we have 800 subscriber lines, 52 incoming DID trunks, 32 outgoing trunks, 8 bidirectional (long distance) trunks. there are 2 central markers, if I remember good 16 originating (local) registers, 8 incoming registers (from trunks) and 7 outgoing registers. as it is just an electromechanical switch it has not so common features as call waiting, intercept, forwarding, chain call, serial lines, trunk to trunk connection... hope I will bring more videos in the near future.

@@suriva thank you. I can't hardly wait to see more. Very interesting.

actually its government owned

@@suriva Do all the offices in the government building already have RJ-45 ethernet connections that already go to PoE (Power of Ethernet) switches? If so, a switch to a VOIP based system such as Cisco would be fairly quick and easy.

ahahah, ofc we have VoIP (asterisk) system for years, this is the last analog switch just because it servers remaining analog lines in 5 office buildings... there are hundereds of VoIP phones.

yes Im doing my best to save it all.. hope I could mange to rent the space so I dont have to remove it.... but its like hell of a dough yk

@@suriva renting the space while you get your plans together is good but obviously not a long term solution. One step at a time. You’ll figure it out.

oh, then Im sorry for the clickbait. actually its a bit more complicated. when it was built the incoming trunks were literraly the last 3 stages of the tandem office. nowadays its on a three-wire channel bank. you gotta ground "c" wire first, wait for "-" on "b" before sending dial pulses on "a". there are 8 incoming (dedicated) registers so it could be connected as a last selector and connector of a tandem step-by-step office... other curiosity is that this switch is governemnt owned and still operational as of today :D

@@suriva so the line is blurred. No pun intended. It’s a PABX that is integrated with the PSTN in a relatively sui generis manner. No apology necessary. Trunk line signalling is interesting for integration with asterisk.

isnt it amazing ? its still working btw... yes we got rid of most crossbars in mid to late 90s too

Thank you for your interest sir. Those are the little "cultural" diffrences.. basicly we had same switching systems like #1 and 355A step, #1 and #5 crossbar, crossbar and 4A tandems, even clones of all-relay switches like CX100, CX1000, later 1ESS/4ESS based topology like E10, DMS10/100, S12, ESWD in late 90s/early 00s up to softswitches and VoIP which I do not consider interesting anymore..

thanks for the reply. do you mean SL-100 which is DMS100s PBX version ? DMS100 is fairly large PSTN switch, both definitelly worth saving !

Yeah DMS100, we manage a few 200's too! Fairly large telco. I do hope that if they decom them they don't just scrap it, would be cool to get dibs on some of that hardware. I wouldn't know how to make it work but would be a cool novelty to at least setup the racks and stuff.

ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE--8qjfPgVAAs.html you wouldnt be the first one to have dms100 in a garage :)

@@redsquirrelftw you have to do this. If you can find the space you should do it. Live on a farm run it with solar. Haha. There are people out there that can help you get it going.

Im a big fan of connections museum however I will preserve this switch in fully working condition my self

wait wait wait... there were few Nortel SL1s in 80s and literally tons of Crossbars and even Steps back then. and yes there was a fully digital UE installed in the same time period (with size of a fridge) but was not EMP proof...

This isn't in the US. I think it's the Czech Republic.

@@batlin Oh sorry for getting that wrong!

@@GreatGizmo74 no worries, I wasn't too sure until I spotted a sign with "P. Modřany" -- Modřany is a suburb in Prague. Just like you I'd love to be able to save stuff like this since when it's all gone, it's gone for good.

good assumptions guys. actually I wont diclose the location since I want to save it. just to remind you that czechoslovak products were exported all over easter block.

They were still made at early 80's they were already "computerise" the switching matrix only where still mechanical. The switch evolution was mechanic "brain" and mechanic spatial "connexion matrix" electronic"brain" and mechanic spatial "connexion matrix" Computer "brain" and mechanic spatial "connexion matrix" Computer "brain" and analog electronic spatial "connexion matrix" Computer "brain" and digital "connexion matrix" The digital connexion matrix was designed in the early 70's since then the voice was digitized and send as packet just the same way it's done with Ethernet packets. but as you can imagine it cost a lot at the time; even if far more reliable (no more degradation in transmission) and huge multiplexing capability. So crossbars was still made even if already outdated they work well., just like you can still find DSL modem as you don't have fiber everywhere !

exactly. there were common program controlled analog switches in late 1960s (#1ESS) while "brute force motor operated mechanical" panel switches form 1930s were still in operation well into 1970s ... step-by-step COs like #1 or 355 invented in early 1900s were in operation into 2000s... EWSD, 1000 S12, DMS10, 100 from 1980s could be still found here and there today.... and human operators were absolutelly common even after 2000s its just matter of last decade that companies dont wnat you to speak with real people.... "if you want an operator to hang up on you press star now"

Many of the extensions are already migrated to VoIP. There are only 6 incoming trunks left and like 10 outgoing. Was filmed in the evening or on holidays, idk, I usually work late.

nah, its eastern block "copy", been produced since late 60' to mid. 80'

dobry den, jsme stale v provozu, postupna migrace na VOIP, ustrednu celou zachovam, snazim sa pronajmou prostory, kdyz ne, odsehuji jinde, muzu mit na Vas nejaky kontakt ?

Good catch. The CO is made in Czechoslovakia. Sorry I aint giving out the location before Im getting the ownership.

@@suriva Lidém kteří se snažejí zachránit takové ústředny od kovošrotu akorát fandím. Doufám že se vám podaří vykoupit a také doufám že jednou budu mít možnost se s tím zahrát.

Jak to dopadlo nakonec? Můžu přijít na exkurzi?

most of the phones are push button but set to dial pulse mode.. worst problem is the voltage 60V.. most of the "western" pohnes could not handle that :D

Hi Phil. The switch is still in service. If everything goes well Im gonna save it in full working condition. Nothing will get scrapped. Not gonna disclose any details for now but once its decomissioned I plan to make it accessible to public (either telephone-wise but physically too). Thanks for the care.

The switch is stil in operation. Im trying to save it. Once its decomissioned I plan to make it accesible (both telephonewise and phisically)

next episodes..

thanks. the owner is the government. its still operational. luckily I work at this place and I will do everything to save it in fully working condition... I wont disclose any further details now that could ruin my plans.

definitely not, as far as Im alive

nemam tuseni

the switch still in fully working condition. waiting for decomissioning. will try to make it available both telephonewise and physically.