 Thank you everyone so for those of you that don't know this year at EMF we've got pretty much a site-wide telephone network as it's traditional ish copper network or you could call it a plain old telephone system so we're gonna talk a bit about how that came about and the journey and what went wrong so a little bit about me I'm Matthew I've worked in telecoms sort of voiceover IP for 10 years that's everything from single phones in someone's house for like a small business to hundreds of phones and hundreds of offices around the world so I'm fascinated by communications not just phones but amateur radio networking pre-internet bbs stuff anything of that nature and when I'm not playing with phones I like to play with phones generally the more physical aspects so sort of restoration so this is some of my phones these are all in pretty bad shape when I got them they're old sort of 1940s GPO Bakelite phones so with a bit of elbow grease it's relatively easy to get them looking brand new just a lot of polishing and cleaning and and all the rest of it so before we go too far into it there is this isn't the first time someone has done a pots network at a hacker camp so I think shady tell one of the first they're sort of collective of people in the US that tend to run a telephone network another hacker camp called tour camp so their niche if you like is they do real telephony so they don't do IP or voiceover IP they just use T1 ISDN between all of the different sort of breakouts over the campsite there's also the chaos vermitzelung they started in 2015 as far as I know and they actually do field telephones so they do some of the chaos events in Germany and their their niche is a manual exchange so you pick up the phone and speak with an operator and then someone manually patches you in and then the sleepy who some of you will know on Twitter they ran a pots network in 2018 so they had a single gateway in their tent and ended up serving I think it was about 10 people in their location so that's the history and then we get to how it started so I've got a bunch of phones some of them are dotted around and the bakelite ones that you saw so I wanted to bring them to EMF to sort of connect up to the deck network so I started to look for analog telephone adapters of wise known as ATAs they basically convert like a traditional analog telephone to voiceover IP and specifically I was looking for one with pulse dialing because a lot of my phones use pulse dialing which rather than using DTMF where you press a button and it beeps it interrupts the line so you rotate the dial and then it opens and closes the line to signal the number so I found some Fred on a forum recommending some grand stream ATAs and I've got a couple of those and they they work really well they support pulse dialing but Cisco were also mentioned but I initially dismissed it so for those that you don't know Cisco is a huge sort of enterprise networking manufacturer or vendor they have voice products but they tend to well I was under the impression that it was all proprietary you had to use what's called Cisco call manager and I never really considered trying to do things with sort of open source voiceover IP products but I did have a small amount of Cisco gear lying around so the story goes is I was looking to get hold of sort of three switches to play with some spanning tree and as you do I was looking for listings ending soonest on ebay and this came up it was literally opening bid was 50 quid and no no one had bid on it so I bid 50 pounds and then sure enough I won and then had to figure out what I was going to do with a rack and half of end of life Cisco gear so the good news is within that rack of stuff there was a couple of things that were actually worth money so there was a power distribution unit that was worth 100 pounds and the racks themselves I think I've got about 50 pounds each for so I ended up coming out of it with some profit and a bunch of Cisco stuff lying around so I started to play with the Cisco stuff and kind of discovered that actually it mostly just does work they can speak pretty standard SIP and interact with other SIP things without too much effort so at that point I started wondering well maybe instead of just bringing my phones I could put a few of these around the site and other people could bring their phones so I started working out pricing and stuff I had a bunch of the 2811's which are a kind of smallish router but it was about 80 pounds each to upgrade them to a point where they could be used for telecoms and that would only get you 12 ports which is quite a lot of money for a lot of not many lines which is then somewhere it was possibly on reddit I discovered a Cisco vg224 which is the same form factor as the kind of big chunky Cisco routers but actually has 24 lines and at the time they were incredibly cheap I think they've gone up a bit now because I bought them all so yeah that was kind of when things started to develop and I started to think maybe maybe this could be like a thing so this is what those Cisco vg224's look like you'll notice they've got that weird connector on the side that's what's called an RJ21 which is a connector commonly used in sort of telecommunications you might also know it as a Centronics 50 pin I think it's used for SCSI but these cables were incredibly expensive they're sort of like 30 pounds each for a meter long so then it started to look less likely that it would be a thing but I put a tweet out on Twitter and a bunch of people replied to me and said I've got a bunch of them in my shed you can have them for a five for each and I managed to get holding them off various people for reasonable money so at that stage it started to look like you know this this this might actually happen so I started playing with the voice stuff and made some calls between them and then I went off on a tangent so quite early on I realized there's as much as I love phones people aren't going to be sitting in their tent phoning each other for hours at a time it needs to be something more interactive so I started wondering about things that you can run over the top of a phone line so the obvious ones are faxing modems and dial up internet so dial up a few people have been experimenting with this recently it seems to have reached a point where everyone's forgotten how bad it was and then have started to sort of dig out old modems and try to recreate it someone called Retrobytes on YouTube has a really good video made in the last six months where they kind of go through how it worked in a way that's easy to understand but they also make their own setup and go through how you can do it yourself but most of these solutions involve like a stack of modems, serial adapters, raspberry pies and what you end up with is like a huge pile of spaghetti which is probably okay at home but less helpful in a tent so I found a YouTube video from someone called Zeffy they had a Cisco based setup so Cisco had these modem cars have basically 30 modems all built into one box and it turns out in my huge pile of Cisco gear I had some of the bits that were needed so I managed to get a few bits off eBay and put something together so this is what that looks like this is a 3U Cisco 3845 and on your right are the modem cars so they've got modules with the modem chips on them so that'll get you 30 modems in a single box there's less cables and it includes the world's shortest ISDN link so that that red cable is ISDN and the reason it's plugged into itself is if you want to send calls over IP they have to hit the modem over ISDN that's just how it works so essentially you send a call to it over voice over IP it loops it back out to itself over that ISDN link and then back into itself and it's too stupid to realise that it's just looping around for itself there are some catches they are incredibly loud really power hungry I use kilowatts of power just testing all this stuff and there are some limitations so it's not the ideal system but it's what's available and they're fairly cheap so I've got all that working and then yeah as I said earlier it turns out dial up sucks all websites are so bloated now they've all got sort of five meg of java script even if you do wait web servers tend to time out now because they just close the connection after a minute and then there aren't really that many low bandwidth options available even a lot of like the mobile sites and stuff which are lower bandwidth still kind of assume that you've got a connection from this century so this is when I discovered prestel or view data so I'd literally never heard of prestel despite claiming to be a telecoms nerd but I had heard of the minitel system so these are video text or view data services they're very similar in kind of appearance and operation to teletext which you may have seen around the site on various TVs but it's done over a phone line so that gives you the added benefit that you can actually send data to the service so at the time you could do things like order cinema tickets and do online banking and various interactive services it was basically kind of the internet before the internet existed it runs at 1200 board down and 75 board up the idea is that no one would type faster than 75 board so that's fast enough but unfortunately it didn't take off in the UK really just due to high costs you had to pay like a quarterly subscription you had to pay for the phone line and you had to pay per minute to access it so it's just too expensive but fortunately someone called John Newcomb has made a modern cross-platform client and server called Telstar I highly recommend you check it out phone calls and calls routing between them but then you have to start thinking about how you're going to cover like a huge festival site with this stuff so fortunately power and internet are already provided and the dat and close are already dotted around the site which provide a waterproof home for the gateways to live in so for those of you that don't know a dat and close is basically a portaloo which is used to hide switches and power in because it's the cheapest way to get a plastic box into a field for a week a lot of the the cabling between the phones and the gateways themselves is done just with cat5 just because it's pre-terminated you can buy one on amazon and get it delivered next day and I really didn't want to be punching down cables and doing that kind of thing which would be the more traditional way of doing it so I made a bunch of breakout boards basically PCBs with a bunch of RJ45 connectors on just so you can walk a patch in and it's all self-serve and doesn't really rely on anyone doing anything and then these were put in buckets outside the dat and close so you might have seen a bucket or possibly kicked it or tripped over it and that's where all the patching happens so this is what that looks like that is a dat and close before it's even got a network switching this was super early on sort of the Tuesday last week but yeah it's a portaloo that metal box on the on the toilet seat is a voice gateway and then outside you've got the bucket and then the photo shows the breakout board so that big chunky connector at the top is the RJ21 fortunately you can get those connectors fairly cheaply from aliexpress like everything else and then you've got the lines broken out below so each of those voice gateways has 24 lines that's split into 12 individual lines and then three ports of four lines so if you want to take four lines to a village or josh's campervan or anywhere you like you can just run an ethernet cable with four lines on it and then we get to the back end so obviously the all the voice gateways need something to talk to to root calls between them and to root calls to the the deck phone and the various service systems on site so it's all built from scratch using open source software there are some products sort of like free pbx and stuff where you get like a telecom server in a box and you just install it the downside is they're not particularly easy to customize and we had some kind of unique situations that we had to count for so I mostly wrote it from scratch everything runs in plain docker mostly just because it's nice and easy and it's easy to sort of redeploy stuff and move it around and all the voice gateways send calls to a central chameleon based cip proxy so chameleon is a cip proxy and it's it's incredibly lightweight and efficient so you might have heard of asterisk asterisk does things like media so IVRs dtmf faxing conference calls voicemail all that good stuff but as a result it's kind of more inefficient i start to use chameleon in the middle and then there is a python and redis based api which is used for sort of routing decisions there is an asterisk box there it does voice announcements so it tries to replicate some of the bt announcements like this number is unavailable blah blah blah there is some monitoring it's Prometheus and Grafana with smoke ping I didn't invest a huge amount of time in that and I probably should have done but it mostly works if one of them switches off my phone vibrates so that's that's good enough I think and there is a bit of free radius in there so there's cip proxy generates call records and they're stored in free radius just just to generate statistics I don't really care so much who's calling who and all that data is going to get deleted but it's just good to know how many how many phones are out there and how many calls and how many minutes and that kind of stuff so successes it it mostly worked was good start there's there's 24 gateways deployed around the site there's mostly in decays but there are some there's one in the bar that we're going to set up later there's 50 unique users so that's that's 50 people have bought phones or used the phones dotted around the site there's been 500 calls that's both between different pots phones between pots and decks and to some of the the services that other people have set up five hours worth of calls there's been 100 plus faxes there might actually be more because I don't necessarily know who's got a fax machine and he hasn't but from the fax machines that I know of there's been over 100 faxes sent um someone's also set up a cat fax hotline I highly recommend you ring it it's a real person it's not even automated they're up they're up in your hack space so yeah gives them a call perhaps not at four o'clock in the morning because it is quite literally a telephone in someone's tent and fax to Twitter has proven to be incredibly popular so if you go on Twitter and look at emf facsimile if you send a fax to the the number tweet it will appear on Twitter we're hopefully going to set one of those up in the bar later today and people have bought like a whole load of cool things I've got some pictures I'll show you shortly um so I was going to call this slide failures but the whole thing has been a bit of learning experience and I've kind of drawn the conclusion that there aren't really sort of failures at EMF it's more like missed goals stuff that you can do next time um and to be fair if everyone did everything they wanted to achieve the first time around then there would be no need to have a second second festival so yeah these are these are missed goals rather than failures so things ran dramatically behind schedule I kind of totally underestimated the logistics involved it's quite easy to sit at home in front of the computer playing the software and totally missed the fact that you've got to walk around a huge site and and put stuff in in portals and stuff so some phones were distributed around the site and didn't work for various reasons bits were left at home one of them is physically broken um dial up dial up internet hasn't happened yet but hopefully we're going to do that later today and some installations haven't made it to the bars but again we're going to try sort that out later today but the good news was people still loved it even even when everything was broken everything was on fire people were still coming up to me and telling me how amazing it was and I kind of say well yeah but but none of it works and they'd be like well the fact that you've even attempted it is amazing um so I've now got some pro tips I wasn't really planning on this slide but it's kind of been a bit of a journey so I thought I'd include it um so if if you're planning to do some crazy huge project to emf I highly recommend it um just just do it and people are awesome so I had so many offers of help and people were saying thanks and like positive feedback um so yeah the next one help help people help you so a big problem I had is basically the whole setup everything existed in my head so there were there were multiple people asking how they could help and there was just no real way that I could easily tell them what I needed doing so if you're planning a big project I highly recommend in advance before you get here making a plan for people to help you so that could be sort of printed instructions if someone needs to go put something in a bar put it all in one box with everything they need so you can just give them that one box and tell them to do that thing um so I think that's a huge thing I was kind of overwhelmed by the amount of people that wanted to help but so you yeah if I recommend making that as easy as possible um next one do much as much as possible before you arrive so some stuff I had tested like six months ago but hadn't touched since and just assumed everything would be fine um and it it was not fine um to try and do as much as you can before you get here I found that you know sitting in an office chair in front of two screens doing software stuff at home with a coffee machine and stuff is all very well and nice and easy but then when you're in a tent in like a folding camping chair and it's raining outside it gets considerably more difficult um prioritise things and expect things to not get finished I think it happens to just about everyone at EMF that tries to put together some big projects I think you should just expect it and you should have like nice to haves and and prioritise things and not not get too stressed if something doesn't happen um and then the final thing is just enjoy it um there's no point kind of killing yourself just to try and finish something if it's if it's not looking like it's going to happen just just just don't do it there's always next time um so now we get to the pictures um so like I said people have bought some really cool stuff um some of it sort of dotted around the campsites some people have come up to their amateur radio village to kind of show it off um so this is a Epson PX8 I don't know very little about it but it's a very early laptop with an LCD display it's got an acoustic coupler and then next to it is a 746 phone so that's kind of 70s we didn't manage to get it working unfortunately yesterday but fingers crossed we might be able to do something with it today um so I've got an acoustic coupler at home I didn't bring it because it needs fixing but I would love to see more acoustic couplers next time because they're amazing someone also bought a bat phone it's literally the batmobile as a phone which I was super impressed with and someone bought an amstrad e-mailer this is a posh one it's an e3 which has a keyboard and a games controller apparently um so I would love to see some amstrad e-mailers working that I have read information that they apparently brick themselves if you plug them into a phone network and they can't phone home so it'd be good if someone could find like some kind of work around or fix for that because it would be cool if everyone could have an amstrad e-mailer in their tent uh another village another village bought a vintage bt fax machine a proper thermal one with a roll uh and a very yellowed bt phone um and they actually challenged us to a game of noughts and crosses and hangman uh which was awesome it was like the the slowest longest game of noughts and crosses you've ever seen and someone bought a apple newton so it's like a pda with a little plug-in modem they were sending faxes to twitter from that which was incredible I think a lot of this stuff people haven't either bought it and have never used it or um they've had it since the 80s and have not used it for 30 years so people were loving finding an excuse to actually bring it out and use it again um so we are recruiting um so this year was about getting things kind of bootstrapped and increasing visibility so more people know about it no more people know what to expect next time and what to bring um so we need more people to do more things uh we've got all roles available from software to to logistics to graphics design if you if you want to get involved um the more the merrier really uh you can find the twitter it's q telecom or or grab me around the site if you want to get involved because it'd be good to do some more cool stuff um speaking with people already the there is hopefully going to be bigger and better things next year there's been sort of offers of equipment and things which are all much appreciated and should be able to enable us to do more cool things next year and uh yeah we'll be back so fingers crossed if we're invited back we'll be back in 2024 and do more more cool telecoms things um and that is pretty much the conclusion at the talk i just wanted to say like a big thank you to everyone that's helped either on site with putting phones up and laying cable uh a bunch of people on various IRC channels and forums that have all helped with like how to get this ancient Cisco gear working um and yeah that's me so thank you very much if anyone has any questions um i will be loitering in the bar which is next door uh and then we'll probably head back to the amateur radio village so if you want to come send the fax to twitter or check out the view data system on a bbc micro come stop by and we can show you some cool stuff thank you very much