Another Electromagnetic Field has occurred! This was the third year we’ve ran a site-wide Plain Old Telephone Service (POTS) network at EMF, marking 6 years in the business!

Things started off with an attempt to pack the van as neatly and securely as possible:

A neatly packed van

It didn't look quite so neat after the 100 mile journey

Once we got to site the weather was much more favourable compared to 2024, so we were able to get all the gear into the Datenklos and even have a fully operational public phone outside ECHQ village by Monday evening. In 2022 we were still trying to get things working on the Thursday, so this is a huge improvement!

A public phone outside ECHQ village

For the first time ever we had almost zero issues with the core POTS functionality. All the Voice Gateways (or ATAs) had been pre-configured prior to arriving on-site, so we just connected them up and they came online - No attempting to run ansible from a camping chair! They also seemed to cope with the ~50°C temperatures inside the Datenklos, although the only temperature metric they expose is “OK” …

In previous years we’ve operated our own SIP proxy to manage re-writing the underlying temporary number without having to update the configuration on the physical device, but this year we’ve infiltrated worked more closely with the EMF Phones Team so the number re-writing is handled natively within the core SIP platform. This makes things less fragile, improves visibility for troubleshooting and makes for a better user experience.

We seem to have had more support requests compared to previous years, with most of them identified as “Layer 1” issues with cabling and adapters. Someone has suggested putting a cable testing machine somewhere publicly accessible which is an excellent idea, so we’ll try and make that happen next time. We’ll also try to improve our documentation and support.

The public phones continued to be incredibly popular with approximately 12 of them dotted around the site. A couple of them experienced issues but they were either repaired or swapped out fairly promptly. We’d love to see more public phones next time, particularly more unusual models, so if you can get your hands on one, please bring it! It just needs to be weatherproof and capable of mounting on a ~48mm scaffolding pole, or freestanding. If you want to make life easier we’d also suggest wiring it so you can just hook it up with an Ethernet cable.

Someone using a public phone (Posted with their permission)

Regrettably we didn’t manage to get a fax machine in the bar this year, as we managed bring not one, but two faulty fax machines. We made an attempt to troubleshoot one which involved a trip to a neighbouring Datenklo but it was unsuccessful. Apologies to anyone that got woken up by the sound of an engineer dropping a fax machine at 2am…

The Dial Up internet also worked, with a handful of users connecting and surfing the world wide web at (almost) 56Kb/s! We’d love for more attendees to experience the internet as it was at the turn of the millennium, so perhaps at a future event someone could stick a Windows XP machine + modem in the arcade or bar?

54.6K Dial Up!

Charlie from GCHQ.net operated the VDSL side of things, with a couple of ISPs “wholesaling” their own services over the top. Next year will try to expand our coverage area so more people can join the fun.

87Mb/s Down, 38Mb/s Up VDSL!

Unfortunately we ran out of time to get GPON going - it’s now an EMF tradition that we announce a new service but don’t deliver it until the following year. So perhaps 2028 will be the year of Fibre-To-The-Tent (FTTT)

Next time we’ll attempt to be a bit more organised and make sure things are “plug and play” to minimise having to fiddle with things on site.

Stats

☎️ 164 active POTS lines - 54% more than 2024
📠 714 Faxes
🖥️ 25 Modem Calls
📢 3995 calls made from Public Phones
📞 5337 calls made from POTS users

Acknowledgements

Many Thanks to:

• Orga
• Volunteers
• The Phones Team
• The Network Team
• The ECHQ villagers
• The HamSexies
• Jon - Engineering, Logistics, Administration, Hydration
• Charlie & Rewby - ISP Services
• lpbkdotnet - Getting the CuTEL “fun” services operational
• Mythic Beasts - Providing a virtual machine
• Everyone else that helped make EMF what it is.