Harald "LaF0rge" Welte: Deployment of future community TDMoIP hub

I've mentioned some of my various retronetworking projects in some past blog posts. One of those projects is Osmocom Community TDM over IP (OCTOI). During the past 5 or so months, we have been using a number of GPS-synchronized open source icE1usb interconnected by a new, efficient but strill transparent TDMoIP protocol in order to run a distributed TDM/PDH network. This network is currently only used to provide ISDN services to retronetworking enthusiasts, but other uses like frame relay have also been validated.

So far, the central hub of this OCTOI network has been operating in the basement of my home, behind a consumer-grade DOCSIS cable modem connection....

Deployment of future community TDMoIP hub

I've mentioned some of my various retronetworking projects in some past blog posts. One of those projects is Osmocom Community TDM over IP (OCTOI). During the past 5 or so months, we have been using a number of GPS-synchronized open source icE1usb interconnected by a new, efficient but strill transparent TDMoIP protocol in order to run a distributed TDM/PDH network. This network is currently only used to provide ISDN services to retronetworking enthusiasts, but other uses like frame relay have also been validated.

So far, the central hub of this OCTOI network has been operating in the basement of my home, behind a consumer-grade DOCSIS cable modem connection....

Паттерн внедрение зависимостей в .NET nanoFramework для микроконтроллеров

Сегодня сломаем привычный мир инженеров и разработчиков встраиваемых систем на микроконтроллерах. В .NET существует замечательный паттерн программирования, как внедрение зависимостей (Dependency injection, DI). Суть паттерна заключается в предоставление механизма, который позволяет сделать взаимодействующие в приложение объекты слабосвязанными. Эти объекты будут связаны между собой через абстракции, например, через интерфейсы, что делает всю систему более гибкой, более адаптируемой и расширяемой. Но когда ведется разработка для микроконтроллеров, все зависимости обычно жестко завязаны на используемых устройствах, и замена датчика иногда приводит к существенному переписыванию программного кода. Напишем приложение на .NET nanoFramework для микроконтроллера ESP32, используя паттерн DI с возможностью легкой замены датчиков и LCD...

Harald "LaF0rge" Welte: Clock sync trouble with Digium cards and timing cables

If you have ever worked with Digium (now part of Sangoma) digital telephony interface cards such as the TE110/410/420/820 (single to octal E1/T1/J1 PRI cards), you will probably have seen that they always have a timing connector, where the timing information can be passed from one card to another.

In PDH/ISDN (or even SDH) networks, it is very important to have a synchronized clock across the network. If the clocks are drifting, there will be underruns or overruns, with associated phase jumps that are particularly dangerous when analog modem calls are transported.

In traditional ISDN use cases, the clock is always provided by the network operator, and any customer/user...

Harald "LaF0rge" Welte: Progress on the ITU-T V5 access network front

Almost one year after my post regarding first steps towards a V5 implementation, some friends and I were finally able to visit Wobcom, a small German city carrier and pick up a lot of decommissioned POTS/ISDN/PDH/SDH equipment, primarily V5 access networks.

This means that a number of retronetworking enthusiasts now have a chance to play with Siemens Fastlink, Nokia EKSOS and DeTeWe ALIAN access networks/multiplexers.

My primary interest is in Nokia EKSOS, which looks like an rather easy, low-complexity target. As one of the first steps, I took PCB photographs of the various modules/cards in the shelf, take note of the main chip designations and started to search for the...

Harald "LaF0rge" Welte: Retronetworking at VCFB 2022

I'm happy to announce active participation at the Vintage Computing Festival Berlin 2022 in two ways:

Running a retronetworking exhibit on Modem and ISDN dial-up

Giving a talk on the Osmocom Community TDMoIP netwokr

The exhibit will be similar to the exhibit at the retrocomputing village of the last CCC congress (36C3): A digital telephony network with ISDN BRI and POTS lines providing services to a number of laptops with Modems and ISDN terminal adapters.

We plan to demo the following things: * analog modem and ISDN dial-up into BBSs ** text / ANSI interfaces via Telix, Telemate, Terminate ** RIPterm graphical interfaces * analog modem and ISDN dial-up IP/internet * ISDN video...

Retronetworking at VCFB 2022

I'm happy to announce active participation at the Vintage Computing Festival Berlin 2022 in two ways:

Running a retronetworking exhibit on Modem and ISDN dial-up

Giving a talk on the Osmocom Community TDMoIP netwokr

The exhibit will be similar to the exhibit at the retrocomputing village of the last CCC congress (36C3): A digital telephony network with ISDN BRI and POTS lines providing services to a number of laptops with Modems and ISDN terminal adapters.

We plan to demo the following things: * analog modem and ISDN dial-up into BBSs ** text / ANSI interfaces via Telix, Telemate, Terminate ** RIPterm graphical interfaces * analog modem and ISDN dial-up IP/internet * ISDN video...

Progress on the ITU-T V5 access network front

Almost one year after my post regarding first steps towards a V5 implementation, some friends and I were finally able to visit Wobcom, a small German city carrier and pick up a lot of decommissioned POTS/ISDN/PDH/SDH equipment, primarily V5 access networks.

This means that a number of retronetworking enthusiasts now have a chance to play with Siemens Fastlink, Nokia EKSOS and DeTeWe ALIAN access networks/multiplexers.

My primary interest is in Nokia EKSOS, which looks like an rather easy, low-complexity target. As one of the first steps, I took PCB photographs of the various modules/cards in the shelf, take note of the main chip designations and started to search for the...

Clock sync trouble with Digium cards and timing cables

If you have ever worked with Digium (now part of Sangoma) digital telephony interface cards such as the TE110/410/420/820 (single to octal E1/T1/J1 PRI cards), you will probably have seen that they always have a timing connector, where the timing information can be passed from one card to another.

In PDH/ISDN (or even SDH) networks, it is very important to have a synchronized clock across the network. If the clocks are drifting, there will be underruns or overruns, with associated phase jumps that are particularly dangerous when analog modem calls are transported.

In traditional ISDN use cases, the clock is always provided by the network operator, and any customer/user...

Одноплатник MangoPi MQ-Quad в форм-факторе Raspberry Pi Zero W всего за $26.70

Стартап Widora Technology представил одноплатник MangoPi MQ-Quad в форм-факторе Raspberry Pi Zero W. Плата основана на процессоре Allwinner H616 максимальная частота 1.5 ГГц, в состав процессора входит 4-ядра Arm Cortex-A53, ARM Mali-T720 GPU, на плате распаяна память объемом 1GB DDR3L и разведен 40-контактный разъем GPIO совместимый с Raspberry Pi. Плата удивляет малыми габаритами и хорошо подходит для компактных систем, так же благодаря низкой стоимости идеально подходит для образовательных задач.
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