still had one as of a year and a half ago, for bringing in phone lines to a business. they'd converted it a year previous to be SIP over an IP link, though. meh. at that point it was only a tiny smidge better than twilio over business comcast, and was waaaay more of a hassle.
We still sell and use them (small B2B focused clec/isp in Oregon). We use them fairly commonly as dedicated voip links, or for PRI phone systems where the customer insists on avoiding voip. Also in some places they are about the best connectivity you can get when the only alternatives are way oversold dsl or trying to aim a wisp antenna though some trees to catch a signal bounced off a mountainside. And, if you have the means, (and ILEC cabling facilities), the circuits can be bonded together to arbitrary numbers. So, yeah, it's slow. But it's better than nothing. That said I fully expect Starlink to take that ultra-rural business in the coming year or two.
I was still using one until recently. We do inbound phone support and had 24 lines on a T1, because I wanted to make sure I had SLA'ed last-mile connectivity. Previous iteration of this was a 24 line PRI directly into a Sangoma T1/SIP Gateway. After a move + installation, I had an Adtran device that was IP based. It is my understanding that that it was more or less VOIP over a data T1, and the on-premise Adtran device turned it back into a voice T1 for the benefit of our T1 Gateway.
Recently I've switched it to a metro fiber ring + SIP trunking.
It's surprisingly difficult to get SLA'ed SIP trunking in the SMB market.
A few years ago we had one put in for a connection to VisaNET. ISO8353 messages are really small so 1.54Mbps was plenty fast for the number of transactions we were sending.
I'm trying to remember the exact number, but IIRC it was good for a couple of thousand transactions a second.
Indeed, interfacing legacy GSM base stations is the primary use case. However, you can jsut as well use it to interface any other type of E1 equipment, like PBXs etc.
As someone with very little telco knowledge, could you use something like this as a voip gateway for a legacy pbx ?
Would it be as simple as writing some high level software that interfaces with readily available libraries or would more possibly be necessary?
I’m fascinated by the opportunity that all of the legacy circuit switched(pardon me and my naïve googling if that’s the wrong term) hardware has left in critical places.
Ah Harald still at large! I met him in Austria where he gave a training on OsmocomBB (2010? Found the link [0]) and blew me away with his acquired knowledge of GSM. I worked for a large European mobile provider and it was very uncommon to meet people outside of that bubble to be interested, let alone knowledgeable about the domain.
Mind you, at that time there where hardly or no easy accessible & readable write-ups on the subject. Piles and piles of badly formatted and cryptic worded PDF's had to be obtained, read and understood. He did it.
Remember, this was in the same year Karsten Nohl gave his BlackHat presentation on cracking A5/1. Exciting times :)
I saw them do A5/1 live cracking on stage in Netherlands. It is amazing what you can do with sheer determination. Learned a lot from their talks on GSM.
USB E1 is holy grail when it comes to E1 interfaces. Before that meant a PCI card, which excluded all laptops and SBCs. And it usually required some pretty specific kernels and modules to be installed.
Wow, I was looking for a T1/E1 adapter recently for a side project and couldn’t hardly find anything. Sangoma seems to own most of the cards nowadays, and they’re awfully expensive and just awful in general. The only remotely affordable line for me was the Digium line and the documentation for their DAHDI driver outside the brief read me is basically telling you to contact support. And unless you’re using them for an Asterisk setup (I’m not) community support seems to be useless. I ended up paying around $500 for a single port Digium card which I’m not even sure will be able to do what I want now. Other than the expensive Sangoma lines, I was able to find what seemed like a perfect option from GL, except I was quoted $10k, which wasn’t happening. Only other manufacturer I could remotely find was a company making PRI cards that wanted you to fax or email your credit card info. Nice to know there’s another option now.
I have a handful of old ISDN videoconferencing terminals that use the H.320 standard. I’m creating a server that will do things like implement things like multipoint conferencing and bridging to modern video conferencing solutions, although right now I’m stuck decoding the mess of a serial interface they use to connect to the network, which appears to be a slightly non standard V.35 right now.
The equipment for the project has been growing. Outside the expensive E1 device, I still need to get what I need to really simulate that line, including some DCE to take whatever the serial interface on the phone is to an E1 line. I’ve also bought a few old protocol analyzers which weren’t completely necessary, but fun if not mildly useful.
I have used Digium's T1/E1 cards with VPMOCT or VPMADT hardware echo cancellers, but I have since switched to using https://www.rowetel.com/wordpress/?page_id=454 OSLEC for EC as it is simply better and requires much less tuning.
Well the answering service sold itself to a larger answering service, so I no longer work on that. I may one day finish the V2 of my software. The original one was done in 2007 using Asterisk, PHP and COMET (HTTP long polling) and was banged out in 72 hours. It was an emergency situation, where their old setup finally died (circa 1986).
Please note that the icE1usb in its final incarnation with the FPGA based approach was almost entirely done by Sylvain Munaut, not myself. So please give credit to him, and not to me. I only contributed a bit in testing, some patches here and there in the firmware, and the new experimental DAHDI driver for it.
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[ 1.9 ms ] story [ 96.6 ms ] threadRecently I've switched it to a metro fiber ring + SIP trunking.
It's surprisingly difficult to get SLA'ed SIP trunking in the SMB market.
I'm trying to remember the exact number, but IIRC it was good for a couple of thousand transactions a second.
Given osmocom's focus I guess the main point to this for them is talking to base stations that have an e1 port.
Would it be as simple as writing some high level software that interfaces with readily available libraries or would more possibly be necessary?
I’m fascinated by the opportunity that all of the legacy circuit switched(pardon me and my naïve googling if that’s the wrong term) hardware has left in critical places.
Mind you, at that time there where hardly or no easy accessible & readable write-ups on the subject. Piles and piles of badly formatted and cryptic worded PDF's had to be obtained, read and understood. He did it.
Remember, this was in the same year Karsten Nohl gave his BlackHat presentation on cracking A5/1. Exciting times :)
[0] https://deepsec.net/docs/Slides/2010/DeepSec_2010_OsmocomBB.... [1] https://srlabs.de/wp-content/uploads/2010/07/100729.Breaking...
USB E1 is holy grail when it comes to E1 interfaces. Before that meant a PCI card, which excluded all laptops and SBCs. And it usually required some pretty specific kernels and modules to be installed.
There exist Thunderbolt 2 and 3 PCI breakout boxes. Usually they're used for eGPU setups, but they work with pretty much anything.
The equipment for the project has been growing. Outside the expensive E1 device, I still need to get what I need to really simulate that line, including some DCE to take whatever the serial interface on the phone is to an E1 line. I’ve also bought a few old protocol analyzers which weren’t completely necessary, but fun if not mildly useful.