Hack GPON – how to access, change and edit fibre ONTs

That's how it works in New Zealand, but we take it a step further. The GPON/XGS-PON fibre network is run by a separate company[0] from the ISPs (and the company running the fibre network is prohibited from providing internet services[1]). So the ONT just functions as a media converter[2], and all our ISPs deliver internet over the same fibre network. This decoupling between the fibre network provider and ISP means you can change ISPs without any swapping of ONTs or repatching of fibre[3][4] (in fact, the process can be entirely automated, switching to some ISPs can take effect within an hour or two of placing the order). That and most ISPs allow bringing your own router (as there's no monopoly in the ISP space).

[0]: The NZ Government contracted four companies to build, own, and run fibre networks (three being new companies co-owned by local lines companies and the government to serving their local area, with the rest of the country being served by Chorus, the company that owns the country's copper network). These fibre companies are heavily regulated (including how much they can charge ISPs).

[1]: In fact, this requirement resulted in Telecom (the company that owned our copper network and who was one of the companies that provided phone and internet service to consumers) being split up, with Chorus being spun off, owning the copper network and owning the fibre network for the majority of the country.

[2]: Chorus did start deploying ONTs with a built-in router/AP a while back. They did offer this to ISPs to use, but uptake was very low, so it's since been discontinued.

[3]: I don't know how it works over in European countries where ISPs run their own fibre networks when switching ISPs, I assume they have to either install their own fibre line into the premises or the existing fibre is repatched to their network?

[4]: The fibre companies are required to offer use of their fibre network directly to ISPs, with the ISPs PON network running in parallel to the fibre company's, with the ISP providing their own fibre splitters and ONTs (which would be run on a second fibre line that each premises already has) and running their own OLTs. I believe this requirement still exists, but no-one ever took them up on it.

I agree, and that is a problem. The rules and regulations are different in different countries. In Austria for instance the ISP can force you to use a specific DOCSIS modem or ONT but they have to provide you with a transparent way to connect to it (bridge mode etc.). Which from where I'm standing is a good tradeoff because it gives the ISP the flexibility to do mass migrations without having to consider very old deployed infrastructure.

With PON I think it doesn't matter all _that_ much but for instance people running ancient DOCSIS modems and limited frequency availability has been a massive pain for people stuck with DOCSIS infrastructure that want more upstream and can't.

If you're paranoid, you may want to run an ONT that you control, just in case. I doubt it's something that matters to a lot of people, but even if it only matters to some, it shouldn't be made impossible for those that want to.

RE: misbehaving hardware: the same is very much true for cable internet and there are plenty of countries where people hook up their own modem without any trouble. If someone wanted to mess with the fiber network they could just disconnect the ONT and shine a laser pointer down there. All off-the-shelf devices are built to just work and follow the necessary standards, because there's nothing to be gained by messing with the PON network like that.

It's like saying that Spotify could suddenly decide to retire support for Android 12 or something. They could, but how many customers are they going to lose and how much support burden is that going to generate?

A lot of overhead for ISP support in those cases in which a customer knows they can buy any router with any ONT, plugs it and forgets it without zero knowledge of what a protocol even is.

JTAG is a much lower level protocol, typically used for hardware or low-level software debugging. Serial/UART gives you a command-line interface to the software that's running.

Using a JTAG interface is a lot more complicated. If you're interested in playing with it, check out OpenOCD.

Swisscom pissed away millions of tax payer money after the government ordered an injunction to stop building out on the P2MP network. All they did was continue but just not connect those lines hoping they would win the court cause.

Everything is eventually a shared medium. You don't have your own fiber all the way to Facebook. So the question is just at which point do you share and that should be a decision made on throughput and cost.

I strongly disagree. On a party line information flows along the copper cable to every connected endpoint bidirectionally. While it's true that incoming information flows to all subscribers, never does information that flows out and you only get scrambled data even on the incoming stream. So if you're trying to make a security argument: the system is also safe on a physical level.

> We can do better!

Depends on what "better" is. I was quite critical of PON in the past but I have come around. Practically at this point I think PON is a better way to run networks in most places. At one point you hit a bottleneck anyways and not having to run individual fibers makes for a more resilient and cheaper system.

What is the low end? Austria has a similar problem. There are some quite old and unmaintained AON networks where people are stuck with 100MBit whereas even G.Fast copper eclipses that in some cities at this point.

And when the poor souls on slow internet do get upgraded, AON vs GPON suddenly decides if they can get upgraded to the new higher speeds in the next ten years or not. 1gbps may be relatively slow in 10 years, but with a widely spread GPON you're not getting much more out of that, while with AON entire neighbourhoods can be upgraded by replacing a single rack in the local POP.

> The Object Management Group® Standards Development Organization (OMG® SDO) is a global, open membership, non-profit consortium.