Is openwrt the right OS for GPON ONT devices?

Hardware Questions and Recommendations
1

Such as this one - the Nokia ONT:

This device has a Realtek RTL9601B

I suppose a more relevant question is - is it worth it? It's nice to know you're in control of your own device, but the firmwares on these ONT devices generally perform as well as can be. And to match such performance usually takes a while for owrt to achieve.

Interesting to know whether anyone here has taken a crack at these devices.

2

That is going to be a matter of opinion, and I suspect the opinions here may be quite wide. For an ONT, though, which is basically little more than an interface, I don't see the value added in pushing OpenWrt there.

I think you've hit the nail on the head. It's like putting OpenWrt on a dedicated cable modem - not a lot of value added to justify the effort. The value added is OpenWrt on the device downstream of the ONT - your switch, router, access point, or combo device.

3

There are a lot of reasons why you would use openwrt over something custom made. Cost is the obvious one. But other than that off the top of my head first is upgrade. You can put everything in config files and do a sysupgrade remotely (ISPs like doing this) which is easy and proven. Second is that openwrt has tons of documentation for you to build you packages and what not. Basically openwrt provides a base that is easy to build on and relatively stable.

The features we are used to here like routing and sqm and what not are not important for it but some of the advantages of openwrt can be leveraged without spending a lot on development costs and can be quickly out the door into customers hands.

4

For reference I also have a Nokia SFP which doesn't support 4 port emulation. My ISP does need that so even with spoofing the GPON settings I am unable to use it cause SFP interface will simply disable. It runs openwrt. I wish I could rebuild it to support this.

5

The old lantiq/intel Falcon platform used for some GPON-ONTs essentially runs an old version of OpenWrt internally, so yes OpenWrt can be the right OS for ONTs, however I am not sure whether one can easily recompile/upgrade that OpenWrt version, but there are instructions around how to modify this OpenWrt configuration to e.g. 'clone' identifying feartures from one ONT to another (e.g. used to replace an ISPs stand-alone ONT with an SFP-ONT, some folks really want the WAN interface inside their router).

6

The questions would be:

  • is there toolchain (gcc, binutils, musl, etc.) support for the SOC
  • is there SOC support in mainline linux (or can it be reasonably added)
  • are there drivers for the fibre interface
  • do the SOC system requirements meet OpenWrt's limits (>=16 MB flash, >=128 MB RAM)
  • is there a way to get the GPON feature working (presumably the answer to this is 'no')
  • is the SOC fast enough to be a reasonable target (including the network interfaces <-- proprietary hardware offloading?)

…if all of these questions can be answered in the affirmative, then yes, running OpenWrt can make sense (but I guess you're getting the first 'no' answers pretty early in that list).

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7

Thanks for the comprehensive replies.

Mainly notes to self for later:

I'm musing here, but the Realtek RTL9601B SDK is something called Luna - Linux based. So one could get a copy using the GPL.

Although there are PRs merged already which added support, at least for the Realtek RTL9601C variant. There appear to be sources out there for B variant.

8

Just judging from the sparse information around these ONTs, the G-010G-Q likely comes with 16 MB flash (7 MB usable) and 32 MB RAM, which isn't going to fly with OpenWrt.

And personally speaking (I do have the G-010G-P myself), what would you want to do with these anyways?
Single fibre port in, single ethernet port out - it's in front of your router's WAN (and the ONT isn't powerful enough to route itself) and a simple media converter (technically this is a lie, for GPON it has to do more, but on a functional level that is what you're getting out of it) of your ISP's network just sitting in your house - don't trust it, don't touch it - just feed it with power and secure your own router behind it.

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9

100% concur - although this still does not quell the temptation to experiment (short of writing to the flash).

I've read similar a sentiment countered elsewhere and above, but integrating the SFP directly into the router or another switch at home could be nice.

Some complexity lies within...

gpon

10
Sad that we essentially complicate our life unnecessarily with POM and the resulting request/grant shared medium access gunk instead of going fully AON where all that is needed would be a comparatively dumb fiber PHY part. Sure PON saves on fibers, power, and space (in the CO) over AON, but also requires to place active ISP gear like PON-ONTs into end user premises. Since the ISPs (understandably) want to keep control of their network, they try to keep the ONTs under lock as much as possible. But endusers also want control over their networks...

There are already existing GPON ONTs in SFP form factor that operate OpenWrt internally...

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11

That the user is in control of devices on their premises, seems to be the main motivation here. But Internet/WiFi is like the new bottom layer of Maslow's hierarchy of needs, and when it breaks, people start to go crazy. :sweat_smile:

That OEMs also run OWRT on some ONT partially answers the question that it is at least suitable for the devices.

12

ISPs want to be able to change Wi-Fi channels and passwords remotely. It saves them so many support calls. People can log into the app and change router settings without having access to Wi-Fi. This level of automation won’t sound great for people who want control of their network but literally 99% of the customers don’t care. They just want to pay a monthly fee and get fast wifi than can be fixed with a call to customer support.

13

I doubt that anybody really wants to pay monthly fees... For ISPS that is a different issue, saving support calls (and hence cost) as well as banking a monthly additional payment, what is not to love about that....

So I was around when the www revolution came to town... we quickly saw that even smallish devices grew a web page that ca be used to make changes without having to rely on dedicated configuration software/applications. That worked pretty well. I this should also operate over wan access all it needs is for the router to also have a VPN server instantiated.

Having seen ISP hotline actions, I for one am very reluctant to hand these guys root access to my network...