Hi Dave,
> On Jan 13, 2022, at 16:28, Dave Taht <dave.t...@gmail.com> wrote:
>
> yes, well, I dislike intensely the implications of
> not-so-intelligently splitting those 128 terminals is, and was pleased
> to see there was support
Nobody in their right mind is going to hook up 128 terminalt to one OLT
port, I hope...
> at least, for hardware flow control on the uplink side in the spec.
The spec, as many ITU documents contains probably more than anybody is
going to use ;)
But GPON uses a request-grant system for upstream scheduling similar to DOCSIS
(when looking at both from great height), just with a much faster message clock
and hence less total and especially less variability in delay, if I understood
things correctly.
> Since we've fixed dsl, cable, and wifi, getting gpon more right has
> increasingly
> been on my mind...
Fist question might to be "how broken is GPON/XGPON" to start with, no?
> so pulling a testbed together of some sort would
> be cool, and for that matter, having a SFP that could go right into a
> SFP enabled home router rather than a separate unit seems like a good
> idea, also.
Meh, unless you actually get root on the ONU, it will basically act
like a small media converter whether you connect via SFP or via ethernet. In
Germany enthusiasts started to look at SFP-ONUs partly because ISPs were
provisioning more GPON "rate" than required for that the ~940 Mbps goodput of
gigabit ethernet, going SFP allowed some to run (compatible SFP-onus) at 2.5
Gbps link rate to the SFP cage hence allowing speedtest superiority... (that
and to clone ONUs so you can have a replacement in the cupboard in case your
original dies; typicallY ONUs need to be individually provisioned by the ISP
but if you have a perfect clone all the ISP would see is a short power-down).
The upshot of this is that some found ways onto SFP onus so you can get more
information from the ONU if you are really dedicated. But first you need an
GPON link and an ISP that will provision whatever ONU you selected... (ITU
envisioned the ONU to be part of the ISPs network and hence little thought was
spend on ideas like giving the end user root on those devices). And that is
where I am out, currently FTTH-built out is a big topic at home, but has not
reached my flat yet and might not for a few years (oh, the irony, as I am
living literally next door to a central office of the incumbent telco, spanning
a fiber cable over less then 20 m should get me FTTH, but I digress)
Regards
Sebastian
>
>
> On Thu, Jan 13, 2022 at 6:51 AM Sebastian Moeller <moell...@gmx.de> wrote:
>>
>> Yes sorry,
>>
>> in GPON you have the unit at the telco side, often called OLT (optical line
>> termination/terminal or similar, which feeds the whole segment of up to ~128
>> remote terminals and receives data from all) the passive splitter (if any)
>> and the remote customer units that are called either ONU or ONT, but that
>> are just two names for the same unit (not sure who uses which nomenclature,
>> the local incumbent seems to prefer ONU, but their marketing name is
>> Glasfasermodem, which just translates to fiber-modem). Nomenclature seems ot
>> be consistent for the whole PON family, so in XG-PON or XGS-PON the unit
>> apparently still are called OLT and ONU/ONT. And given that PON requires
>> some smarts and configurability of the ONUs these tend to be small computers
>> in their own right with their own little (or not so little) OSes.
>>
>> Regards
>> Sebastian
>>
>>
>>
>>> On Jan 13, 2022, at 15:38, Dave Taht <dave.t...@gmail.com> wrote:
>>>
>>> And a gpon onu
>>>
>>> https://www.fs.com/products/133619.html
>>>
>>> On Thu, Jan 13, 2022 at 6:23 AM Sebastian Moeller <moell...@gmx.de> wrote:
>>>>
>>>> That is similar to what happens in some GPON-ONT SFPs, some run a full
>>>> small Linux distribution like OpenWrt inside.... though for ethernet that
>>>> is unexpected.
>>>> This is also similar to SFP VDSL "modems" which likely run their own
>>>> embedded OS as well inside the SFP package (at a time there was even a PCI
>>>> VDSL2 "modem" that was actually running its own embedded system on the PCI
>>>> board, IIRC, it pretended to the main computer to be an ethernet NIC).
>>>>
>>>> Regards
>>>> Sebastian
>>>>
>>>>
>>>>
>>>>> On Jan 13, 2022, at 15:18, Dave Taht <dave.t...@gmail.com> wrote:
>>>>>
>>>>> running linux, of course.
>>>>>
>>>>> https://blog.benjojo.co.uk/post/smart-sfp-linux-inside
>>>>>
>>>>> --
>>>>> I tried to build a better future, a few times:
>>>>> https://wayforward.archive.org/?site=https%3A%2F%2Fwww.icei.org
>>>>>
>>>>> Dave Täht CEO, TekLibre, LLC
>>>>> _______________________________________________
>>>>> Cerowrt-devel mailing list
>>>>> Cerowrt-devel@lists.bufferbloat.net
>>>>> https://lists.bufferbloat.net/listinfo/cerowrt-devel
>>>>
>>>
>>>
>>> --
>>> I tried to build a better future, a few times:
>>> https://wayforward.archive.org/?site=https%3A%2F%2Fwww.icei.org
>>>
>>> Dave Täht CEO, TekLibre, LLC
>>
>
>
> --
> I tried to build a better future, a few times:
> https://wayforward.archive.org/?site=https%3A%2F%2Fwww.icei.org
>
> Dave Täht CEO, TekLibre, LLC
_______________________________________________
Cerowrt-devel mailing list
Cerowrt-devel@lists.bufferbloat.net
https://lists.bufferbloat.net/listinfo/cerowrt-devel
