On 09/02/2024 18:07, The Natural Philosopher wrote:
> On 09/02/2024 16:00, Andy Burns wrote:
>> Brian Gregory wrote:
>>
>>
> Actually you don't need to do that at all, all customers *downstream*
> signals are present on your fibre.
>
> You just have to do a brute force attack on the encryption keys...
>
>>
>
Just been skim reading the ITU spec for GPON (G984.6)also BT sin 506-1
and there is no encryption mentioned.

All customer OLT end points are single fibre working using the same 2
frequency's (wavelengths) of light, 1 for upstream 1 for downstream.
Each single fibre is then connected to a port an optical splitter (32 or
64 )the output of which connects to an optical switch and then into the
greater network.

Its 20 years since I did any fibre builds but even back then 64
wavelength per port optical switches where available, if eye wateringly
expensive.

grinch wrote:

> Just been skim reading the ITU spec for GPON (G984.6)also BT sin 506-1
> and there is no encryption mentioned.

Have a look at G.984.3

On 12/02/2024 08:58, Andy Burns wrote:
> grinch wrote:
>
>> Just been skim reading the ITU spec for GPON (G984.6)also BT sin 506-1
>> and there is no encryption mentioned.
>
> Have a look at G.984.3
>
https://www.itu.int/rec/dologin_pub.asp?lang=e&id=T-REC-G.984.3-201401-I!!PDF-E&type=items

section 12.2

--
Future generations will wonder in bemused amazement that the early
twenty-first century’s developed world went into hysterical panic over a
globally average temperature increase of a few tenths of a degree, and,
on the basis of gross exaggerations of highly uncertain computer
projections combined into implausible chains of inference, proceeded to
contemplate a rollback of the industrial age.

Richard Lindzen

On 12/02/2024 09:54, The Natural Philosopher wrote:
> On 12/02/2024 08:58, Andy Burns wrote:
>> grinch wrote:
>>
>>> Just been skim reading the ITU spec for GPON (G984.6)also BT sin
>>> 506-1 and there is no encryption mentioned.
>>
>> Have a look at G.984.3
>>
> https://www.itu.int/rec/dologin_pub.asp?lang=e&id=T-REC-G.984.3-201401-I!!PDF-E&type=items
>
> section 12.2
>
Thanks for that ,interesting why use encryption when you can use DWDM ?

The NSA and GCHQ will not be pleased

grinch <grinch@somewhere.net> wrote:
> On 12/02/2024 09:54, The Natural Philosopher wrote:
>> On 12/02/2024 08:58, Andy Burns wrote:
>>> grinch wrote:
>>>
>>>> Just been skim reading the ITU spec for GPON (G984.6)also BT sin
>>>> 506-1 and there is no encryption mentioned.
>>>
>>> Have a look at G.984.3
>>>
>> https://www.itu.int/rec/dologin_pub.asp?lang=e&id=T-REC-G.984.3-201401-I!!PDF-E&type=items
>>
>> section 12.2
>>
> Thanks for that ,interesting why use encryption when you can use DWDM ?
>
> The NSA and GCHQ will not be pleased
>

It’s in the clear at the Fibre Exchange/Headend.

On 12/02/2024 13:28, grinch wrote:
> On 12/02/2024 09:54, The Natural Philosopher wrote:
>> On 12/02/2024 08:58, Andy Burns wrote:
>>> grinch wrote:
>>>
>>>> Just been skim reading the ITU spec for GPON (G984.6)also BT sin
>>>> 506-1 and there is no encryption mentioned.
>>>
>>> Have a look at G.984.3
>>>
>> https://www.itu.int/rec/dologin_pub.asp?lang=e&id=T-REC-G.984.3-201401-I!!PDF-E&type=items
>>
>> section 12.2
>>
> Thanks for that ,interesting why use encryption when you can use DWDM ?

For the same reason you use a front door key instead of a rolled up
newspaper?

>
> The NSA and GCHQ will not be pleased

The only men in the middle of a passively split fibre optic network are
other potential customers.

Data is unencrypted at the far end of the fibre.

--
For every complex problem there is an answer that is clear, simple, and
wrong.

H.L.Mencken

grinch wrote:

> The Natural Philosopher wrote:
>
>> https://www.itu.int/rec/dologin_pub.asp?lang=e&id=T-REC-G.984.3-201401-I!!PDF-E&type=items
>> section 12.2
>
> Thanks for that ,interesting why use encryption when you can use DWDM ?

Because they don't want to use a lambda per customer (with all the
complication of supplying matching "colour" ONTs*) they want to reserve
other lambdas for 10Gbps, 25 Gbps etc FTTP

[*] Though I have seen something about SPFs which can "tine" to
different wavelengths.