Upstream bandwidth usage
Raymond Burkholder
ray at oneunified.net
Thu Jun 9 23:58:28 UTC 2022
On 2022-06-09 17:35, Michael Thomas wrote:
>
> On 6/9/22 4:31 PM, Mel Beckman wrote:
>> Adam,
>>
>> Your point on asymmetrical technologies is excellent. But you may not
>> be aware that residential optical fiber is also asymmetrical. For
>> example, GPON, the latest ITU specified PON standard, and the most
>> widely deployed, calls for a 2.4 Gbps downstream and a 1.25 Gbps
>> upstream optical line rate.
>
> Why would they mandate such a thing? That seems like purely an
> operator decision.
There are also vendor issues involved. I am glad that Mel mentioned
'optical line' rate. Which becomes a theoretical thing. If the line
cards aren't set up with buffering properly, then line rate won't be
seen. And I think the line cards can also be easily over-subscribed.
Oh, and due to the two or three step fan-out of 8/16/32, upstream
becomes even more limited.
So, if you have FTTH with 1::1 house::port, then you are cooking with
fire. Else, it is the luck of the draw in terms of how conservative the
ISP is provisioning a GPON infrastructure. Which, I suppose, depends if
it is 1G or 10G GPON.
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