Re: [Starlink] dynamically adjusting cake to starlink

[Nathan Owens <nathan@nathan.io>]

[-- Attachment #1: Type: text/plain, Size: 3280 bytes --]

> This would seem to wind up overloading the downlink to the gateway, as
well
as causing hard to predict fluctuations in bandwidth.   This is definitely a
complex situation where I can see buffers being added looks like a good
cure-all.

We'll find out soon enough... Polar launches start in July.

> Do you know how traffic is being steered?  I.e. how does the Gateway say
which terminal traffic is to?  All we know is that tweet "Simpler than IPv6"
Some kind of SDN, but based upon what kind of discriminators?
Are there circuits involved (ala ATM or PPPoE), tags like MPLS or 802.1Q?

My intuition would be that traffic is encap'd when it enters a PoP based on
the destination IP, and the state of the constellation. The encapsulation
could just be MPLS with a segment routing-like approach, it would contain
the desired gateway, satellite, and terminal ID.

On Wed, Jun 9, 2021 at 2:18 PM Michael Richardson <mcr@sandelman.ca> wrote:

>
> Mike Puchol <mike@starlink.sx> wrote:
>     > This is correct, with a few twists once you throw in inter-satellite
>     > links. In future satellite versions, optical
>     > links will allow satellites within the same orbital plane to use each
>     > other as relays, thus providing coverage in areas not within a
>     > gateway’s coverage.
>
> This would seem to wind up overloading the downlink to the gateway, as well
> as causing hard to predict fluctuations in bandwidth.   This is definitely
> a
> complex situation where I can see buffers being added looks like a good
> cure-all.
>
> Allowing for direct terminal to terminal traffic would ultimately help
> as many of the latency sensitive things like gaming and video calls are
> often
> rather local.
>
>     mcr> (Also, we talk about uplink/downlink from the point of view of
> the the end
>     mcr> user station. But, are there better terms from the satellite's
> point of
>     mcr> view to distinguish traffic to/from the end user?)
>
>     > In general, downlink is anything from satellite to ground, be it
>     > satellite -> gateway or satellite -> terminal, and uplink the reverse
>     > path. These are the clearest terms to use IMHO. Thus, if satellite to
>     > terminal has 75/25 DL/UL duty cycle, the satellite to gateway link
> will
>     > be reversed, with 25/75 DL/UL duty cycle.
>
> Yeah, so in order to speak usefully about some of this stuff, I think we
> need
> to distinguish between traffic going "up" which is going towards the
> Gateway,
> from traffic which might be going "up" from the Gateway (or across from
> another satellite).  Some additional terms would help.  I had hoped that
> there were some :-)
>
> Do you know how traffic is being steered?  I.e. how does the Gateway say
> which terminal traffic is to?  All we know is that tweet "Simpler than
> IPv6"
> Some kind of SDN, but based upon what kind of discriminators?
> Are there circuits involved (ala ATM or PPPoE), tags like MPLS or 802.1Q?
>
> --
> ]               Never tell me the odds!                 | ipv6 mesh
> networks [
> ]   Michael Richardson, Sandelman Software Works        |    IoT
> architect   [
> ]     mcr@sandelman.ca  http://www.sandelman.ca/        |   ruby on
> rails    [
>
>

[-- Attachment #2: Type: text/html, Size: 4303 bytes --]