[Starlink] Starlink tidbits from NANOG

[Ulrich Speidel]

Thanks for that Darrell - that's really interesting! A few comments on 
that front:

On 5/11/2021 4:26 am, Darrell Budic wrote:
> I was at NANOG in Minneapolis, and got a chance to ask a couple 
> question of a Starlink Network Engineer who’s attending. I was already 
> talking to him about Starlink’s network efforts (see below) but it was 
> nice to meet in person. Don’t quote me on any of this, but here’s a 
> few tidbits this list may appreciate:
>
> - Starlink is expanding their own network operations, and is 
> connecting to more IXPs. They were already on SIX in Seattle, have 
> connected to DECIX NY, and are in the process of connecting to ChIX in 
> Chicago. As I run ChIX, I had a good excuse to talk to them about 
> other things. :) IXPs and their own networks are in the works for 
> Europe and other areas as well.
Makes sense.
> - They have been obtaining more v4 addresses, but I don’t know if they 
> have enough to not do CGNAT. I don't think they do yet, but it seems 
> like it may be a long term target.
> - v6 is deliberately not fully functional, but they know some of use 
> are using it and it will eventually be fully activated. May be waiting 
> on the regional connectivity, so will be intersting to see if changes 
> for some areas and not others as they roll it out.

So I guess we need to distinguish between:

- IPv4 addresses for any CGNAT they might run
- IPv4 addresses as static addresses for (some of?) their customers
- IPv6 addresses as customer addresses
- IPv6 addresses to support geographic routing as discussed in earlier 
posts (subnet maps to cell / satellite)

There are quite a number of feasible configurations in this. E.g., they 
could be running a CGNAT setup with a v4 pool on the Internet side, use 
v6 to tunnel route from there to the satellite the end customer connects 
to, and then map that customer back to a (private) IPv4 address in a NAT 
on the satellite. One aspect that hasn't really been mentioned much here 
is that of PDU size on the link between end customer and satellite. 
Keeping Dishy and its successors small and cheap creates an incentive to 
operate at marginal SNR, and this favours smaller PDUs over larger ones 
as the probability of PDU checksum errors increases with PDU size. But 
having lots of small PDUs means having lots of headers, and as IPv4 
addresses are leaner than IPv6 ones, this saves bandwidth here. Probably 
not a biggie though.
> - New ground stations with more capacity are coming (and will be 
> upgrades). 
Any word on where? At the moment, most of the world can see Starlink 
satellites, but most Starlink satellites can't see a ground station.
> They are using waves back to regional DCs now, but will be moving to 
> dark fiber over the next year or two
If that means "radio" waves, then this goes a long way to explaining why 
there's already limited capacity even near the US-Canada border.
> - the new satellites have more than 2 lasers, and there is enough 
> capacity on them to do routing. no details on how or what protocols, alas
Any word on when we can expect to see routing in action?
> - new birds also have 2-3x more ku bandwidth than first gen
Hm. Sounds cool, but with 3 billion or so underserved on the planet & 
typical annual growth rates, that's still just a drop in the bucket.
> - new dishes are in the works, v4 coming with lower power use, more 
> capacity, not round any more
Trayee? Squary? Just joking ;-)
> - larger dishes coming for commercial apps
That's good news, as this will allow Starlink to be used in places where 
direct-to-site crashes into regulatory hurdles. If we can get the big 
CDN providers to come up with small (virtual?) appliances that can be 
put at the remote end of such links by local ISPs, then that'll also 
help to preserve space segment capacity.

-- 
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Dr. Ulrich Speidel

School of Computer Science

Room 303S.594 (City Campus)
Ph: (+64-9)-373-7599 ext. 85282

The University of Auckland
ulrich at cs.auckland.ac.nz
http://www.cs.auckland.ac.nz/~ulrich/
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