nanog mailing list archives
Re: Starlink routing
From: Michael Thomas <mike () mtcc com>
Date: Sun, 22 Jan 2023 15:16:58 -0800
On 1/22/23 3:05 PM, Matthew Petach wrote:
On Sun, Jan 22, 2023 at 2:45 PM Michael Thomas <mike () mtcc com> wrote: I read in the Economist that the gen of starlink satellites will have the ability to route messages between each satellite. Would conventional routing protocols be up to such a challenge? Or would it have to be custom made for that problem? And since a lot of companies and countries are getting on that action, it seems like fertile ground for (bad) wheel reinvention? MikeUnlike most terrestrial links, the distances between satellites are not fixed,and thus the latency between nodes is variable, making the concept of "Shortest Path First" calculation a much more dynamic and challengingone to keep current, as the latency along a path may be constantly changing as the satellite nodes move relative to each other, without any link state actuallychanging to trigger a new SPF calculation.
One thing that is in their favor is that while they are moving, they are moving in a predictable manner. It seems that each router could, essentially, locally update routes until they are told otherwise?
I suspect a form of OLSR might be more advantageous in a dynamic partialmesh between satellites, but I haven't given it as much deep thought as wouldbe necessary to form an informed opinion.So, yes--it's likely the routing protocol used will not be entirely "off-the-shelf"but will instead incorporate continuous latency information in the LSDB,and path selection will be time-bound based on the rate of increase in latencyalong currently-selected edges in the graph.
Has IETF looked at this, do you know? Even if the routers can't interoperate with other systems, it would be good to have some routing clue with a lot of eyeballs on it to not make rookie mistakes.
Mike
Current thread:
- Starlink routing Michael Thomas (Jan 22)
- Re: Starlink routing Matthew Petach (Jan 22)
- Re: Starlink routing Michael Thomas (Jan 22)
- Re: Starlink routing Jorge Amodio (Jan 23)
- Re: Starlink routing Masataka Ohta (Jan 23)
- Re: Starlink routing Jorge Amodio (Jan 23)
- Re: Starlink routing Masataka Ohta (Jan 23)
- Re: Starlink routing Jorge Amodio (Jan 23)
- Re: Starlink routing Masataka Ohta (Jan 24)
- Re: Starlink routing Michael Thomas (Jan 22)
- Re: Starlink routing Matthew Petach (Jan 22)
- Re: Starlink routing Tom Beecher (Jan 22)
- Re: Starlink routing Raymond Burkholder (Jan 22)