4 ms·

Current generation 12 slot chassis with 51.2Tbps per slot is 612Tbps per chassis, and so a pair is 1228Tbps which is roughly your estimate. Companies like Junip

Current generation 12 slot chassis with 51.2Tbps per slot is 612Tbps per chassis, and so a pair is 1228Tbps which is roughly your estimate. Companies like Juniper and Cisco sell tens of thousands of the previous generation per year _today_. Starlink is not even a drop in the bucket in terms of forwarding. Moreover, with a very tiny exception over antarctica or open ocean, every single packet forwarded by starlink is hitting a terrestrial link after a single ground-space-ground hop. Nobody is going to be making backbones out of Starlink or anything that looks like Starlink. Only the people who know nothing about modern networking performance think otherwise.

Retric 3y ago
If you followed the thread, my estimate was ~3,000 TBps, welterde gave “1.7 - 2.3 Pbit/s” = 1700 to 2300 TBps. 1228 TBps is well below both of our estimates. Last I checked global IP traffic it’s still well under 2,000 TBps looking at the rate traffic is increasing Starlink really can act as a major internet backbone. Also, Starlink customer to Starlink customer is very compelling for may applications. Undersea cables for example can create much higher latency between areas than their physical separation for example Australia to Madagascar. Similarly there’s still quite a bit of point to point microwave tower connections etc that can now be cheaply replaced.
- welterde 3y ago
  You are not comparing the same thing here though. If you applied the same theoretical maximum method to all networking hardware (or even just core router class hardware) sold today you would arrive at numbers very very much in excess of a couple Pbit/s. For it to be really viable as a backbone it would need to be able to do several 100 Gbit/s from one location and that Starlink cannot do (or is built to do). A single satellite has less than 100Gbit/s of RF capacity and you will only have a couple visible above you at any one time. And after that bottleneck comes the inter-satellite link capacity bottleneck which is less than half of that if the information I have found is correct (4 links à 10Gbit/s). I don't think they will be able to sell more than 10 GBit/s service to anyone and that only in not so populated areas. A single datacenter can reach low Tbit/s of connectivity _alone_ _today_. I don't see how it could make any dent whatsoever in the backbone market. The other usecases are a different discussion and not as dependent on very high bandwidth numbers.
  - Retric 3y ago
    Core routing hardware isn’t sold at multiple Pbit/s because no location on earth has that much traffic. Nobody is wasting that kind of money buying hardware when they don’t have fiber to make use of it. Starlink is aiming physically to eventually have 10+ Pbit/s worth of actual hardware because customers aren’t spread evenly across the globe so there’s inefficiencies involved. The only unfairness is comparing future equipment to current equipment. First data centers very wildly in size and have connections to multiple networks for redundancy, Starlink would be very appealing from that standpoint. Also you’re underestimating bandwidth here, V2 mini are ~80Gbps full V2 weigh 2.5x as much and presumably the bandwidth difference is even higher, but they aren’t launching hardware yet so it’s unclear. Any given location several satellites above it at the current density, at 42,000 you’re talking 50+. Plus if it’s data center to Starlink customer then you’re effectively replacing a Starlink ground station so they might make such installations very cheap.
    - welterde 3y ago
      Every packet traverses multiple such core routers (most likely from multiple internet providers), so 1 Tbit/s from A to B requires many more Tbit/s of actual hardware capacity sold. Or take the edge capacity of small FTTH providers and you get to quite large theoretical numbers too. Hundreds of Tbit/s easily if one is offering Gbit/s or faster service (my ISP has around 1Tbit/s of equipment installed just to service around a 300m radius of residential homes). Both are true for Starlink as well: In case both source and target are not visible to the same satellite they have to be routed via multiple hops or sent upstream (ground station) to the rest of the internet. The edge capacity (RF up/downlink) boasts insane numbers, but the actual internal backbone is much more limited. For consumer it is less of an issue since they won't mostly fill up that 1Gbit/s service they have, but businesses will absolutely fill that up (so you can oversell much less). Starlink doesn't have nice overview of actual specs of future satellites, so I can only use what people have figured out or what they have published. But you are right about the number of satellites, I looked at the wrong column (it was for phase 1 and not 3), so density will indeed be much higher, so from that perspective it will be somewhat more capable (depending on fast/slow their rollout is). And it's not clear if it would actually be cheaper for SpaceX to have such customers (since some of the traffic would go to the rest of the internet - requiring ground station resources) or go elsewhere on the planet (filling up inter-satellite capacity), but that's not too much different from how regular ISPs have to plan (some customers are cheaper for them than others).

Retric 3y ago

If you followed the thread, my estimate was ~3,000 TBps, welterde gave “1.7 - 2.3 Pbit/s” = 1700 to 2300 TBps. 1228 TBps is well below both of our estimates. Last I checked global IP traffic it’s still well under 2,000 TBps looking at the rate traffic is increasing Starlink really can act as a major internet backbone. Also, Starlink customer to Starlink customer is very compelling for may applications. Undersea cables for example can create much higher latency between areas than their physical separation for example Australia to Madagascar. Similarly there’s still quite a bit of point to point microwave tower connections etc that can now be cheaply replaced.

welterde 3y ago
You are not comparing the same thing here though. If you applied the same theoretical maximum method to all networking hardware (or even just core router class hardware) sold today you would arrive at numbers very very much in excess of a couple Pbit/s. For it to be really viable as a backbone it would need to be able to do several 100 Gbit/s from one location and that Starlink cannot do (or is built to do). A single satellite has less than 100Gbit/s of RF capacity and you will only have a couple visible above you at any one time. And after that bottleneck comes the inter-satellite link capacity bottleneck which is less than half of that if the information I have found is correct (4 links à 10Gbit/s). I don't think they will be able to sell more than 10 GBit/s service to anyone and that only in not so populated areas. A single datacenter can reach low Tbit/s of connectivity _alone_ _today_. I don't see how it could make any dent whatsoever in the backbone market. The other usecases are a different discussion and not as dependent on very high bandwidth numbers.
- Retric 3y ago
  Core routing hardware isn’t sold at multiple Pbit/s because no location on earth has that much traffic. Nobody is wasting that kind of money buying hardware when they don’t have fiber to make use of it. Starlink is aiming physically to eventually have 10+ Pbit/s worth of actual hardware because customers aren’t spread evenly across the globe so there’s inefficiencies involved. The only unfairness is comparing future equipment to current equipment. First data centers very wildly in size and have connections to multiple networks for redundancy, Starlink would be very appealing from that standpoint. Also you’re underestimating bandwidth here, V2 mini are ~80Gbps full V2 weigh 2.5x as much and presumably the bandwidth difference is even higher, but they aren’t launching hardware yet so it’s unclear. Any given location several satellites above it at the current density, at 42,000 you’re talking 50+. Plus if it’s data center to Starlink customer then you’re effectively replacing a Starlink ground station so they might make such installations very cheap.
  - welterde 3y ago
    Every packet traverses multiple such core routers (most likely from multiple internet providers), so 1 Tbit/s from A to B requires many more Tbit/s of actual hardware capacity sold. Or take the edge capacity of small FTTH providers and you get to quite large theoretical numbers too. Hundreds of Tbit/s easily if one is offering Gbit/s or faster service (my ISP has around 1Tbit/s of equipment installed just to service around a 300m radius of residential homes). Both are true for Starlink as well: In case both source and target are not visible to the same satellite they have to be routed via multiple hops or sent upstream (ground station) to the rest of the internet. The edge capacity (RF up/downlink) boasts insane numbers, but the actual internal backbone is much more limited. For consumer it is less of an issue since they won't mostly fill up that 1Gbit/s service they have, but businesses will absolutely fill that up (so you can oversell much less). Starlink doesn't have nice overview of actual specs of future satellites, so I can only use what people have figured out or what they have published. But you are right about the number of satellites, I looked at the wrong column (it was for phase 1 and not 3), so density will indeed be much higher, so from that perspective it will be somewhat more capable (depending on fast/slow their rollout is). And it's not clear if it would actually be cheaper for SpaceX to have such customers (since some of the traffic would go to the rest of the internet - requiring ground station resources) or go elsewhere on the planet (filling up inter-satellite capacity), but that's not too much different from how regular ISPs have to plan (some customers are cheaper for them than others).