8 ms·
> Because the speed of light in a vacuum is 30% faster than in optical fiber, the latency of Starlink over long distances has the potential to be lower than any
by dahfizz 6y ago
> Because the speed of light in a vacuum is 30% faster than in optical fiber, the latency of Starlink over long distances has the potential to be lower than any other option once laser links are available.
Not to mention the dramatic reduction of hops. My route from the USA east coast to the university of Melbourne in Australia[1] is 30 hops reported by traceroute, with at least as many switches in the way. You could make the same link with only a few satellites.
[1]www.ie.unimelb.edu.au
EDIT: 30 is actually just the default max hops in traceroute, its really 32 hops from me to Melbourne.
- 0xffff2 6y agoI wonder how many hops it will actually remove. I just tested it, and from my apartment in Mountain View, CA to my VPS in a data center ~20 miles away in Fremont, CA I get 14(!) hops.
- kbenson 6y agoIt's all about peering. Once they're in more exchanges, and it becomes cost effective to set up peering with them, more traffic will reach them directly asdifferent providers set up peering to both reduce costs across other links and provide better access.
- dahfizz 6y ago> I wonder how many hops it will actually remove. Hopefully a lot! Fun fact, IPv4 and IPv6 have a maximum network size. Because of the TTL field in v4 (renamed max hops in v6), a path through an IP network can never be more than 255 hops long.
- xxpor 6y agoYou can tunnel though, so the actual amount of hops could be infinite. Routers can also rewrite the field.
- dahfizz 6y agoAnd just like NAT with IPv4, we will use hacks to get around implementing a proper solution for decades (and counting). With satellite internet taking off, and actual interest in extraterrestrial colonies from e.g. NASA and SpaceX, I think we need a proper space communication protocol. Maybe it can all be solved in L2, but I think we will soon be looking at 255 hops the way we look at the limited address space of v4.
- nitrogen 6y agoIt seems people are working on this: https://en.wikipedia.org/wiki/Interplanetary_Internet https://en.wikipedia.org/wiki/Interplanetary_Internet
- rmdashrfstar 6y agoThanks for posting this, reading about all the progress made with delay tolerant networking is exciting!
- AdrianoKF 6y agoInteresting (but probably not too surprising) to see that DTN research is alive and kicking! I wrote a short seminar paper on DTN protocols as an undergrad in '09, so thanks for the trip down memory lane!
- tinus_hn 6y agoHops are artificial, as long as you are 100% sure you’re not introducing loops you can just tell routers not to decrease the TTL and they’ll be invisible. It’s just that if you do that and you do introduce a loop the packets will keep looping and the network will very quickly overflow.
- aeyes 6y agoIt all depends on peering, I get 13 hops to some networks in Europe which is some 12.000km away from here (7500 freedom units).
- shaklee3 6y agoMentioned above, but it won't. The hops are up and down to boats instead of routers.
- dicknuckle 6y agothere's probably double or triple the switches in between. they're not really switches though. more like super fast packet routers. the latency is much less than any normal or carrier grade switch. they don't touch the IP layer at all. (I manage a bunch of them)
- walrus01 6y agoone of the things I keep telling non-network-eng people is that looking at a traceroute gives you absolutely no way of knowing what the OSI layer 2 topology is for transport networks, MPLS, switches, DWDM circuits carried as lit services "glassed through" a location, etc. Just the IP network. Discovering the underlying layer 2 topology of a carrier's network requires inside information and cannot be easily discerned sitting at a computer elsewhere on the internet. You might see two routers that appear to be directly adjacent to each other but it's actually carried as a 10Gbps VLAN across a several-state sized region between two cities many hundreds of km apart, with a lot of intermediate equipment in between.
- gpm 6y ago100km = 3 light-ms - which should be noticeable in the relative pings, no?
- walrus01 6y agoYes, I mean it can be obvious when ISPs have proper consistent reverse DNS with hostnames and POP designations. You might see a router in Sacramento that is a neighbor of something in Portland. Obviously there's a lot of stuff in between there but it's all abstracted away at the purely layer-3 IP network level.
- chupasaurus 6y agoYou've missed one zero, 1 light-ms = 300km.
- tlamponi 6y ago
- redis_mlc 6y ago> Because the speed of light in a vacuum is 30% faster than in optical fiber Non-Australians, don't get too excited. Those satellites are at 340 miles, so that adds 680 miles of latency (3.66 ms) plus two to three Starlink hops, which cancels out some of that "speed in a vacuum." The way to get almost c on earth is via direct microwave links.
- cryptonector 6y ago> The way to get almost c on earth is via direct microwave links. But line of sight. Short-haul.
- davedx 6y agoYou'd be surprised how far HFT companies run their microwave link networks to get better latencies :) https://sniperinmahwah.wordpress.com/2014/09/22/hft-in-my-backyard-part-i/ https://sniperinmahwah.wordpress.com/2014/09/22/hft-in-my-ba...
- ed_blackburn 6y agoFrom one space elevator to the next. Yeah?
- redis_mlc 6y agoFYI: both Canada and the US have had transcontinental RF links. The repeaters slow down the transmission by about 30%. However those were fairly low-bandwidth.
- Retric 6y agoThe minimum latency is 3.66 ms, but depending on the angle to the satellites involved it may be adding significantly less than 680 miles to the journey. Aka if it’s 340 miles east and 340 miles up that’s 480 miles to the satellite, adding just 140 not 340 miles. Outside of HFT, most networks are far from the shortest great circle routes between you and the other end, which further completes the issue.
- hanniabu 6y agoThis brings up thoughts of The Hummingbird Project (a movie) https://youtu.be/vnXLYr6U3bk https://youtu.be/vnXLYr6U3bk
- kitteh 6y agoIt's a bad movie. The true story is that a company (spread networks) spent many millions building a low latency fiber path between chicago and nyc. Two guys built a lower latency radio network that connected a number of cell towers together and were the first to market rendering that cable obsolete. Within months other people had radio networks up to try to compete (to give an idea about how competitive that space is).
- throwaway9d0291 6y agoI'm in Switzerland and have 25 hops, which can be broken into: - 1-7: Hops within my ISP's in-country network (~4ms total latency) - 8-10: Hops within my ISP's in-Europe network (~28ms total latency) - 11: London -> New York (~93ms total latency) - 12: New York -> Los Angeles (~160ms total latency) - 13: Transfer in LA from my ISP to AARNet (about the same latency) - 14: LA to somewhere in NSW (guessing Sydney, 305ms total latency) - 15-25: Routing within AARNet and Unimelb (319ms total latency) So most of the latency looks to be attributed to large hops across oceans rather than internal switching. Even if you could narrow it down to London -> NY -> LA -> NSW you'd have 277ms.
- ThreeFx 6y agoInit7 gets there in 15, they reach AARNet directly from their presence in LAX, however it still takes ~310ms to reach NSW.
- throwaway9d0291 6y agoHuh, my ISP is Init7 and as I said, takes 25 steps to get there, though steps 18-24 inclusive show as "waiting for reply" in MTR. Init7's traceroute [0] shows 5 fewer steps to r1lon2.core.init7.net than my traceroute though and appears to route through r1bsl1 (assuming Basel) instead of Frankfurt. Perhaps you're in/near Basel and so skip straight to London, circumventing my 8 hops around Zurich? [0]: https://www.as13030.net/traceroute.php https://www.as13030.net/traceroute.php
- imtringued 6y agoThose numbers seem awfully high. I've just ran a speedtest between Germany and California and got 170ms total latency. Back when rabb.it [0] was alive I could even get reaction scores of 450ms compared to 230ms when running the test on my computer. This is quite impressive when you consider that this means video encoding and decoding must happen in less than 50ms. Conventional video encoding is usually slower than real time. [0] https://en.wikipedia.org/wiki/Rabb.it https://en.wikipedia.org/wiki/Rabb.it (Californian startup) [1] https://humanbenchmark.com/tests/reactiontime https://humanbenchmark.com/tests/reactiontime
- Hikikomori 6y agoRouters and other equipment do not add very much delay unless packets sit around in the buffer, and for that you need congestion.