nanog mailing list archives
Re: 60 ms cross-continent
From: Tim Požár <pozar () lns com>
Date: Sat, 20 Jun 2020 10:07:08 -0700
Besides the refractive index of glass that makes like go about 2/3rds it can in a vacuum, "Stuff" also includes many other things like modulation/demodulation, buffers, etc. I did a quora answer on this you can find at:
https://www.quora.com/How-can-one-describe-the-delay-characteristics-of-ping-and-traceroute-commands/answer/Tim-Pozar On 6/20/20 9:29 AM, Joe Greco wrote:
On Sat, Jun 20, 2020 at 09:24:11AM -0700, William Herrin wrote:Howdy, Why is latency between the east and west coasts so bad? Speed of light accounts for about 15ms each direction for a 30ms round trip. Where does the other 30ms come from and why haven't we gotten rid of it? c = 186,282 miles/second 2742 miles from Seattle to Washington DC mainly driving I-90 2742/186282 ~= 0.015 secondsSpeed of light in a fiber is more like 124K miles per second. It depends on the refractive index. And of course amplifiers and stuff. ... JG
Current thread:
- 60 ms cross-continent William Herrin (Jun 20)
- Re: 60 ms cross-continent Joe Greco (Jun 20)
- Re: 60 ms cross-continent Tim Požár (Jun 20)
- Re: 60 ms cross-continent Tim Durack (Jun 20)
- Re: 60 ms cross-continent Tim Durack (Jun 20)
- Re: 60 ms cross-continent Dave Cohen (Jun 20)
- Re: 60 ms cross-continent Mel Beckman (Jun 20)
- Re: 60 ms cross-continent Wayne Bouchard (Jun 20)
- Re: 60 ms cross-continent Saku Ytti (Jun 20)
- Re: 60 ms cross-continent Bryan Fields (Jun 20)
- Re: 60 ms cross-continent Martin Hannigan (Jun 20)
- Re: 60 ms cross-continent Saku Ytti (Jun 20)
- Re: 60 ms cross-continent Tim Durack (Jun 20)
- Re: 60 ms cross-continent Tim Požár (Jun 20)
- Re: 60 ms cross-continent Joe Greco (Jun 20)