On May 4, 2010, at 8:02 AM, Dave Hart wrote:
On Tue, May 4, 2010 at 08:54 UTC, Raymond Dijkxhoorn wrote, quoting Patrick:
For emulating cable traffic, latencies (in the USA) will be about 60-80ms to typical sites. [...] For DSL, I seem to recall latency being about 90-110ms (note, I haven't used DSL in many years). [...] The latency i have here on my DSL is ~ 16-22 ms. So its much lower, factor 4...
Either you're looking only at the loop contribution, or you're in the SF bay area and nearly every "typical site" is available locally. Here in the relatively backwater Seattle suburbs, unless it's served by Microsoft or a content distribution network, there are substantial latencies to typical sites.
I am not sure what the point is in mixing in speed of light latency. If your "typical sites" are, say, Indian cricket blogs, you will typically have a high latency from the US. What does that tell you about your DSL or Cable system, except that it is somewhat removed from India ? Regards Marshall
To make it concrete I used Windows ICMP tracert against a few sites from both cable and DSL in the Seattle suburbs. First from a consumer-grade cable offering:
Then from a business-class telco DSL (complete with more than 1 static IP, someone tie me down lest my soul escape my body from sheer joy!):
Note I made no attempt to ensure I was tracing to the same numeric IP address from both, and the tests were simultaneous.
Cheers, Dave Hart
P.S. A special flip of the bird to those IWFs who filter all ICMP at the edge and break path MTU detection.