Quote Originally Posted by fisamo View Post
An open question:
I am a cable subscriber, and let's say for discussion that I get 20ms pings to sip.voipwelcome.com. Is it not possible (perhaps even likely) that should my next-door neighbor have a DSL connection, they could see 100ms pings to the same server, simply because they use a different ISP and traffic gets routed differently? 'Worse' yet, if my ISP is Earthlink over TWC and my neighbor is a TWC Road Runner customer (presuming we're on the same cable node), could our ping times differ? Would they necessarily be the same for two customers on the same node with the same ISP? (I'm assuming that to be the most likely case that they'd be the same... )
It all depends on the "Peering" for that ISP backbone. See the following for details

http://en.wikipedia.org/wiki/Peering

There are about 8 NAPs in major cities around the country. That's where the switching happens. If the source and destination has peering happens close to you then you will get lower ping times and lower number of hops. Major providers have equipment in the NAP.

Regarding Earthlink, its been a while, but I think TWC provides only the cable. DNS, routers, DHCP server are all different for Earthlink and RR. But I would think peering will happen in the closest NAP.

BTW, my ping times are about 50-60ms and I don't have any problems with the SIP servers.