On Sun, 15 Dec 1996, Forrest W. Christian wrote:
By contrast, I can ping any sprint-customer-attached computer and have almost 0% packet loss (1 out of 1000 lost occassionaly).
Providers tend to have better connectivity within their own network.
IS there a reason that I'm getting 5 - 50% loss outside of sprint? I've also played a bit with this from a couple of other providers with similar results.
You paint with a pretty wide brush. The loss is caused by atleast three things: * ICMP packets are dropped by busy routers Many routers drop ICMP packets (ping, traceroute) when busy, or alternate dropping ICMP packets. I know that this behavior occurs when the packets are directed to the specific router, I am not sure if this every occurs for packets passing through. The standby tool ping needs a more reliable replacement for testing end to end packet loss. * Pipe smaller than needed Some providers have a pipes smaller than they "need" going to the NAPs. For a small provider this may be a 10 megabit connection. For sprint even a 100 megabit connection may not be enough (they may need multiple connections). With the Internet continuing to grow you can expect periodic growing pains for specific providers that don't forecast far enough into the future. * Head of queue blocking in the Gigaswitch This primarily effects the traffic of specific providers (who have enough to fill up a 100 megabit pipe). This phenomenon occurs when your NAP connection tries to talk to another providers filled up NAP connection. Even though the Gigaswitch has input and output queues, your output queue will block until the other providers input queue is free. When you block, you drop packets destined for other potentially available connections. However, this usually isn't a problem because most providers don't happen to peer with Sprint (purely an example). In other words, if you don't happen to exchange traffic with the overloaded party you won't see the head of queue problem occur for your packets. This problem can be fixed by multiple connections to the same NAP. (Which many providers already have). To summarize, the ability of a provider to get packets to and from other providers is directly dependent on how much money they are willing to spend to do that. By necessity they improve their internal network first. Mike. +------------------- H U R R I C A N E - E L E C T R I C -------------------+ | Mike Leber Direct Internet Connections Voice 408 282 1540 | | Hurricane Electric Web Hosting & Co-location Fax 408 971 3340 | | mleber@he.net http://www.he.net | +---------------------------------------------------------------------------+