longstreet
join:2004-11-14
Plano, TX
4 edits | reply to dietro
Re: High Latency in WoW, North Florida to Boston
It sounds like you're being limited by physical distance and number of hops. It's been some time since I had my theory classes in TCP/IP (> a decade), but if you've done all that . . . i'm stumped to come up with another solution.
Your connection isn't saturated is it? When you test, i'd try testing with a TCP ping / trace program.
Regular windows ping and iirc, tracert are powered by UDP, which isn't reliable when it comes to packet delivery.
Are you seeing packet loss with your dsl reports connection tests?
In any event, the problem isn't wow and likely isn't the servers and connections they are hosted on. |
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NormanS
Premium,MVM
join:2001-02-14
San Jose, CA
 ·Pacific Bell - SBC
| said by longstreet  :In any event, the problem isn't wow and likely isn't the servers and connections they are hosted on. He's got good latency in his own transit networks (Bellsouth and Comcast), so the trouble isn't likely between his equipment and the peer connection to AT&T.
I was reminded by a network guru who knows more than I that routes aren't always symmetrical. The forward path, which is shown by his trace route may not reflect the return path, which can only be seen by running a trace route from the game server back to his connection. If the return path is taking the long way home, he will see weird latency issues. To a great extent, that return path is under Blizzard's control.
--
Norman
~Oh Lord, why have you come
~To Konnyu, with the Lion and the Drum |
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longstreet
join:2004-11-14
Plano, TX
1 edit | Maybe my memory fails me. The routes are almost always different. Can you explain how one of blizzards servers (likely co-located) can 'choose' a path home?
Even if it really is ICMP, it's exactly like UDP in terms of it's reliability.
edit :
Found this
quote:
Many commonly-used network utilities are based on ICMP messages. The traceroute command is implemented by transmitting UDP datagrams with specially set IP TTL header fields, and looking for ICMP Time to live exceeded in transit (above) and "Destination unreachable" messages generated in response. The related ping utility is implemented using the ICMP "Echo request" and "Echo reply" messages.
I guess my memory is good after all. |
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NormanS
Premium,MVM
join:2001-02-14
San Jose, CA
·Pacific Bell - SBC
| said by longstreet :Maybe my memory fails me. The routes are almost always different. Can you explain how one of blizzards servers (likely co-located) can 'choose' a path home? BGP, which I admit to know not a lot about. Something about how networks use BGP to control packet egress (and probably ingress, as well). I expect that it is a cooperative effort for both source and destination. And likely not easy to tweak for latency performance.
--
Norman
~Oh Lord, why have you come
~To Konnyu, with the Lion and the Drum |
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