Hello Nanog community, I would like to enlist your help with understanding this latency I'm seeing. First some background, I have Level3 circuits in the US and some services in Europe. From Comcast to the US level3 IPs the performance is excellent. The same traceroute to Europe is terrible. The strange part is the problem appears to begin stateside on the same infrastructure that carriers the us traffic. Here is a trace to one of my IPs in the US from Comcast Tracing route to 4.30.x.x over a maximum of 30 hops 1 3 ms 1 ms 1 ms 10.1.1.1 2 30 ms 29 ms 29 ms 71.62.150.1 3 9 ms 9 ms 9 ms xe-0-1-0-32767-sur01.winchester.va.richmond.comc ast.net [68.85.71.165] 4 9 ms 14 ms 10 ms xe-9-0-3-0-ar02.staplesmllrd.va.richmond.comcast .net [68.86.125.149] 5 32 ms 30 ms 34 ms 68.86.91.153 6 36 ms 38 ms 53 ms 23.30.207.98 7 34 ms 28 ms 33 ms vlan51.ebr1.Atlanta2.Level3.net [4.69.150.62] 8 29 ms 28 ms 20 ms ae-63-63.ebr3.Atlanta2.Level3.net [4.69.148.241] 9 27 ms 29 ms 30 ms ae-2-2.ebr1.Washington1.Level3.net [4.69.132.86] 10 24 ms 30 ms 24 ms ae-71-71.csw2.Washington1.Level3.net [4.69.134.1 34] 11 29 ms 31 ms 39 ms ae-41-90.car1.Washington1.Level3.net [4.69.149.1 95] 12 30 ms 30 ms 29 ms ae-2-23.edge7.Washington1.Level3.net [4.68.106.2 38] 13 38 ms 44 ms 43 ms 4.79.x.x 14 * * * Request timed out. (My firewall) 15 39 ms 39 ms 39 ms 4.30.x.x Trace complete. Now here is the same computer tracing to a level3 circuit in Ireland. Tracing route to xxx.yyy.ie [193.1.x.x] over a maximum of 30 hops: 1 1 ms 1 ms 1 ms 10.1.1.1 2 38 ms 33 ms 25 ms 71.62.150.1 3 10 ms 9 ms 9 ms xe-0-1-0-32767-sur01.winchester.va.richmond.comc ast.net [68.85.71.165] 4 14 ms 15 ms 15 ms xe-9-0-3-0-ar02.staplesmllrd.va.richmond.comcast .net [68.86.125.149] 5 28 ms 30 ms 30 ms 68.86.95.65 6 37 ms 37 ms 37 ms 23.30.207.98 7 118 ms * 218 ms vlan51.ebr1.Atlanta2.Level3.net [4.69.150.62] 8 119 ms 218 ms 119 ms ae-63-63.ebr3.Atlanta2.Level3.net [4.69.148.241] 9 221 ms 119 ms 119 ms ae-2-2.ebr1.Washington1.Level3.net [4.69.132.86] 10 118 ms 119 ms 118 ms ae-91-91.csw4.Washington1.Level3.net [4.69.134.1 42] 11 119 ms 119 ms 119 ms ae-92-92.ebr2.Washington1.Level3.net [4.69.134.1 57] 12 117 ms 126 ms 120 ms ae-43-43.ebr2.Paris1.Level3.net [4.69.137.57] 13 128 ms 118 ms 120 ms ae-6-6.car1.Dublin3.Level3.net [4.69.148.53] 14 122 ms 225 ms 124 ms 4.69.148.58 15 124 ms 118 ms 120 ms ae-11-11.car1.Dublin1.Level3.net [4.69.136.93] Notice that the hop from 23.30.207.98 to 4.69.150.62 seems very respectable at around 30ms for US bound traffic. However when I'm tracing from the same Comcast network to an IP that is in Europe the very same hope produces 100ms of latency and about 12% packet loss. Why does this hop treat traffic differently based on it's destination? Is this some weird result of complex asymmetrical routing or something else? I can route around this problem, but it does seem strange and I want to understand it Thanks, Sam Moats