Internet Packet Loss - MTR

Hello! It seems like there should be a subreddit for this kind of thing, but I haven't found it yet. Apologies if you feel this is not appropriate for here, but I suppose it is something you folks deal with.

I'm getting occasional heavy packet loss between NYC HE and London NCUK, as observed between my VPS in Los Angeles and a pingbox tester in London:

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 1.|-- _gateway 0.0% 60 0.4 0.5 0.3 1.5 0.2 2.|-- unassigned.psychz.net 0.0% 60 0.9 10.4 0.7 172.6 32.5 3.|-- [redacted] 0.0% 60 0.7 1.2 0.5 7.2 1.5 4.|-- v807.core1.lax2.he.net 0.0% 60 2.9 7.0 0.6 23.6 8.8 5.|-- 100ge2-2.core1.lax1.he.net 0.0% 60 4.0 10.2 0.6 56.2 12.1 6.|-- 100ge12-1.core1.ash1.he.net 0.0% 60 58.7 62.4 54.9 94.4 10.0 7.|-- 100ge1-1.core1.nyc4.he.net 0.0% 60 60.4 62.2 60.3 74.9 2.9 8.|-- 100ge7-1.core1.lon2.he.net 20.0% 60 140.9 141.8 140.5 151.8 2.3 9.|-- ??? 100.0 60 0.0 0.0 0.0 0.0 0.0 10.|-- po11-13.bdr-rt3.thdo.ncuk.net 15.0% 60 218.5 163.5 162.1 218.5 7.9 11.|-- po4-31.core-rs4.thdo.ncuk.net 23.3% 60 165.1 166.6 165.1 179.6 2.7 12.|-- [redacted] 30.0% 60 168.3 168.5 168.2 169.8 0.3 

I have always been a bit confused by an MTR such as this. I do understand that packet loss at any one hop does not mean the packets are stopping there, for example if by hop 12 loss was back to 0% it wouldn't matter if the routers in between returned the pings themselves.

So in this case, is it a problem between hop 7 and hop 8 meaning HE is overloaded crossing the pond, or more likely is it the interconnection between HE and NCUK is overloaded and dropping packets and the 20% loss at lon2.he.net is not really a problem?

Then once I do know who to blame, are there any effective ways to report it?

(I can't get an MTR in the other direction because I don't control the London endpoint machine)

Thanks!