Hi,

I'm currently seeing considerable latency between my Zen ADSL and LINX, the London Internet Exchange, which carries a great deal of Internet traffic in and out of Zen's network.  This seems like a pretty serious problem.

I can typically expect latency of no more than 25ms to LINX, but it can be seen in my traceroute below that latency is around 80ms.  This most annoyingly affects my connection to game servers where the latency makes it impossible to play.

I believe the issue may relate to a router at LINX with IP address 195.66.224.243, which I guess is rented to or colocated for Zen.  It is important to note that LINX's looking glass facility shows ~60ms latency, and some packet loss, when trying to ping or traceroute to this router from a different host also within LINX. I imagine 10-gigabit fibre links are used within LINX and so I would expect latencies under 1ms and zero packet loss.  I think this points toward some problem with the router itself, rather than the link between it and Zen's core network.

 traceroute to 195.66.224.243 (195.66.224.243), 30 hops max, 40 byte packets
 1      galileo-sub-lb.zen.net.uk (62.3.82.19)
11.928 ms       12.185 ms       12.455 ms       11.792 ms       12.342 ms       11.739 ms       12.043 ms       11.282 ms       11.353 ms       12.033 ms

 2      lotze-ge-0-0-1-140.hq.zen.net.uk (62.3.80.141)
12.026 ms       11.748 ms       13.956 ms       11.774 ms       11.542 ms       11.903 ms       12.723 ms       12.728 ms       12.358 ms       11.991 ms

 3      nietzsche-ae2-0.ls.zen.net.uk (62.3.80.70)
14.025 ms       12.812 ms       12.511 ms       13.518 ms       12.703 ms       13.542 ms       13.060 ms       13.001 ms       18.938 ms       12.561 ms

 4      nozick-ge-3-1-0-0.ls.zen.net.uk (62.3.80.74)
13.315 ms       12.657 ms       12.277 ms       12.766 ms       13.717 ms       12.300 ms       20.887 ms       12.548 ms       12.531 ms       12.969 ms

 5      lorenz-ge-3-0-0-0.te.zen.net.uk (62.3.80.78)
21.701 ms       21.414 ms       21.738 ms       22.857 ms       21.063 ms       20.535 ms       22.350 ms       21.183 ms       21.456 ms       21.556 ms

 6      leibniz-ge-2-0-0-0.te.zen.net.uk (62.3.80.42)
21.011 ms       20.713 ms       20.888 ms       21.418 ms       21.332 ms       21.438 ms       20.643 ms       21.007 ms       21.659 ms       20.813 ms

 7      195.66.224.243 (195.66.224.243)
82.979 ms *     83.329 ms * * * 89.885 ms *     86.982 ms *

Values shown are round-trip times for sequences of 10 40-byte UDP packets.  Up to and including the 6th hop, leibniz, no packet loss is seen and latency appears normal.  The asterisks denote lost packets at the 7th hop;  60% in this case.

Regards,

-- 

Steven Chamberlain

steven@pyro.eu.org