FWIW, I enabled the TBB BQM for my line yesterday, both v4 and v6.
What I see is:
- lots of yellow on the
IPv6 address
- occasional yellow spikes on the
IPv4 address (coinciding with similar on the IPv6)
If I understand the BQM service description correctly, the yellow line gives the maximum RTT out of 100 pings, so in effect it's the 99th percentile.
This doesn't match with my own measurements. For example, trying 500 pings to Google's IPv6 DNS over 100 seconds:
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6 | root@nuc1:~# ping6 -q -i0.2 -c500 2001:4860:4860::8888
PING 2001:4860:4860::8888(2001:4860:4860::8888) 56 data bytes
--- 2001:4860:4860::8888 ping statistics ---500 packets transmitted, 500 received, 0% packet loss, time 100035ms
rtt min/avg/max/mdev = 4.783/5.166/5.388/0.081 ms |
You can see average 5.166 and maximum 5.388 - this is extremely flat and consistent.
However, if I do the same to 2a02:68:1::164 which is the address I see the TBB BQM measurements coming in from:
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6 | root@nuc1:~# ping6 -q -i0.2 -c500 2a02:68:1::164
PING 2a02:68:1::164(2a02:68:1::164) 56 data bytes
--- 2a02:68:1::164 ping statistics ---500 packets transmitted, 500 received, 0% packet loss, time 100193ms
rtt min/avg/max/mdev = 3.964/5.349/33.999/3.083 ms |
And again:
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6 | root@nuc1:~# ping6 -q -i0.2 -c500 2a02:68:1::164
PING 2a02:68:1::164(2a02:68:1::164) 56 data bytes
--- 2a02:68:1::164 ping statistics ---500 packets transmitted, 500 received, 0% packet loss, time 100193ms
rtt min/avg/max/mdev = 4.040/5.709/38.884/3.948 ms |
There are your spikes: peaks in the region of 34-39ms.
Repeating the Google test again:
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6 | root@nuc1:~# ping6 -q -i0.2 -c500 2001:4860:4860::8888
PING 2001:4860:4860::8888(2001:4860:4860::8888) 56 data bytes
--- 2001:4860:4860::8888 ping statistics ---500 packets transmitted, 500 received, 0% packet loss, time 100059ms
rtt min/avg/max/mdev = 4.677/5.170/6.801/0.137 ms |
Still flat as a pancake.
Therefore, it seems likely that the current BQM spikiness issue is either with the transit/peering between Cerberus and TBB's upstream ISP (
NetConnex AS21396), or with the TBB monitoring.
Seeing some IPv6 BQM results for non-Cerberus endpoints would help, so I've just added one for the Google IPv6 DNS address: live graph
here and it looks very flat so far.
For me, traceroute to Google and to TBB both goes via the same LINX peering subnet, 2001:7f8:4:1::X:X. It's possible the return traffic is taking a different path though.
This may or may not be the same issue as the one seen last week, where people were affected by serious loss and latency in real-world applications (e.g. VOIP). Given that Cerberus users' BQM graphs were flat before, it seems likely that it's a lesser version of the same issue.