did AS174 and AS4134 de-peer?

All -

I was noticing that it appears from our Seattle-based full route feed from cogent that they may have de-peered AS4134 (or vise-versa)... anyone know anything about this? We noticed this recently in a shift of traffic away from cogent for traffic to and from china telecom... Now cogent's path is _174_1239_4134_.

In any case, was just wondering if anyone had noticed this. AS4134 is one that often generates NOC calls on our end due to their often saturated peers to any number of other upstreams and the cogent route had been remarkably uncongested previously so it is sad to see it disappear.

John @ AS11404.


cheers, --jim

Isn't this journalism a bit yellow? No facts / based on speculation..

- Greg

Now all they need to do is link back to this NANOG thread as a source.

That would be very irresponsible. Otoh, if someone updated the tier1 network page on Wikipedia first...


There is no change to the list. Cogent still does not have transit. Cogent sees CT through Sprint (a peer) because CT pays Sprint for transit.

OTOH, Jim did say in his blog post: "This disconnection will increase China Telecom's transit costs...." This assumes facts not in evidence, namely that the CT <-> Sprint pipes were not full before the de-peering incident.

Heh. I think Doug was pretty clear in his summary of the observed facts,
at least. There was a healthy, longstanding routing adjacency, observed by
all. Right sharp at the top of the hour (10:00pm in China, 9:00am Eastern
time), that connection disappears from global view. Afterward, the
percentage of the Renesys peer base that likes transit paths to CT through
Sprint ticks up modestly.

The real story there is hidden in that traceroute latency plot. Look how
neatly it bifurcates post-event into paths through Sprint and paths through
Level3. Notice that paths through Level3 tend to have slightly lower
latencies and significantly less volatility. Infer what you will about the
congestion on the Sprint-CT pipe.

As a meta-comment: this "Quick Look" style of blog is an experiment we're
trying, based on feedback that the community wanted to hear about more of
these little events as they happen. In a Quick Look, we're giving the
facts as they are known from initial measurement, and a very quick summary
of our preliminary analysis of the incident. Then we throw the topic open
to comments from those who might have the clues to the rest of the story ...

cheers, --jim

Well, this member of the community appreciates it.


I find the combination of facts and inferences presented to be interesting and useful.



- Eric