Various people have stated that uneven data flows (e.g. from
mostly-content networks to mostly-eyeball networks) is a good reason to
not peer. I'd love to know how it improves Level 3's network to have
data from Cogent arrive over some *other* connection rather than
directly from a peering connection. Do they suddenly, magically, no
longer have backhaul that mostly-content data across their own backbone
to their users who have requested it if it should come in from one of
their *other* peers who (in normal peering fashion) hot-potato hands it
off to them at the first opportunity, rather than coming in directly
from Cogent?
I don't think so.
So why break off peering???
AFAICT there's only one reason to break off peering, and it's to force
Cogent to pay (anyone) to transit the data. Why does L3 care if Cogent
sends the data for free via peering, or pays someone ELSE to transit the
data?
First off, why do you assume that peering is a right to which people are
entitled? Level 3 operates a network, a pretty darn big and successful one
(well big at any rate), and it apparently does a good job delivering the
bits or it wouldn't have as many customers as it does. Why *must* they
give another network free access to their network if they don't feel that
it is mutually beneficial? You seem to be making the argument that because
YOU think it is mutually beneficial, therefore (3) must be doing something
evil. Beneficial is in the eye of the beholder, and Cogent could just as
easily have been the one to decide it wasn't beneficial to them.
Second, there are serious some serious fallacies in the argument that "the
bits have to go there anyways". The vast majority of the Internet is
multihomed in one way or another, especially the closer you get to the big
Tier 1's. By my count, Level 3 has over 57,000 customer prefixes. I don't
have any data about how many of those Cogent was actually using
before-hand (though I'm sure someone does), but we know that roughly 4,000
some prefixes were single homed and couldn't be reached any other way. I'd
be willing to venture a guess that while Cogent was probably not using
anywhere near 57,000 prefixes from (3), they were using a heck of a lot
more than 4,000 before the depeering notice and traffic depref, and that
those prefixes were substantially trafficked. There is also this thing
called BGP path selection, and one of the important criteria is AS-PATH
length, so making the path to 3356 longer may have diverted a significant
amount of traffic away from Cogent at the source of their multihomed
customers. A depeering would combine both effects, Cogent would
immediately depref, and the longer AS-PATH would shift traffic away from
this path. Even if reaching (3) didn't cost Cogent a dime, depeering may
still have been a viable method of traffic engineering.
The bottom line is that we have no idea what was really going on, but
there are loads of reasons why (3) would want to depeer Cogent that don't
have anything to do with forcing them to pay for transit. I don't think
anyone who depeers another network actually expects to see a dime in
transit business from the depeered network any time in the immediate
future anyways.
I think this is about a big bully trying to force a smaller player off
of the big guys' playing field (tier 1 peering). From where I sit it
looks like an anti-competitive move that is not a "best effort" to serve
their customers but a specific effort to put another (smaller)
competitor out of business (of being a transit-free or mostly
transit-free backbone) by forcing them to pay (someone), forcing their
costs up. Level 3 must know they are no longer putting for a "best
effort" for their own customers to connect them to the "internet" (as
their customers see it, the "complete internet" that their customers
have come to expect).
If Cogent can't stay in business if (3) decides that there is no benefit
to giving them free access to all of their customers, and infrastructure
necessary to deliver it, they were never a peer to begin with. Peering is
about mutual benefit, not entitlement. Cogent makes the same value
judgements when it decides if it is going to peer with another network or
not, it is no different here than it is there. Cogent routinely turns away
smaller peers for peering and suggests that they buy transit instead, are
you going to accuse them of anti-competetive practices next?
I also believe that Cogent has a valid argument that Level 3's behavior
is anti-competitive in a market where the tier 1 networks *collectively*
have a 100% complete monopoly on the business of offering transit-free
backbone internet services. As such, L3's behavior might fall into
anti-trust territory - because if Cogent caves in over this and buys
transit for the traffic destined for L3 then what's to stop the rest of
the tier 1 guys from following suit and forcing Cogent to buy transit to
get to *all* tier 1 networks? Then who will they (TINT) force out next?
What exactly is the business of selling transit-free backbone internet
services? Being a transit free backbone is a silly marketing ploy at best,
at worst it makes you inflexible and vulnerable to exactly the kind of
outages (3) is suffering when someone refuses to transit routes to the.
Besides, I don't think (3) or any of the other large networks are doing
all that well financially with their monopoly.
If anything this makes some strong points about exactly how non-
monopolistic the situation really is. Think about it, despite the fact
that Level 3 provides transit to 1/3rd of the Internet by prefix count (a
silly measurement I realize, but its all I've got :P), the vast majority
of the customers and the Internet manage to route around this particular
issue. That is because the vast majority (over 90% it seems) of (3)'s
customers are multihomed, and those networks can be routed around or donut
peered around.
For example, several large cable MSOs are (3) customers, but peer with
other networks. My company peer with a lot of them, and according to our
netflow statistics we donut around over 95% of the potential traffic that
could go to a (3) peer by peering with their customers and alternate
providers to multihomed customers. This is the kind of thing that is
happening across the world and across the board, most sizable networks are
perfectly capable of bypassing the Tier 1's for the vast majority of the
traffic. In fact that is one of the key reasons why Cogent, a much smaller
company, is as large or larger than (3) in terms of absolute traffic
volume. The Tier 1's are in a losing battle, as more and more of the bits
that they used to handle and bill as on-net traffic is shifted away from
them, and instead move directly between major content networks and major
eyeball networks. It is not unexpected to see them tightening policies
around the customers that they DO have, it is one of the few resources
they have.
What's to stop a big government (like the US) from stepping in and
attempting to regulate peering agreements, using the argument that
internet access is too important to allow individual networks to bully
other networks out of the market - at the expense of customers - and
ultimately resulting in less competition and higher rates? Is this type
of regulation good for the internet? OTOH is market consolidation good
for the internet?
I don't like this slippery slope, I don't like it one little bit.
Hopefully, sanity. Whether you believe it or not, the Internet *IS* best
effort. If you don't like it, or you aren't happy with it, buy from
someone else who makes a better effort. Speaking of slippery slopes, how
would you like to not be able to block traffic to your network from people
you consider to be spam sites, because you are harming global reachability
and potentially trying to force those sites out of business? Same
argument, different benefit for you.