Peering - Benefits?

Will Hargrave will at
Thu Oct 30 13:37:10 UTC 2008

Paul Stewart wrote:

> We have multiple transit providers today and are already present on a couple
> of smaller peering exchanges with an open peering policy... our experience
> with them has been very positive.

As an IX operator I'm glad to hear it :-)

> The redundancy perspective is that you now have more paths to the same AS -
> and an assumption that the peering route will always be best (I know that's
> not always true).

Something to remember is that you are a network *operator* not a network
*purchaser*. If the peering route isn't working for you, pick up the phone and
talk to your peering partner. The whole point of being a network operator is
that you control who you connect with and take an active hand in fixing
problems! As others have stated, rich interconnection gives you greater
abilities in this area.

> We of course have enough transit in case of a peering outage - would never
> "put all our eggs into one basket" that it sounds like some others are

That attitude is quite 'old-school' - the idea that you can back up your
peering with transit often does not ring true in practice. You have less
visibility into your transit providers network than into your IXes networks,
and what information you do have is clouded by commercial concerns (read: sales

The traffic has to go somewhere, and if everyone in a metro area tries to send
to their transits it will just result in congestion within those networks -
even more likely when you consider the typical way their are built with ports
tiered off at layer2 from routers; traffic in the same metro area is likely to
simply hairpin up/down the router uplink.

Traffic between major transits within a metro area is also subject to
complicated commercial considerations which might mean the connectivity via
that route isn't so great.

> also, we are looking at a number of them in various parts of the world
> currently which adds another level of redundancy per say....

Many metro areas have more than one IX fabric often with considerable numbers
of operators on both. At LONAP in London we have members with big ports
expressly for backing up their private interconnects as well as to back up
sessions at other IXes.

In (primarily) Europe, the Euro-ix website has some useful resources to help
people select IXes: e.g


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