North American Network Operators Group

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Re: multi homing pressure

  • From: Todd Vierling
  • Date: Wed Oct 19 12:22:27 2005

On Wed, 19 Oct 2005, Elmar K. Bins wrote:

> > Tier-2s should be given much more credit than they typically are in
> > write-ups like this.  When a customer is single homed to a tier-2 that has
> > multiple tier-1 upstreams, and uses a delegated netblock from the tier-2's
> > aggregations, that means one less ASN and one or more less routes in the
> > global table.
> That's the operators' view, but not the customer's.
> The customer wants redundancy.

That's why SLAs exist.

> So we should try to find a way to tell them "Hey, it's mostly Tier-1's
> (or wannabes) that play such games, stick to a trustworthy Tier-2.
> And, hey, btw., connect redundantly to them, so you have line failure
> resiliency and also a competent partner that cares for everything else."

Something like that, but not quite.  Whenever one of these reports, which
boil down to "everyone must multi-home!", appears, it typically has a stark
lack of information on alternatives to *direct* multi-homing.

Many customers would rather not multihome directly, and prefer "set it and
forget it" connectivity.  It's much easier to maintain a multi-pipe
connection that consists of one static default route than a pipe to multiple
carriers.  The former requires simple physical pipe management, which can be
left alone for 99% of the time.  The latter requires BGP feed, an ASN, and
typically much more than 1% of an employee's time to keep running smoothly.

Obtaining single-homed connectivity from a Tier-2 mostly "outsources"
network support, and small to medium size businesses tend to like that.
It's not the only leaf end solution to the problem, but it's a viable one
(and can be less costly to the rest of the world in turn).

-- Todd Vierling <[email protected]> <[email protected]> <[email protected]>