North American Network Operators Group

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Re: multi homing pressure

  • From: Daniel Senie
  • Date: Wed Oct 19 13:38:52 2005

At 01:05 PM 10/19/2005, John Dupuy wrote:

For the customer with an Internet "mission critical app", being tied
to a Tier 2 has it's own set of problems, which might actually be
worse than being tied to a Tier 1.
The key word is "might". In fact, I would posit that a Tier 2 with multiply redundant transit to all of the Tier 1s could theoretically have better connectivity than an actual Tier 1. The Tier 2 transit provides flexibility that the transit-free Tier 1s do not have. Just my opinion.

Anyway, it has been my experience that most (but not all) of the customers that want to "multihome" are _really_ wanting either: A. geographic/router redundancy. or B. easy renumbering. Geographic redundancy can be done within a single AS and IP block. They just don't know to ask it that way. (And easy renumbering will eventually be solved with v6. Eventually.)
It has been my experience that most needing to multihome wish to do so to avoid failures within an ISP, failures with a circuit to the ISP, and failures with routers.

I should think that with the recent L3/Cogent issue, it should be QUITE clear that multihoming requires linking to two separate backbones, or two separate regionals that buy transit from multiple backbones. Vagaries in backbone providers is high on the list, IMO, and rules out the "multihome to a single provider" approach.

The demand for multi-homing might not be as great as suspected.