Subject: [RRG] The Map-Encap "third party" problem

From: Brian Dickson <[email-masked]>
Date: Thu, 21 Feb 2008 20:57:21 -0500

William Herrin wrote:
>
>>  The problem is a spam-like asymmetry.
>>
>>  The problem with spam is, one party pays (the ISP delivering mail, and
>>  the end user ultimately) for the benefit of another party (the spammer).
>>     
>
> That is a remarkably insightful description of BGP PI as it exists today.
>   
Actually, I was referring to the ITR/ETR model. The ITR bears a large 
burden of the operation costs,
scaling, performance, etc, while the benefit goes to the "other" guy at 
the ETR end - the multi-homed guy.

However, thinking about that, made me realize there is a *huge* issue on 
the operational aspect of any
tunnel-based solution.

As soon as the packets are tunneled, you lose visibility on what is 
happening.

And if you aren't the guy doing the tunneling, you *really* lose 
visibility, and in turn, accountability,
the ability to localize and diagnose problems, and generally you are 
left twisting in the wind
if anything goes wrong. Which it will.

But, unlike, say, VPNs, this isn't a localized set of sites, in a closed 
community. This is the whole Internet,
getting to your site.

The lack of visibility means you are now dependent on not only your 
local-end ISPs, but also lots of third
parties, with whom you have *no* contractual relationship.

It also opens up the "net neutrality" thing to abuse, on a much grander 
scale. If you can't prove that someone
is doing something fishy (e.g. by showing traceroutes), what chances are 
there that you can protect yourself
from systematic abuse or extortion by providers? The ability to measure 
performance is the common denominator
that makes it possible to guarantee a level playing field. ITR/ETR 
removes that completely.

There are alternatives to ITR/ETR architectures that may be feasible and 
may scale adequately.

IMHO, it behooves us to pay more attention to those alternatives.

Brian Dickson
P.S. I've discussed an alternative before - I'll do so again in the near 
future if there is interest expressed...

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---

From: "William Herrin" <[email-masked]>
Date: Thu, 21 Feb 2008 23:49:49 -0500

On Thu, Feb 21, 2008 at 8:57 PM, Brian Dickson <[email-masked]> wrote:
>  Actually, I was referring to the ITR/ETR model.

I know but it struck me as such an apt description of BGP PI that I
felt compelled to comment.

>  As soon as the packets are tunneled, you lose visibility on what is

To some extent, yes. I discuss this a little at
http://bill.herrin.us/network/trrp-breaks.html

Regards,
Bill Herrin

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William D. Herrin [email-masked] [email-masked]
3005 Crane Dr. Web: <http://bill.herrin.us/>
Falls Church, VA 22042-3004