IP: End-to-end philosophy endangered

[Dave Farber <farber () central cis upenn edu>]

From: "David P. Reed" <dpreed () reed com>
Subject: End-to-end philosophy endangered


Friends -


I'd like to call your attention to a situation where misguided politics (of
the "ends-justify-means" sort) threatens one of the fundamental principles
of Internet architecture, in a way that seems like a slippery slope.
I do not normally take public stands of a political nature, and I do not
participate much in Internet architecture anymore, but I'd like to call your
attention to a very severe perversion of the Internet architectural
philosophy that is being carried out in the name of political and commercial
expediency.  No matter what you believe about the issues raised by the
Communications Decency Act, I expect that you will agree that the mechanism
to carry out such a discussion or implement a resolution is in the
agreements and protocols between end users of the network, not in the groups
that design and deploy the internal routers and protocols that they
implement.  I hope you will join in and make suggestions as to the
appropriate process to use to discourage the use of inappropriate
architectural changes to the fundamental routing architecture of the net to
achieve political policy goals.


As you know, I am one of the authors, along with Saltzer and Clark, of the
paper "End-to-end arguments in decentralized computer systems", which first
characterized in writing the primary approach to the Internet's architecture
since it was conceived, which approach arguably has been one of the reasons
for its exponential growth.  This philosophy - avoid building special
functionality into the net internals solely to enforce an end-to-end policy
- has led to the simplicity, low cost, and radical scalability of the
Internet.  One of the consequences is that IP routers do not enforce
policies on a packet-by-packet basis, so routers can be extremely simple
beasts, compared to the complex beasts that characterize even the simplest
telephone central office switch.  End-to-end policies are implemented by
intelligence at the ends (today, the PCs and servers that communicate over
the many consolidated networks that make up the Internet).


I just read in Inter@ctive weekly that Livingston announced an "Exon box" -
a router that is designed to enable ISPs to restrict access to "indecent
sites" or unrated sites unless an "adult" enters an authorization code when
opening a session to enable the router to  transmit packets to the site.


The scam seems to be that Livingston has colluded with Senator Exon's staff
to propose a "solution" to enable ISP's to implement parental controls.
Exon's staff is using the announced solution as an example to demonstrate
how simply ISPs can enforce local community standards and parental controls,
thus supporting interpretations of the CDA requiring all access providers to
include such capability in their boxes.  Exon's staff is quoted as
encouraging ISP's to install such functionality into the routers that serve
as access points for nets.


Since I use an Ascend P50 ISDN router to make frequent, short,
bandwidth-on-demand ISDN connections from my "Family LAN" to an Ascend
multi-line ISDN router at my commercial Internet Service Provider, I am
worried that this model is completely unworkable for me, and for others that
will eventually use such a practical system.  My family has minor children
and adults who all happily access the Internet.  My ISP has no clue
whatsoever whether a child or adult has initiated the call, and in fact, if
my child and I are both on different computers in different rooms, it is
quite silly to imagine that the Ascend router at the ISP can figure out if
it is me or my child generating each packet.


It is appalling to me that Livingston, which has some responsibility as a
router provider to assist in the orderly growth of the net, is pandering to
Exon's complete misunderstanding of how the Internet is built.  I would hope
that Ascend, with its much larger share of the ISP market, and other router
companies such as Cisco and Bay Networks, would take a principled and likely
popular position that the "Exon box" is not the way to go about this.  I
would hope that ISP's would in general avoid use of Livingston's products,
and also refuse to cave into Exon's pressure.  I believe, though I may be
wrong, that Livingston has contributed to the RADIUS technology that many
ISP's use to manage dialup access charging in a way that is consistent with
ethe end-to-end philosophy, but any credit they are due is overwhelmed by
the Exon box insanity.


I do work to protect my children from inappropriate material, but pressure
from Senators to mandate technically flawed solutions, and opportunistic,
poorly thought-through technologies from companies like Livingston are not
helpful.


If you agree, please join me in attempting to call off any tendency for
other router vendors and protocol designers to develop Exon box features.
It would seem that the appropriate place for content restrictions, such as
"parental controls", are in the end-to-end agreements between content
providers and their users, not in the internal switching architecture of the
net.
- David