[ NNSquad ] Re: Dave Farber Warns AgainstNetNeutrality (Washington Post)I

[Peter Eckersley <pde@eff.org>]

On Wed, Sep 30, 2009 at 01:33:11PM +0200, Kriss Andsten wrote:
 
> It's not about you, it's about us. Networks are shared.
> 
> If you're saying that a reduction in price when the network can't
> deliver is a good way to go, then you never met a WoW priest with a
> laggy connection.
> 
> WoW will average 10 Kbps. BitTorrent tend to average quite a bit
> more per user - let's say 2 Mbps (which can be on the lower end, but
> unlike WoW, BT speeds tend to differ greatly depending on where in
> the world you happen to reside).
> 
> In terms of resources, 200 WoW =~ 1 BT. TCP/IP also tend to reward
> applications that are anti-social over applications that try to
> behave, which compounds the problem somewhat.
> 
> Let's put 200 BT users and 200 WoW users on the same network. 200
> WoW users, 2 Mbps. 200 BT users, 400 Mbps. Grand total, 402 Mbps.
> Now let's limit the available bandwidth on our theoretical network
> to introduce congestion. Pick a number between 50 and 400.
> 
> Prioritizing the bandwidth for the WoW users over the bandwidth for
> the BT users will yield a negligible impact for the BT users, but
> will keep countless raids going since the healers and tanks won't be
> lagged to hell. 200 happy WoW users (not to mention their
> guildmates) and 200 BT users who didn't even notice.
> 
> Sure, it's a very theoretical network with only BitTorrent and
> Warcraft traffic, but you get the idea.
> 
> Of course, there's many ways of skinning that particular cat, many
> ways of prioritizing traffic and introducing some sort of fairness
> equation. No arguing there - DPI isn't the holy grail by any means,
> just a rather useful tool at hand. Traffic management of some sort,
> however, is pretty much required - 'Some sort of fairness' doesn't
> happen as if by magic.

I don't think I have any disagreements with the facts above, except the
conclusion that DPI should be in the first box of tools an *ISP* reaches for
in dealing with the WOW/BT problem.  The first thing a provider can/should do,
if it's seeing congestion that's bad enough to drop the packets of users with
who just want one stable 10kbps flow, is protocol- and content-independent
per-subscriber load balancing.  If the network doesn't support that in the first
hop, it can be done with a load balancer doing Random Early Detection or
something simliar, further along the path.

Now you may still have a point in that some users might want to be able to
have a LAN with lots of hosts running WOW-like and BT-like code
simultaneously, and they might want DPI-based prioritisation across their own
applications and machines.  That might make sense too, but offer that product
to subscribers as configurable (and ideally, standardised) feature of a NAT
router, not as mandatory policy implemented further into the network.  That
way a mistake in the prioritisation policy won't mess up the user's
applications in a way that the user can't fix.

-- 
Peter Eckersley                            pde@eff.org
Staff Technologist                Tel  +1 415 436 9333 x131
Electronic Frontier Foundation    Fax  +1 415 436 9993