The Qos PipeDream [Was: RE: Two Tiered Internet]

Fri Dec 16 03:01:39 UTC 2005

On Thu, 15 Dec 2005 19:15:49 -0500 (EST)
Sean Donelan <sean at donelan.com> wrote:

> AT&T, Global Crossing, Level3, MCI, Savvis, Sprint, etc have sold
> QOS services for years. Level3 says 20% of the traffic over its

What do they mean by QoS?  Is it IntServ, DiffServ, PVCs, the law of
averages or something else?  I've had to deploy it on a campus network
and in doing so it seems like I've tread into territory where few if
any big networks are to be found.  Nortel apparently removed DiffServ
capability for their "ISP customers" from one of their VoIP product
offerings specifically because the customers didn't want it.  My
impression is that DiffServ is not used by those types of networks you
mentioned, but I'd be interested to hear that I'm mistaken.

> backbone is "better than Best-Effort."  Ok, maybe they aren't
> "the Internet."  Internet2 gave up on premium QOS and deployed
> "less-than Best Effort" scavenger class.  Ok, may they aren't
> "the Internet" either.

Scavenger is not currently enabled on Abielene.  In fact, no QoS
mechanisms are.

> On the other hand, those same QOS tools are very useful to the network
> engineer for managing all sorts of network problems such as DOS
> attacks and disaster recovery as well as more efficiently using all
> the available network paths.

In my experience that is easier said than done.  However, you remind
me of what I think is what most who say they want QoS are really after.
DoS protection.  By focusing on DoS mitigation instead of trying to
provide service differentiation, things begin to make more sense and
actually become much more practical and deployable.

John