RE: IP QoS issues

["Constantine Protopapas" <wiztech at cmpnetmail.com>]

> > Depends always on the size of the ATM switch. Most switches
> that are used on
> > the backbone (eg. Newbridge 36190 Core Services Switch) goes up
> to a maximum
> > 2.000.000 VPCs and VCCs per switch. Generally, high-capacity
> ATM switches
> > have adequate capacity.
>
> First, it's extraordinarily unlikely that you'll see individual ATM VC's,
> one per "QoS Flow" (whatever that means to you) because of the inherit
> unscalability of that solution on "the backbone."  I don't know where
> you got the notion that a Newbridge 36190 is representative of what
> gets used on the Internet "backbone" today; I know for UUNET and other
> large backbone operators, this isn't the case.
>
> However, the number of VC's isn't the problem.  This is the same
> misconception
> that people have regarding the size of the routing table causing
> the next Internet apocolypse; it not the SIZE but the CHURN RATE that will
> kill you first.  The thing to worry about is the call setup rate in
> the ATM switches, not the number of VCs it supports.
>
> I now await the inevitable flood of bounced delivery
> notifications :-)  Should
> be more interesting than reading about the IANA cabal.

The 36190 is a Core Switch (meaning you'll probably find it on major
telcos). I know that the Internet backbone is much more limited in capacity
in terms of SVCs. I agree that the "CHURN rate" is the major thing to look
when talking about speed and possible bottlenecks.

Constantine Protopapas
e-mail: wiztech at cmpnetmail.com
	  wiztech at hol.gr

"...i've seen the future;it's digital..."