North American Network Operators Group

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RE: Q:Why router with ATM interface comes out earlier than pure SONET interface?

  • From: Christian Kuhtz
  • Date: Mon Aug 03 23:05:08 1998

> Hmm. How would you assure per-application Quality-of-Service
> without letting
> the network explicitely know about application behaviour, i.e. signalling
> those parameters and establishing some state within network nodes - read:
> connection oriented ? How would you ? Even IP's approaches to this problem
> are stateful.

Clearly define your requirements.  Otherwise this discussion is academic.
Give me a scenario and I'll engineer you an IP QoS traffic engineering

How many "different" application specific behaviors does one need and make
up a manageable quantity of CoS across a service provider network?  I don't
think you'll ever see more than half a dozen or so anytime soon.

How exactly do you sell 64 different classes of service to customers?  "I
would like CoS #57, please." -- "Would you like fries with that, sir?"  How
is Cos #57 different from CoS #56 or #58?

Signaling assumes connection oriented networking.  The question is whether
you really need to "signal" across the core of a network.  Why does the
entire core need to know about everything?

IP QoS is fundamentally different from a traffic engineer point.  You don't
define pipes, like in ATM.  You don't associate QoS characteristics to a
given pipe, because you don't have pipes like in ATM.

You define rates, you define drop policies and queuing policies on a per
<insert the a defineable *packet* characteristic here>.  My point being that
all you ATM QoS bigots need to stop thinking like ATM and forget the idea of
a connection pipe at the transporrt layer, and listen to us IP QoS bigots
:).  Perhaps we actually do have a point, and one doesn't actually need ATM.

Am I making any sense?  I think a Q&A model for this discussion would be
best, especially considering the "bandwidth" limitations of all
participating parties..


Christian Kuhtz, BellSouth Corp., Sr. Network Architect  <[email protected]>
1100 Ashwood Parkway, Atlanta, GA 30338                        <[email protected]>
"Legalize free-enterprise murder: why should governments have all the fun?"
                                                      -- /usr/games/fortune