QoS/CoS interest

Thu May 22 13:49:23 UTC 1997

Paul:

QoS/CoS Heresies:

I have enjoyed your articles in ISOC journal on QoS.  As you know we are 
actively looking at QoS/CoS issues here in Canada with respect to our next 
generation Internet program - CA*net II.

However, I always alike to be a bit contrarian and point out that QoS or 
Multicast may never be needed because of the explosive growth of fiber 
bandwidth.  I believe, in the future, it will be a lot easier and cheaper to 
deploy bandwidth rather than manage complex router/switch technology to 
support QoS/CoS.

The other issue that several studies have shown that the Internet congestion 
suffered by most users is generally not due to backbone congestion, but 
inadequate server facilities.  So a network QoS/Cos will not solve congestion 
problems as has been promised to many corporations through "business class" 
Internet service offerings.

I believe that large Sonet pipes, and very shortly, all optical networks will 
provide so much bandwidth on backbone networks that the need for QoS/CoS on 
the backbone will be irrelevant.

The other major argument for Qos/CoS is to prevent abuse of the commons from 
"power users".  But usage charging either by access bandwidth, or average 
load will be far more effective mechanism to prohibit abuse of the commons. 

Alreasy we are seeing several OC192 networks being deployed in Canada and the 
US.  Most of these networks have the capacity to increase their bandwidth 
with WDM and DWDM another 100 fold or 1000 fold.  As well, here in Canada, we 
have a couple of companies that are deploying SONET to the desktop solutions 
- Positron, Skystone, JDS, etc.  The nice thing about these SONET to the 
desktop solution is that they emulate traditional Ethernet and Fast Ethernet 
interfaces. I believe Nortel and Ciena are also building ADM's that will act 
more like SONET channel switches rather than traditional ADM mux's.

I have heard rumours that Ciena and another couple WDM companies will be 
delivering the first commercial all optical switches within a year or so.  
These switches will initially only do channel switching, but even with that 
the throughput capacity of these switches will be in the "femtabit" range. 
The fastest ATM switch will pale in comparison.

The challenge for the routing and switching companies will not be to 
implement QoS/CoS, but to build fast enough switches and routers to keep up 
with this fire hose of data.  This will have a major implication on network 
design - the concept of the telco intelligent network is dead at these data 
volumes.  Network intelligence must move to the edge.

It for these reason, the CA*net 2 architecture features no core routers.  All 
of the routing functions and control of the network have moved to the edge. 
Perversely, however, this ATM (or SONET) architecture has necessitated that 
we buy more routers than ever!!! Now we need separate tunnel servers, Mbone 
PIM servers, etc that are independent of the main edge router, because of the 
significant load that edge router has to handle in this routerless core 
network.!!

For more information please see the CA*net II web site at:

http://www.canarie.ca/c2

Bill

--- On Wed, 21 May 1997 14:04:35 -0400  Paul Ferguson <pferguso at cisco.com> 
wrote:
> I'd like to get a feel for what the temperature level
> is in the ISP community for this issue -- I have a vested
> [personal] interest in understanding what your understanding
> & implementation plans are in this arena.
> 
> Please send your thoughts, requirements, bitches, etc., to
> me personally, or preferably, to the NANOG list; it is a
> greater audience than myself that wishes to understand these
> issues.
> 
> Thanks!
> 
> - paul
> 
> 
> 

---------------End of Original Message-----------------

-------------------------------------
Bill St. Arnaud           CANARIE Inc
Director Network Projects 470-410 Laurier Ave W
Tel: +1 613 660-3497      Ottawa          
     199.212.24.5         Canada  
FAX: +1 613 660-3806      K1P 6H5            
bill.st.arnaud at canarie.ca  http://www.canarie.ca/bstarn  