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@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@canarie.ca http://www.canarie.ca/bstarn