Dear Harmen,
   
      My question to service providers are 
  really that, to the
  service providers -- these may include some of the other target 
  
  markets you mentioned.  802.4 was a great technology that 
  
  no one used. 802.5, while IEEE stds, never 
  achieved broad
  interoperability in the industry and did get displaced w/ 
  10BASE-T.  
  FDDI was a great backbone technology that actually got used, until 
  Fast Ethernet switches displaced it.  All of these technology wanted 
  to be the dominant technology that Ethernet is today once 
  it grew up, 
  but it did not.
   
      I could say the same thing about RPR.  It could 
  take over the
  future networking as the preferred standard 
  everywhere; then again, 
  it may not.  RPR is great technology 
  for packet-on-ring, coat-tailing
  off of successes of SONET for TDM.  So if SONET service ring 
  is
  preferred method for Metro distribution, RPR ring may do the same 
  for
  the packet delivery in Metro, and its extensions as the backbone to 
  
  the Ethernet-First-Mile technology.  All other applications, 
  while
  appropriate and possible, is hard to justify with real numbers.  
  Also,
  I do not want to solve the problem that has been solved (and one 
  of
  the 5 criteria, uniqueness, addresses this as well).  We ought to 
  
  optimize RPR for the clear application(s) 
  we used to justify it.  
   
      At this point, I have NO vested interest in 
  influencing the
  standard to fit any implementation.  I hope you and readers take 
  my
  opinion as it reads -- do not optimize the standard for <~5% of the 
  
  market, if it is at the risk of higher 
  cost(complexity, interoperability,
  etc, etc) or scalability.
   
      regards,
   
  Yong.
  ============================================
Yongbum "Yong" 
  Kim      Direct (408)922-7502
Technical 
  Director      Mobile (408)887-1058
3151 Zanker 
  Road        Fax    
  (408)922-7530
San Jose, CA 95134      
  Main   
  (408)501-7800
ybkim@xxxxxxxxxxxx      
  www.broadcom.com
============================================
  
  
  
  Dear Yong
   
  If you only ask service providers whether they 
  would like to support lower speed rings, you not really ask the market that I 
  addressed in my mail. That market has very much to do with communications, but 
  it is not the target of service prioviders. It is the broad market of 
  future multimedia communications mainly in facilities outside the area of 
  network operators and service providers. It is complementory to 802.3 
  networks, it is the world that previously was addressed by 802.4, 802.5, and 
  FDDI. I do not really understand why that market would not be of interest to 
  IEEE 802.17. Why should those areas live outside the standard, when they 
  perfectly fit to resilience and QoS. New standard neccessary?
   
  Additionally addressed market:
  rings and backbone rings for small offices, 
  hotels, major stores, small business centers, hospitals, companies, campus 
  areas, manufactury plants, industrial plants, small public access areas, 
  ships, airplaines, cars, interconnection of base stations of wireless 
  networks, etc., etc.
   
  Best regards
  Harmen
   
   
  Yongbum Kim wrote:
   
  
   
  
 Dear Harmen,
  
  
     Related to the on-going preemption discussions 
  and how
 high priority, low-latency & jitter is handled, I agree 
  
 that high speed RPR ring does not need preemption, but 
  the
 lower speed one does.
  
     I 
  would like to go back to "broad market potential" 
 requirements, and 
  would like to hear from the Service Provider
 community on this 
  subject.  
      How many of the rings in the 
  metro that already has OC3 
      ~ OC12 rings in 
  a SONET infrastructure will be retrofitted 
      
  w/ RPR for packet services?  
  
     My 
  assumption in this had been that if a vendor installs new 
 equipment, 
  it would be the latest and fastest available box, 
  because
 installation and upgrade cost out-weigh box cost.  So 
  the percentage
 of the retrofit market is relatively minimal.  If 
  this is the case, 
 lower speed MAC behavior could live outside of the 
  standard.  If this
 is not the case, then we must define a single 
  preemption behavior
 for all speeds of operation (again the second if, 
  if the group
 wants to entertain the objective of supporting this high 
  priority
 low latency & jitter class). 
  
  
     Would someone from the Service Provider community 
  provide some 
 feedback on this retrofit market?
  
  
 regards,
  
 Yong.
  
   
   ============================================
 Yongbum 
  "Yong" Kim      Direct 
  (408)922-7502
 Technical Director      Mobile 
  (408)887-1058
 3151 Zanker 
  Road        Fax    
  (408)922-7530
 San Jose, CA 95134      
  Main   (408)501-7800
 ybkim@xxxxxxxxxxxx      www.broadcom.com ============================================ 
  ------------------------------------------------------------------
Prof.Dr. 
  Harmen R. van As       Institute of 
  Communication Networks
Head of 
  Institute                      
  Vienna University of Technology
Tel  
  +43-1-58801-38800           
  Favoritenstrasse 9/388
Fax  
  +43-1-58801-38898          A-1040 
  Vienna, Austria
http://www.ikn.tuwien.ac.at      
  email: Harmen.R.van-As@xxxxxxxxxxxx
------------------------------------------------------------------