The scheme to implement Rate Adaptive Shaper for Differentiated Service Network - srRAS and G-srRAS -

  • Park, Chun-Kwan (Division of Electronics and Communication Engineering, Mokpo National Maritime University) ;
  • Kim, Kab-Ki (Division of Electronics and Communication Engineering, Mokpo National Maritime University)
  • Published : 2003.09.01


This paper has addressed the implementation of the single rate Rate Adaptive Shaper(srRAS) described in RFC2963. This shaper has been proposed to use at the ingress of differentiated services networks providing Assured Forwarding Per Hop Behavior (AFPHB). srRAS is typically used in conjunction with single rate Three Color Marker(srTCM) described in RFC2697. srRAS itself is the tail-drop FIFO that is drained at a variable rate, and srTCM is the marker with metering function. G-srRAS is the same as srRAS except that RAS receives the green token state information from the downstream srTCM to avoid delaying a packet in RAS although there are sufficient tokens available to color the packet green. In this paper, we have addressed the algorithm and the architecture of srRAS, and the scheme to implement srRAS using VHDL(Very high-speed integrated circuit Hardware Description Language) and its related tools.


Single rate Rate Adaptive Shaper(srRAS);srTCM(single rate Three Color Marker);Assured Forwarding Per Hop Behavior (AF PHB);Differentiated Service CodePoint(DSCP)


  1. J. S. Hong, 'Design of an ATM shaping multiplexer algorithm and architecture,' Ph.D. dissertation, Electrical Engineering Department, Polytechnic University, Brooklyn, NY, Jan 1997
  2. J. Heinanen, F. Baker, W. Weiss, and J. Wroclawski, 'Assured Forwarding PHB Group', RFC2597, June 1999
  3. Srinvas Vegesna, 'IP Quality of Service', Cisco Press, 2001
  4. P.-C. Chen, 'The design of a timing processor for ATM traffic shaper,' Masters thesis, Polytechnic University, Brooklyn, NY, Jul.1995
  5. O. Bonaventure and S. De Cnodder, 'A Rate Adaptive ShapeI for Differentiated Services', RFC2963, October 2000
  6. Stocia I., Shenker S. and H. Zhang, 'Core-stateless fair queueing: achieving approximately fair bandwidth allocations in high-speed networks', ACM SIGCOMM98, pp. 118-130, September 1998
  7. H. Jonathan Chao and Xiaolei Guo, 'Quality of Service Control in High-Speed Networks', John Wiley&Sons, 2002
  8. Heinanen J. and R. Guerin, 'A Single Rate Three Color Marker', RFC2697, September 1999
  9. Heinanen J. and R. Guerin, 'A Two Rate Three Color Marker', RFC2698, September 1999
  10. Greville Armitage, 'Quality of Service in IP Networks:foundation for a Multi-Service Internet', MTP, April 2000