T CP (T CP T hr oughput Gu ar ant ee u sing P acket Buffering ), {schoi, ckim }@popeye.snu.ac.kr (Differentiated Services ) T CP (flow ).. T CP.. T CP.. RT T. A bs tract T his paper deals w ith th e T CP b andw idth guarantee problem in a differentiated serv ices (Diffserv ) n et w ork. T he Diffserv assur ed service differ entiates pack et dr op probabilities to gu arantee the promised ban dw idth ev en un der n etw ork con gestion. H ow ev er a token buffer m arker fails to sh ow adequ ate performance becau se T CP g en erates packet s accordin g to the unique T CP con gestion control m echanism. W e propose a m arker that u ses a dat a buffer a s w ell as a t oken buffer. T h e m arker w ith a data buffer w ork s w ell w ith th e as sured service m echanism becau se it sm ooth s T CP traffic. W e show ed th at th e m arker w ith a dat a buffer achiev es the targ et thr ou ghput better th an a m arker w ith a token buffer only. W e also show ed that the optim al buffer size is pr oportional to reserv ed thr ou ghput and RT T. - 1 -
1. (QoS : Quality of Service). QoS (Integrated Serv ice)[1]. RSVP (Resource Reserv ation Setup Protocol)[2] (Signalin g ).. [3, 4]. (Differentiated Services ).. DS (Differentiated Services ) (codepoint ) DS 8, [3]. (Premium Service)[5] (A ssured Service )[6]... [6, 7, 8, 9, 10, 11, 12, 13]. [3, 4, 5, 6]. (boun dary )., (ag greg ated). (m eter ). IN OUT. (m arker ) IP DS IN/ OUT, DS.. (Leaky Bu cket ) T SW (T ime Slidin g W in dow )[6], ET SW (Enhanced T SW )[13]. DS - 2 -
RIO (RED w ith IN an d OUT )[6], ERED (Enhanced RED )[7], (r, RT T )- [13], DRIO (Dynamic RIO)[13]. OUT IN. T CP [7, 8, 9, 13, 14]. T CP (Linear Increa se Multiplicativ e Decrease) (con gestion w in dow ).. OUT. T CP. T CP [7, 8, 10, 13].. T CP T CP. T CP. T CP T CP T CP. T CP. T CP. T CP. (sm oothin g ) T CP.. T CP RT T [15] T CP. T CP.. T CP., RT T. RT T.. 2, T CP. 3. 4 T CP - 3 -
,. 5., RT T. 6. - 4 -
2.... [7, 8, 9, 13]. i r i, C, n. C n i = 1 r i. ( C - n i = 1 r i )., i t i. t i = r i + ( C - n n k = 1 r k ) (1)..,... t i = r i n k = 1 r k C (2) 2.1 T CP T SW RIO T CP [7, 8, 9, 13, 14]. T CP RT T,. T CP. - 5 -
T CP. T CP 1. T CP OUT. T CP,.... 1. T CP T CP. ack (ack - compression ) [16] T CP.. T CP. T CP.. T CP. IN IN.. - 6 -
3. T CP T CP. T CP [7, 8, 10] T CP [8, 13]. F en g [7] (timed tran smission ) T CP. ack., IN..,.. IN IN. F eng [10] IN. IN. T CP T CP. IN OUT,. IN/ OUT. OUT OUT, IN IN. Yeom [8] OUT. T CP OUT OUT.,. Yeom [8]. T CP [15] T CP. - 7 -
.,. RIO,. Rin [13] T SW ET SW (Enh anced T SW ) RIO [6] (r, RT T )-, DRIO (Dyn amic RIO). T SW T CP IN. Rin IN, ET SW. (r, RT T )- DRIO RIO RT T T CP. RIO RT T T CP. (r, RT T )- RT T. DRIO OUT (history list ), (hit ratio) OUT. (r, RT T )- DRIO. - 8 -
4.. T CP,. n s [17]. RIO n s. T CP - Reno. 2.. [8, 9, 13, 15] 2. R0 R1. R0, R 1 10Mbps. R0 R 1. ( * RT T ). IN OUT, OUT. RIO 100. RIO IN 20/ 80/ 0.02 1), OUT 20/ 50/ 0.1. FT P. 1) min t h / max t h / max p - 9 -
4.1., IN. OUT. IN IN. 3. T CP T CP. 1 2 6 T CP 6 T CP. 1Mbps, 10Mbps. 3 T CP. T CP. T CP. T CP ack [16]. ack T CP. T CP RT T ack. T CP - 10 -
,. 4.2... IN. OUT. 4. 3 T CP 4 1 3 T CP.. T CP. T CP. ack. T CP. IN. A g garw al [18] T CP (pacin g ). - 11 -
T CP. T CP. T CP - Ren o. [18] T CP T CP - Ren o. T CP. IN. T CP.. T CP. IN,. T CP RT T [15], T CP.. - 12 -
5..,..,, RT T,.. 5.1 1 3. IN OUT. 1 1Mbp s IN 4Mbps 1.33Mbps. IN,. 1. ( : Mbp s ) IN IN 0 1.13496 0.8004 1.1644 0.93712 1 1.07496 0.7972 1.18432 0.94576 2 1.04464 0.7924 1.21944 0.94704 3 1.10248 0.80248 1.17464 0.93864 4 1.11256 0.8112 1.2144 0.9628 5 1.11856 0.81496 1.144 0.93864 6 0.54408 0.0 0.43016 0.0 7 0.5676 0.0 0.52216 0.0 8 0.5192 0.0 0.48976 0.0 9 0.6328 0.0 0.48584 0.0 10 0.55616 0.0 0.48024 0.0 11 0.5684 0.0 0.46776 0.0-13 -
. 1. 5. 5 IN, IN OUT. 5. 5. IN 1Mbp s, OUT. IN T CP,.. 5.2. 2 8 T CP 2 T CP 8 2Mbps, 1Mbps, 0.5Mbp s, 0.1Mbps. 2-14 -
7.2Mbps, 12Mbp s. 6. 6.,.... (.),.. 0.1Mbps IN.... - 15 -
,. 2 12, 8, 6Mbps. 7.2Mbp s 60, 90, 120%. 7 2Mbp s. (60%, 90% ), (120% )., IN IN. IN. 7. 5.3 RT T RT T T CP. 3 8 T CP 8 T CP. RT T 10, 20, 40, 80m s. 1Mbps, 14Mbp s. 8 3. RT T. T CP RT T [15]. RT T., RT T - 16 -
. 8. RT T - 17 -
6. T CP.. IN T CP, RT T T CP.,, RT T,. RT T. T CP..... - 18 -
[1] R. Braden, D. Clark, S. Shenker, "Integrated Services in the Intern et Architecture: An Ov erview," RF C 1633, Jun., 1994. [2] L. Zhan g, S. Deerin g, D. E strin, S. Sh enker, D. Zappala, "RSVP : A New Resource ReSerV ation Protocol," T ran saction on N etw orking, Sep., 1993. [3] S. Blake, D. Black, M. Carlson, E. Davies, Z. W an g, W eis s, W., "An A rchitecture for Differentiated Services," RF C 2475, Dec., 1998. [4] X. Xiao, L. Ni, "Internet QoS : the Big Picture," M ar./ Apr., IEEE Netw ork. [5] K. Nichols, V. Jacob son, L. Zhang, "A T w o- bit Differentiated Services Architecture for the Internet," Internet Draft, Dec., 1997. [6] D. Clark, W. F ang, "Explicit Allocation of Best Effort Deliv ery S ervice," T r an saction s on Netw orking, Aug., 1998. [7] W. F en g, D. Kan dlur, D. Sah a, K. Shin, "Under stan ding an d Improving T CP Perform an ce ov er N etw ork s w ith Minimum Rate Gu arantees," T ran saction s on Netw orking, A pr., 1999. [8] I. Yeom, A. Reddy, "Realizing throu ghput guarantees in a differentiated services netw ork," ICM CS '99. [9] J. Iban ez, K. Nichols, "Pr elim inary Sim ulation Ev aluation of an A s sur ed S ervice," Int ernet Draft, Au g., 1998. [10] W. F en g, D. Kandlur, D. Saha, K. Shin, A daptiv e Pack et M arkin g for Providin g Differentiated Services in the Intern et," ICNP '98. [11] M. M ay, J. Bolot, A. Jean - M arie, C. Diot, "Simple Perform ance M odels of Differentiated Services Schem es for the Internet," INF OCOM '99. [12] S. Sahu. D. T ow sley, J. Kurose, "A Qu antitativ e Stu dy of Differentiated Services for the Internet," GLOBECOM '99. [13] W. Lin, R. Zh eng, J. C. H ou, "H ow to M ak e A ssured Serv ices M ore A ssured," ICNP '99. [14] N. Seddigh, B. Nan dy, P. Pieda, "Ban dw idth A ssurance Is sues for T CP flow s in a Differentiated Services Netw ork," GLOBE COM '99. [15] J. Padhy e, V. F iroiu, D. T ow sley, J. Kurose, "M odelin g T CP throu ghput : A simple m odel and it s empirical v alidation," SIGCOMM '98. [16] L. Zh ang, S. Sh enk er, D. Clark, "Ob serv ation s on the Dynamics of a Cong estion Control Alg orithm : T he Effect s of T w o- W ay T raffic," SIGCOMM '91. [17] U CB, LBNL, VINT N etw ork Simulator - n s http :// w w w - m ash.cs.berkeley.edu/ n s/ n s.html [18] A. A gg arw al, S. Sav age, T. An der son, "Under stan ding the Perform ance of T CP Pacin g," INF OCOM ' 2000. - 19 -