000-985/00/3(08)55-06 00 Journal of Software Vol3, No8, (,00084) E-mal: yong98@malstsnghuaeducn http://netlabcstsnghuaeducn :,,, (proportonal farness schedulng, PFS), QoS, : ; ;QoS; : TP393 : A,,,,, ( ),,,,, [,] [3~5],, ; [6], IP,, IP ; [7] (classcal constraned optmsaton) (genetc algorthm),, (proportonal farness schedulng, PFS), (QoS), PFS 3 4 : 00-06-0; : 00-0-4 : (900400) : (975 ),,,,,, ; (953 ),,,,,,
56 Journal of Software 00,3(8) 5 Internet, (relatve dfferentated servces) [8], (servce classes),, ( ) ( )(<<N) ( ),,,, Internet,,Internet,, [9], (proportonal farness prncple),, : q / q c / c,,,, N, () c < c < < c N,,,, dˆ, F dˆ / δ dˆ / δ,,,, N, () { } δ (delay dfferentaton parameters, Ps),, δ δ > > δ 0 > N >, lˆ, F lˆ / ˆ σ l / σ,, N, σ (loss rate dfferentaton parameters, LPs), σ > σ > > σ N > 0 Parekh Gallager [0],,,, ;, [,], 0,,,, M, ( ) c,c, n [ t, L t t, n n R [ R [ L ; [ t R [ ] [] t Q [], t t, t, R q (3)
: 57 n [] 0 [] 0 0 R, 0, n R R [] 0 Q [ 0 ] 0, [ 0 ] 0 L n n n n R [ s, [ s,, R [ s, R [ m] s > t, [ s, 0, R [ s, [ s,,, t ( t) t l Q[ R l t t d[ n d[ mn{ : 0 and R [, R [, t + ]} (6), (FIFO), d[ t () n ( ) b, R b, n n t s t R [ s +, b t s, ( b x) σ + ρx, R ( σ, ρ ) ~ [9] ~, d / δ d / δ d, d, s ( ),, max ~ d δd, ( ()) max ~ ( ) b, d δd P ( ), P () t 0, b t d t s t Q [ s] 0 R [ s +, P ( t s), P ( ), P ( t s) [ s +,, t,s t, 0, [ R n ( ) b, P ( ) B lˆ P (t ) b( t)( l ˆ ) B, t 0, (8) l(t) lˆ B B max{ b ( t B Btotal, B, B total ~ ~ M l l ( b () t ( t) B σ b () t P ( ) [ ] M P total ) n () [, R [ 0, n [ 0, t m s [, 0 (4) L R (5) f max ( ), f t ( ) max max 0 t d n R [] ( ) d ( ) t b, P ( ) ~ )( l ) P ( t), t 0} σ, (9) 3 PFS M,,,M M R (7)
58 Journal of Software 00,3(8), (9),, P ( ), t 0,, Q [ 0,,,M () t, τ t t, τ t max s : s t and Q [ s] 0,,, M (0) ( ) { } Z (), t R [ () t +, Z ( t), Z () t s Q τ () mn { R [ τ ( t) +, s] + P ( t s) } : τ () t s t [ s] 0 (PFS) ()(deadlne), t t, 0 Z ( ) 3 (9),,,,u M n, ( Q [ ] + [, c u u R u]) u Z ( t; u) n { t : t u and Z ( t; u ) n } () mn, (3) mn { R [ τ ( u) +, s] + P ( t s) } (4) : τ ( u) s u [ s] 0 s Q ( u; u) Z (u ) (4), Z ( t; u) ( t), Z 4 Z u 4 0 0Mbps 0Mbps 0Mbps PFS ns- [3], PFS 0,, 0Mbps 3, 3 4 0Mbps Fg Topology n test 3 0, 0,, 3, 3 00K 3 0Mbps 4 4 3, (audo) 0ms 60, (vdeo) 33ms 8K, 4K, FTP PFS, 5, 0, 00
: 59 Table Traffcs n the test Class I Flow type Assgned rate (bps) Interval Packet length (Bytes) Input 0 Audo 64K 0ms 60 0 Vdeo M 33ms 8K On/Off 5M 5s 4K Posson M None 4K FTP 5M None 4K I,,,,,PFS ON-OFF, ON-OFF, PFS,,, 5 elay (ms) 30 5 0 5 0 5 0 5000 0000 5000 30000 35000 class 0 class class Tme (ms) Fg Traffc delay dstrbuton n servce classes, (QoS), :() ;(), ;(3),,, References: [] Cruz, RL A calculus for network delay, part I: network elements n solaton IEEE Transactons on Informaton Theory, 99,37():4~3 [] Cruz, RL A calculus for network delay, part II: network analyss IEEE Transactons on Informaton Theory, 99,37():3~4 [3] Kurose, J On computng per-sesson performance bounds n hgh-speed mult-hop computer networks In: Proceedngs of the ACM Sgmetrcs and Performance 9 New York, 99 8~34 [4] Yaron, O, Sd, M Performance and stablty of communcaton networks va robust exponental bounds IEEE/ACM Transactons on Networkng, 993,(3):37~385 [5] Chang, CS Stablty, queue length, and delay of determnstc and stochastc queueng networks IEEE Transactons on Automatc Control, 994,39(5):93~93 [6] Hurley, P, Boudec, JL A proposal for an asymmetrc best-effort servce In: Proceedngs of the IWQOS 99 London, 999 9~3
50 Journal of Software 00,3(8) [7] Ptslldes, A, Stylanou, G, et al Bandwdth allocaton for vrtual paths (BAVP): nvestgaton of performance of classcal constraned and genetc algorthm based optmsaton technques In: Proceedngs of the INFOCOM 000 Tel Avv, 000 379~387 [8] ovrols, C, Stlads, Relatve dfferentated servces n the Internet: ssues and mechansms In: Proceedngs of the ACM SIGMETRICS 99 Atlata, 999 04~05 [9] Jang, Y Ln, C, Wu, J Integrated performance evaluatng crtera for network traffc control In: Proceedngs of the IEEE Symposum on Computers and Communcatons 00 Tunsa: IEEE Communcatons Socety Press, 00 [0] Parekh, AK, Gallager, RG A generalzed processor sharng approach to flow control n ntegrated servces networks: the sngle-node case IEEE/ACM Transactons on Networkng, 993,(3):344~357 [] Le, J-Y, et al Connectonless data servce n an ATM-Based customer premses network Computer Networks and ISN Systems, 994,6():409~44 [] Agrawal, R, Raan, R Performance bonds for flow control protocols IEEE/ACM Transactons on Networkng, 999,7(3):30~33 [3] Ucb/lbnl/vnt network smulator-ns (verson ) 00 A Packet Schedulng Strategy for Multple Performance Obects JIANG Yong, WU Jan-png (epartment of Computer Scence and Technology, Tsnghua Unversty, Beng 00084, Chna) E-mal: yong98@malstsnghuaeducn http://netlabcstsnghuaeducn Abstract: The desgn of packet schedulng strategy and algorthm s one of the most mportant ssues for the hgh-speed packet-swtched networks Because the packet schedulng strategy has multple performance obects, how to reach multple obects smultaneously s a dffcult problem Based on the proportonal farness prncple, a proportonal farness schedulng (PFS) strategy n packet-swtched networks s provded The PFS ntegrates several obects, such as network performance, user s QoS requrement and system farness And the proposed strategy s analyzed and proved n detal Moreover, the proportonal farness schedulng strategy can be appled to desgn and mprove the packet schedulng strategy and algorthms n packet-swtched networks Key words: proportonal farness prncple; packet schedulng; QoS; farness Receved June 0, 00; accepted January 4, 00 Supported by the Natonal Natural Scence Foundaton of Chna under Grant No900400