Impact of Traffic Aggregation on Network Capacity and Quality of Service : Preliminary Results

The impact of traÆc handling mechanisms on network capacity and supporting of Quality of Service (QoS) in the Internet is studied. The emergence of applications with diverse throughput, loss and delay requirements requires a network that is capable of supporting di erent levels of service as opposed to the single best-e ort service that was the foundation of the Internet. As a result the Integrated Services (perow) and Di erentiated Services (Di serv) models have been proposed. The perow model requires resource reservation on a perow basis while the Di serv model requires no explicit reservation of bandwidth for individual ows and instead relies on a set of pre-de ned service types to provide QoS to applications. Flows are grouped into aggregates having the same QoS requirements and the aggregates are handled by the network as a single entity with no ow di erentiation. We refer to this type of handling as semi-aggregate or class-based. The Best-E ort model does not perform any di erentiation and handles all traÆc as a single aggregate. Each of these traÆc handling models can be used to meet service guarantees of di erent traÆc types, the major di erence being in the quantity of network resources that must be provided in each case. The cross-over point at which the three approaches of aggregate traÆc management, semi-aggregate traÆc management and perow traÆc management become equivalent is found. Speci cally, we determine the network capacity required to achieve equivalent levels of performance under these three traÆc management approaches. We use maximum end-to-end delay as the QoS metric and obtain analytic expressions for network capacity based on deterministic network analysis. One key result of this work is that on the basis of capacity requirements, there is no signi cant di erence between semi-aggregate traÆc handling and perow traÆc handling. However Best-E ort handling requires more capacity that may be several orders of magnitude greater than perow handling.

[1]  Gustavo de Veciana,et al.  Bandwidth allocation for multiple qualities of service using generalized processor sharing , 1996, IEEE Trans. Inf. Theory.

[2]  Harrick M. Vin,et al.  Determining end-to-end delay bounds in heterogeneous networks , 1995, Multimedia Systems.

[3]  Scott Shenker,et al.  Supporting real-time applications in an Integrated Services Packet Network: architecture and mechanism , 1992, SIGCOMM '92.

[4]  Edward W. Knightly,et al.  Deterministic delay bounds for VBR video in packet-switching networks: fundamental limits and practical trade-offs , 1996, TNET.

[5]  Gerald Eichler,et al.  Implementing integrated and differentiated services for the Internet with ATM networks: a practical approach , 2000, IEEE Commun. Mag..

[6]  Donald F. Towsley,et al.  Bounds, approximations and applications for a two-queue GPS system , 1996, Proceedings of IEEE INFOCOM '96. Conference on Computer Communications.

[7]  Domenico Ferrari.  Client requirements for real-time communication services , 1990 .

[8]  Jean-Yves Le Boudec,et al.  Application of Network Calculus to Guaranteed Service Networks , 1998, IEEE Trans. Inf. Theory.

[9]  Moshe Sidi,et al.  Stochastically bounded burstiness for communication networks , 1999, IEEE INFOCOM '99. Conference on Computer Communications. Proceedings. Eighteenth Annual Joint Conference of the IEEE Computer and Communications Societies. The Future is Now (Cat. No.99CH36320).

[10]  Scott Shenker,et al.  Is service priority useful in networks? , 1998, SIGMETRICS '98/PERFORMANCE '98.

[11]  Keith W. Ross,et al.  Guaranteeing statistical QoS to regulated traffic: the single node case , 1999, IEEE INFOCOM '99. Conference on Computer Communications. Proceedings. Eighteenth Annual Joint Conference of the IEEE Computer and Communications Societies. The Future is Now (Cat. No.99CH36320).

[12]  K. Kilkki.  Differentiated Services for the Internet , 1999 .

[13]  Donald F. Towsley,et al.  Statistical Analysis of Generalized Processor Sharing Scheduling Discipline , 1995, IEEE J. Sel. Areas Commun..

[14]  Van Jacobson,et al.  Link-sharing and resource management models for packet networks , 1995, TNET.

[15]  Cheng-Shang Chang,et al.  Stability, queue length, and delay of deterministic and stochastic queueing networks , 1994, IEEE Trans. Autom. Control..

[16]  Srinivasan Keshav,et al.  Comparison of rate-based service disciplines , 1991, SIGCOMM '91.

[17]  Abhay Parekh,et al.  A generalized processor sharing approach to flow control in integrated services networks: the single-node case , 1993, TNET.

[18]  F. M. Chiussi,et al.  Implementing fair queueing in ATM switches. I. A practical methodology for the analysis of delay bounds , 1997, GLOBECOM 97. IEEE Global Telecommunications Conference. Conference Record.

[19]  Rene L. Cruz,et al.  A calculus for network delay, Part II: Network analysis , 1991, IEEE Trans. Inf. Theory.

[20]  Scott Shenker,et al.  Analysis and simulation of a fair queueing algorithm , 1989, SIGCOMM '89.

[21]  R. Braden,et al.  Resource Reservation Protocol (rsvp) , 1995 .

[22]  Debasis Mitra,et al.  Design of generalized processor sharing schedulers which statistically multiplex heterogeneous QoS classes , 1999, IEEE INFOCOM '99. Conference on Computer Communications. Proceedings. Eighteenth Annual Joint Conference of the IEEE Computer and Communications Societies. The Future is Now (Cat. No.99CH36320).

[23]  Abdelhakim Hafid,et al.  Cooperative QoS management for multimedia applications , 1997, Proceedings of IEEE International Conference on Multimedia Computing and Systems.

[24]  Zhi-Li Zhang,et al.  Source Time Scale and Optimal Buuer/bandwidth Trade-oo for Heterogeneous Regulated Traac in a Network Node , 1996 .

[25]  Edward W. Knightly,et al.  Inter-class resource sharing using statistical service envelopes , 1999, IEEE INFOCOM '99. Conference on Computer Communications. Proceedings. Eighteenth Annual Joint Conference of the IEEE Computer and Communications Societies. The Future is Now (Cat. No.99CH36320).

[26]  Efficient support of delay and rate guarantees in an internet , 1996, SIGCOMM '96.

[27]  Scott Shenker,et al.  Core-stateless fair queueing: achieving approximately fair bandwidth allocations in high speed networks , 1998, SIGCOMM '98.

[28]  George C. Polyzos,et al.  Scheduling for quality of service guarantees via service curves , 1995, Proceedings of Fourth International Conference on Computer Communications and Networks - IC3N'95.

[29]  P. K. Verma,et al.  The economics of segregated and integrated systems in data communication with geometrically distributed message lengths , 1974, DATACOMM '73.

[30]  Roch Guérin,et al.  Quality-of-Service in Packet Networks: Basic Mechanisms and Directions , 1999, Comput. Networks.

[31]  Hui,et al.  Tra c Characterization and Switch Utilization using a DeterministicBounding Interval Dependent Tra c , 1995 .

[32]  Scott Shenker,et al.  Best-effort versus reservations: a simple comparative analysis , 1998, SIGCOMM '98.

[33]  Rene L. Cruz,et al.  A calculus for network delay, Part I: Network elements in isolation , 1991, IEEE Trans. Inf. Theory.

[34]  Darryl Black.  Building Switched Networks , 1999 .

[35]  Keith W. Ross,et al.  Guaranteeing statistical QoS to regulated traffic: the multiple node case , 1998, Proceedings of the 37th IEEE Conference on Decision and Control (Cat. No.98CH36171).

[36]  Scott Shenker,et al.  Integrated Services in the Internet Architecture : an Overview Status of this Memo , 1994 .

[37]  Patrick Thiran,et al.  A short tutorial on network calculus. I. Fundamental bounds in communication networks , 2000, 2000 IEEE International Symposium on Circuits and Systems. Emerging Technologies for the 21st Century. Proceedings (IEEE Cat No.00CH36353).

[38]  Ion Stoica,et al.  Providing guaranteed services without per flow management , 1999, SIGCOMM '99.

[39]  Moshe Sidi,et al.  Performance and stability of communication networks via robust exponential bounds , 1993, TNET.

[40]  Abhay Parekh,et al.  A generalized processor sharing approach to flow control in integrated services networks: the multiple node case , 1994, TNET.

[41]  G. A. Mack,et al.  Order Statistics (2nd Ed.) , 1983 .

[42]  S. Shenker.  Fundamental Design Issues for the Future Internet , 1995 .

[43]  Domenico Ferrari,et al.  Rate-controlled static-priority queueing , 1993, IEEE INFOCOM '93 The Conference on Computer Communications, Proceedings.

[44]  David D. Clark,et al.  Explicit allocation of best-effort packet delivery service , 1998, TNET.

[45]  Mischa Schwartz,et al.  Broadband integrated networks , 1996 .

[46]  Michel Mandjes,et al.  Delay performance analysis of the new Internet services with guaranteed QoS , 1997, Proc. IEEE.

[47]  Andrea Fumagalli,et al.  A deterministic approach to the end-to-end analysis of packet flows in connection-oriented networks , 1998, TNET.

[48]  Lachlan L. H. Andrew,et al.  Quality of service driven packet scheduling disciplines for real-time applications: looking beyond fairness , 1999, IEEE INFOCOM '99. Conference on Computer Communications. Proceedings. Eighteenth Annual Joint Conference of the IEEE Computer and Communications Societies. The Future is Now (Cat. No.99CH36320).

[49]  Geoff Huston,et al.  Quality of Service: Delivering QoS on the Internet and in Corporate Networks , 1998 .