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D27: TE and TMCM - Status and Plans -. M. Köhn, D. Sass, C. M. Gauger Institute of Communication Networks and Computer Engineering Universität Stuttgart {koehn, sass, gauger}@ikr.uni-stuttgart.de. Overview. TE for multipoint connections, network-based VPNs Status: modeling, tool, …
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D27: TE and TMCM- Status and Plans - M. Köhn, D. Sass, C. M. GaugerInstitute of Communication Networks and Computer EngineeringUniversität Stuttgart{koehn, sass, gauger}@ikr.uni-stuttgart.de
Overview • TE for multipoint connections, network-based VPNs • Status: modeling, tool, … • Planned work • Effective bandwidth for network dimensioning of packet-level demands • Status: analysis of different methods (complexity, precision, …), tools, first results for our traces • Planned work • Traffic measurement, characterization, modeling • Status: tool extensions, … • Planned work • Modeling and Performance Evaluation of iSCSI SANs over TCP/IP MANs and WANs
Scenario • Multi layer network (here SDH/WDM) • Dynamic multi point connections, VPNs Traffic engineering strategy? new multipoint connection electrical Layer optical Layer
Modeling of VPNs • Topology description of a VPN • Set of nodes • Set of links, bandwidth of the links • Assumptions • Dedicated Resources VPN (acc. to TF VPN, WP4) • Full mesh topology • All links same bandwidth, but not all VPNs same bandwidth • To be modeled • Arrival and holding time of a VPN (as p2p) • Distribution of VPN bandwidth (as p2p) • Participation of the nodes in a VPN
Modeling of VPNs • Target • Simple and parsimonious set of parameters • Simple to implement in simulations • Concept adopted from population model based traffic models (i.e. Cost Reference Networks) • Each node represents a number of users/hosts hi • Same probability to participate in a VPN for all hosts • Total network traffic given • Probability pv for a certain set of nodes v
Impact on network dimensioning • Until now • Network dimensioning for point-to-point connections • Offered traffic for each node pair required • Idea: Map VPN traffic to traffic between node pairs and reuse network dimensioning schemes • Derive offered traffic for a node pair Ai,j • Find all possible VPNs with node i and j • Sum the offered traffic of the found VPNs
Path selection strategy • High computation effort for parallel schemes(e.g. multi commodity flow problem, …)not feasible in real time • Sequential approaches • Decompose VPN to set of point-to-point connections • Reuse well known integrated multi layer schemes • Degrees of freedom • Ordering of p2p connections • state independent (distance, by source node, …) • state dependent (avail. paths, , …) • Number of retries • Scheme for p2p path selection
Conclusion • New contributions • Model for multi point connections • Dimensioning approach based on common schemes • Path selection strategies for multi layer networks • Tool support for dimensioning and evaluation • Planned for D27 • Problem modeling • Description of strategies • Several case studies
Effective bandwidth for network dimensioning of packet-level demands
Effective Bandwidth Status • Allows the transition from packet-level traffic descriptions to circuit-level used for transport network dimensioning and TE • Several effective bandwidth methods exist • Kelly with diff. hypotheses (LBA, MSA); Guerin; … • But only few comparisons exists • Comparison wrt/ • Precision • Complexity • Multi-service suitability (data/voice, Kelly/MSA) • Applicability to traces, models (fBm, FF, M/Pareto) • Bufferless, buffered scenario
Effective Bandwidth • Application studies to UST trace using Kelly’s method with many sources asymptotic
Effective Bandwidth Planned work • Extension to trace characterization for the emerging NOBEL network applications (BB4all) • Study of the multiservice capabilities • Application to dimensioning of different network architectures • Architecture comparison • Comparison of effective bandwidth on a network level (rounding…) • Case studies, e.g. SDH scenario (i.e. fine b/w granularity), WDM scenario (i.e. coarse granularity)
TMCM Status (most recent activities, other: c.f. Paris) • Improvement of trace characterization tool • more flexibility towards multi-service characterization • efficient treatment of large trace files • Enhancement of software for measurement equipment • Defining investigation scenarios for studies withL-Systems • focus on relevant parameters and properties
TMCM Planned • Continuation of measurement activity • for identification of trends • increase trace pool for different studies • Flow/stream characterization • Focus on modeling with L-Systems • flexibel model to bridge gap between packet & connection level • Studies regarding matching requirements • mainly application on different timescales • accuracy & parameter influence • reflecting/influence of aggregation Identify application cases and exploit power of model
Modeling and Performance Evaluation of iSCSI SANs over TCP/IP MANs and WANs c.f. separate slide presentation and report P-WP2-2005-04-11_SANModelingPerformance_UST-IKR.ppt