A Method of Bandwidth Dimensioning and Management Using Flow Statistics

Ryoichi KAWAHARA  Keisuke ISHIBASHI  Takuya ASAKA  Shuichi SUMITA  Takeo ABE  

Publication
IEICE TRANSACTIONS on Communications   Vol.E88-B   No.2   pp.643-653
Publication Date: 2005/02/01
Online ISSN: 
DOI: 10.1093/ietcom/e88-b.2.643
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Network Management/Operation
Keyword: 
TCP performance,  bandwidth dimensioning and management,  number of active flows,  

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Summary: 
We develop a method of dimensioning and managing the bandwidth of a link on which TCP flows from access links are aggregated. To do this, we extend the application of the processor-sharing queue model to TCP performance evaluation by using flow statistics. To handle various factors that affect actual TCP behavior, such as round-trip time, window-size, and restrictions other than access-link bandwidth, we extend the model by replacing the access-link bandwidth with the actual file-transfer speed of a flow when the aggregation link is not congested. We only use the number of active flows and the link utilization to estimate the file-transfer speed. Unlike previous studies, the extended model based on the actual transfer speed does not require any assumptions/predeterminations about file-size, packet-size, and round-trip times, etc. Using the extended model, we predict the TCP performance when the link utilization increases. We also show a method of dimensioning the bandwidth needed to maintain TCP performance. We show the effectiveness of our method through simulation analysis.