Dynamic bandwidth allocation in multi-class IP networks using utility functions.
Veselin Rakočević · Queen Mary Research Online (Queen Mary University of London) · 2002
The Internet needs to evolve from a single-service data network into the multiservice intelligent IP-based network capable of satisfying diverse performance requirements.The way network resources, primarily bandwidth, will be allocated in the future network presents a very important research issue.Bandwidth allocation should be simple to implement and optimally designed to maximise the network performance.The majority of the research on bandwidth allocation in the Internet deals with the problem of bandwidth allocation in a single-service environment, in which the entire Internet traffic is treated as data transfer.This Thesis presents Dynamic Bandwidth Partitioning, a new bandwidth allocation scheme for the multiservice Internet.In this scheme, the link bandwidth is partitioned in order to isolate the different traffic types and at the same time maximise the performance.The partitioning is dynamic; it changes according to a simple 'additive increase, additive decrease' linear control algorithm.The information about the change in the partitioning comes from the measured level of network performance.In other words, the Dynamic Bandwidth Partitioning scheme is user-oriented, adaptive and reasonably simple to implement.The contribution of this work is in the introduction of the new bandwidth allocation scheme, and in the metric that was used for the network performance evaluation.This new metric is called connection utility.Connection utility is the assessment of the quality of service level which a user of an Internet application derives from the network performance.It is measured by using utility functions.The significant novelty of this work is in including nonconcave utility functions for real-time traffic classes.Based on the information about the utility of the active traffic on the link, a decision about changes in the bandwidth allocation is made.This Thesis presents the Dynamic Bandwidth Partitioning scheme in detail, including the partitioning algorithm and different utility functions that were used.Through extensive simulation the scheme is compared to several other bandwidth allocation concepts.The results presented here clearly show the network environments in which implementation of the new scheme can prove to be very efficient.Furthermore, the Thesis presents the guidelines for the implementation of the scheme in the MPLS-capable networks.