Washington University in St. Louis Washington University Open Scholarship All Computer Science and Engineering Research Computer Science and Engineering Report Number: WUCSE-2002-26 2002-08-20 Design of Overlay Networks for Internet Multicast - Doctoral Dissertation, August 2002 Yunxi Sherlia Shi Multicast is an efficient ansmissiontr scheme for supporting group communication in networks. Contrasted with unicast, where multiple point-to-point connections must be used to support communications among a group of users, multicast is more efficient because each data packet is replicated in the network – at the branching points leading to distinguished destinations, thus reducing the transmission load on the data sources and traffic load on the network links.o T implement multicast, networks need to incorporate new routing and forwarding mechanisms in addition to the existing are not adequately supported in the current networks. The IP multicast are not adequately... Read complete abstract on page 2. Follow this and additional works at: https://openscholarship.wustl.edu/cse_research Recommended Citation Shi, Yunxi Sherlia, "Design of Overlay Networks for Internet Multicast - Doctoral Dissertation, August 2002" Report Number: WUCSE-2002-26 (2002). All Computer Science and Engineering Research. https://openscholarship.wustl.edu/cse_research/1144 Department of Computer Science & Engineering - Washington University in St. Louis Campus Box 1045 - St. Louis, MO - 63130 - ph: (314) 935-6160. This technical report is available at Washington University Open Scholarship: https://openscholarship.wustl.edu/ cse_research/1144 Design of Overlay Networks for Internet Multicast - Doctoral Dissertation, August 2002 Yunxi Sherlia Shi Complete Abstract: Multicast is an efficient ansmissiontr scheme for supporting group communication in networks. Contrasted with unicast, where multiple point-to-point connections must be used to support communications among a group of users, multicast is more efficient because each data packet is replicated in the network – at the branching points leading to distinguished destinations, thus reducing the transmission load on the data sources and traffic load on the network links.o T implement multicast, networks need to incorporate new routing and forwarding mechanisms in addition to the existing are not adequately supported in the current networks. The IP multicast are not adequately supported in the current networks. The IP multicast solution has serious scaling and deployment limitations, and cannot be easily extended to provide more enhanced data services. Furthermore, and perhaps most importantly, IP multicast has ignored the economic nature of the problem, lacking incentives for service providers to deploy the service in wide area networks. Overlay multicast holds promise for the realization of large scale Internet multicast services. An overlay network is a virtual topology constructed on top of the Internet infrastructure. The concept of overlay networks enables multicast to be deployed as a service network rather than a network primitive mechanism, allowing deployment over heterogeneous networks without the need of universal network support. This dissertation addresses the network design aspects of overlay networks to provide scalable multicast services in the Internet. The resources and the network cost in the context of overlay networks are different from that in conventional networks, presenting new challenges and new problems to solve. Our design goal are the maximization of network utility and improved service quality. As the overall network design problem is extremely complex, we divide the problem into three components: the efficient management of session affictr (multicast routing), the provisioning of overlay network resources (bandwidth dimensioning) and overlay topology optimization (service placement). The combined solution provides a comprehensive procedure for planning and managing an overlay multicast network. We also consider a complementary form of overlay multicast called application-level multicast (ALMI). ALMI allows end systems to directly create an overlay multicast session among themselves. This gives applications the flexibility ot communicate without relying on service provides. The tradeoff is that users do not have direct control on the topology and data paths taken by the session flows and will typically get lower quality of service due to the best effort nature of the Internet environment. ALMI is therefore suitable for sessions of small size or sessions where all members are well connected to the network. Furthermore, the ALMI framework allows us to experiment with application specific components such as data eliabilityr , in order to identify a useful set of communication semantic for enhanced data services. Short Title: Overlay Multicast Networks Shi, D.Sc. 2002 WASHINGTON UNIVERSITY SEVER INSTITUTE OF TECHNOLOGY DEPARTMENT OF COMPUTER SCIENCE DESIGN OF OVERLAY NETWORKS FOR INTERNET MULTICAST by Yunxi Sherlia Shi Prepared under the direction of Professor Jonathan S. Turner A dissertation presented to the Sever Institute of Washington University in partial fulfillment of the requirements for the degree of Doctor of Science August, 2002 Saint Louis, Missouri WASHINGTON UNIVERSITY SEVER INSTITUTE OF TECHNOLOGY DEPARTMENT OF COMPUTER SCIENCE ABSTRACT DESIGN OF OVERLAY NETWORKS FOR INTERNET MULTICAST by Yunxi Sherlia Shi ADVISOR: Professor Jonathan S. Turner August, 2002 Saint Louis, Missouri Multicast is an efficient transmission scheme for supporting group communication in networks. Contrasted with unicast, where multiple point-to-point connections must be used to support communications among a group of users, multicast is more efficient be- cause each data packet is replicated in the network – at the branching points leading to dis- tinguished destinations, thus reducing the transmission load on the data sources and traffic load on the network links. To implement multicast, networks need to incorporate new rout- ing and forwarding mechanisms in addition to the existing unicast methods. Unfortunately, the necessary functions needed to realize multicast are not adequately supported in the cur- rent networks. The IP multicast solution has serious scaling and deployment limitations, and cannot be easily extended to provide more enhanced data services. Furthermore, and perhaps most importantly, IP multicast has ignored the economic nature of the problem, lacking incentives for service providers to deploy the service in wide area networks. Overlay multicast holds promise for the realization of large scale Internet multicast services. An overlay network is a virtual topology constructed on top of the Internet infras- tructure. The concept of overlay networks enables multicast to be deployed as a service network rather than a network primitive mechanism, allowing deployment over heteroge- neous networks without the need of universal network support. This dissertation addresses the network design aspects of overlay networks to provide scalable multicast services in the Internet. The resources and the network cost in the context of overlay networks are dif- ferent from that in conventional networks, presenting new challenges and new problems to solve. Our design goals are the maximization of network utility and improved service qual- ity. As the overall network design problem is extremely complex, we divide the problem into three components: the efficient management of session traffic (multicast routing), the provisioning of overlay network resources (bandwidth dimensioning) and overlay topol- ogy optimization (service placement). The combined solution provides a comprehensive procedure for planning and managing an overlay multicast network. We also consider a complementary form of overlay multicast called application- level multicast (ALMI). ALMI allows end systems to directly create an overlay multicast session among themselves. This gives applications the flexibility to communicate without relying on service providers. The tradeoff is that users do not have direct control on the topology and data paths taken by the session flows and will typically get lower quality of service due to the best effort nature of the Internet environment. ALMI is therefore suitable for sessions of small size or sessions where all members are well connected to the network. Furthermore, the ALMI framework allows us to experiment with application specific com- ponents such as data reliability, in order to identify a useful set of communication semantics for enhanced data services. To my grandmother Contents List of Tables : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : vii List of Figures : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : viii Acknowledgments : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : x 1 Introduction : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 1 1.1 Group Communications . 1 1.2 A Brief History of Internet Multicast . 4 1.3 Why Overlay? . 6 1.4 Contributions . 8 1.5 Outline . 10 2 Architecture of Overlay Multicast Networks : : : : : : : : : : : : : : : : : 11 2.1 Background on Internet Architecture . 11 2.2 Overview of Overlay Multicast Networks . 16 2.3 Benefits of Overlay Multicast Networks . 20 2.4 Cost of Overlay Multicast Networks . 22 2.4.1 Evaluation Methodology . 26 2.4.2 Comparisons with Network Multicast Trees . 28 2.5 Overview of Design Issues . 34 2.6 Related Work . 37 2.7 Summary . 39 3 Multicast