A traffic flow carries data that is exchanged between the terminals during a communication service. In addition to unidirectional flows from a sender to a receiver, multicast or broadcast flows distribute data from a source to many destinations via splitting points in switching nodes of the network. Traffic flows on the Internet are transferred as a sequence of IP packets with protocol headers being added to the payload data to facilitate routing and delivery through the network. Internet standardization refers to an IP flow as a collection of successive packets with the same IP addresses and transport layer ports for source and destination as well as the same type of service marked in the packet headers. The TCP protocol initiates and terminates a flow by setting up and closing a connection in a handshake with the receiver, whereas UDP spontaneously starts and stops to send packets and flows.
Published in Chapter:
Network Planning and Dimensioning for Broadband Access to the Internet Regarding Quality of Service Demands
Franz Hartleb (T-Systems, Germany), Gerhard Haßlinger (T-Systems, Germany), and Sebastian Kempken (University of Duisburg-Essen, Germany)
Copyright: © 2009
|Pages: 15
DOI: 10.4018/978-1-60566-194-0.ch054
Abstract
An ongoing challenge in telecommunication is the integration of a variety of services on broadband access platforms at increasing transmission speed. Traditional Internet services like file transfer, email and web browsing, are carried on the same multi service IP platforms with voice, video and television over IP, online gaming, peer-to-peer and grid networking etc. While broadband access is established as a standard equipment for homes, the networking capacities in the access and the backbone are steadily extended to keep pace with higher traffic volumes. Together with the spectrum of services, the traffic mix on the aggregation levels becomes increasingly versatile with different demands for end-to-end transport in terms of throughput, loss and delay sensitivity. The chapter focuses on planning and traffic engineering for link bandwidth and buffers as main resources in communication platforms based on measurement and statistical properties of traffic growth and variability. We summarize quality of service demands of main Internet applications and mechanisms to control and stabilize the performance of ISP network platforms on different time scales. Load thresholds for link dimensioning are derived with regard to quality of service (QoS) demands and the variability in source and aggregated profiles. Finally, link level and network wide traffic engineering is addressed together with load balancing techniques.