A Protocol For Relative Quality-of-Service In TCP/IP-Based Internetworks

Abstract

A new protocol is presented that controls the qualityof-service of simplex end-to-end packet streams in a TCP/IP based internetwork. The protocol, called TReg for Transport Regulation, limits the use of network resources by a rate control mechanism implemented at the tra c sources. The set of ows is partitioned into di erent tra c classes based on the application type, e.g., video tra c, audio tra c, or bulk data. The rate control mechanisms at the trafc sources adapt to the current tra c load such t h a t ows within the same tra c class obtain the same quality-of-service (Relative Quality-of-Service). M e asurements of a prototype implementation in a netwo r k o f w orkstations demonstrate the e ectiveness of the TReg protocol.

Kommunikation

“…Das Konzept von ROBIN weist einige Parallelen zu den Gedanken des in Kapitel 2.1. vorgestellten Verfahrens TReg [LT95] insbesondere in Bezug auf die Philosophie der relativen Dienstgüte auf. Die Realisierung der Bandbreitenregelung von TReg innerhalb der Anwendungen, also oberhalb der Transportprotokolle, stellt jedoch einen entscheidenden Nachteil dar: Alle Anwendungsprogramme müssen um die TReg-Komponenten ergänzt werden, sonst können unkooperative Anwendungspro-…”

Motivation of an end-to-end regulation of bandwidth in intra-networks: The ROBIN concept

“…Liebeherr, 1995) enhances applications on top of the TCP/UDP protocols to control the application data flows. With the TReg concept of Liebeherr (1995), all application processes using the service of TCP or UDP have to be enhanced by adding TReg components (so-called ''TReg-Stub" and ''TReg-Daemon"). These components have a global view on all active TReg flows in the network.…”

“…Therefore, ROBIN is able to include congestion unresponsive flows (like UDP or other transport protocols) in it<; bandwidth distribution. The available bandwidth of the network (in particular part<; of it being a bottleneck) is shared according to the principle of relative QoS a<; used in (Liebeherr, 1995): Different applications are classified according to their requirement<; in terms of minimum bandwidth (e.g. for video) or relative priorities (e.g.…”