Ann Oper Res (2008) 162: 159–169
Analysis and design of a playout buffer for VBR
B. Steyaert · K. Laevens · D. De Vleeschauwer ·
Published online: 5 February 2008
© Springer Science+Business Media, LLC 2008
Abstract A critical component in the delivery of VBR streaming video over packet-based
networks, is the playout buffer at the receiver side. As packets will incur a variable delay
within the network, a mechanism is needed to dejitter the stream and assure that packets are
played out at exactly the same rate at which they were generated by the sender.
Packet loss at the playout buffer can be induced by either underﬂow or overﬂow, and
we ﬁrst identify the general conditions under which these events occur. These general rules
require some knowledge on the network delay characteristics of an arbitrary packet, and are
then further developed and reﬁned, by taking a closer look at the case where a single delay
bottleneck exists within the network.
This analysis allows us to derive useful design rules, where we consider two cases, de-
pending on whether or not the receiver has knowledge about the delay the ﬁrst packet of the
stream has incurred. We conclude by demonstrating that the traditional playout paradigm
can be enhanced to guard against large initial delays.
Keywords Streaming media · Dejittering · Playout buffer · Underﬂow · Overﬂow
The delivery of pre-stored streaming media (such as video-on-demand (VoD)) or interactive
streaming media (such as video conferencing) over packet-switched networks has become
a predominant research area over the recent years. Given the large bandwidths of the trafﬁc
that are usually involved and the stringent QoS (Quality of Service) guarantees that these
applications require, a careful dimensioning of the available resources is mandatory.
B. Steyaert (
) · H. Bruneel
SMACS Research Group, TELIN, Ghent University, Sint-Pietersnieuwstraat 41, 9000 Gent, Belgium
K. Laevens · D. De Vleeschauwer
Alcatel-Lucent, Antwerp, Belgium