Delay Jitter Control for Real-Time Communication
               in a Packet Switching Network

                      Dinesh C. Verma
                         Hui Zhang
                      Domenico Ferrari

                 Computer Science Division
 Department of Electrical Engineering and Computer Sciences
            University of California at Berkeley
         & International Computer Science Institute
                    Berkeley, California


                          ABSTRACT

     A real-time channel is a simplex connection between two
nodes  characterized  by parameters representing the perfor-
mance requirements  of  the  client.  These  parameters  may
include a bound on the minimum connection bandwidth, a bound
on the maximum packet delay, and  a  bound  on  the  maximum
packet  loss rate. Such a connection may be established in a
packet-switching  environment  by  means  of   the   schemes
described  by  some  of  the authors in previous papers.  In
this paper, we study the feasibility of bounding  the  delay
jitter  for  real-time  channels in a packet-switched store-
and-forward wide-area network with general topology, extend-
ing  the  scheme  proposed in the previous papers.  We prove
the correctness of our solution, and study its effectiveness
by means of simulations. The results show that the scheme is
capable  of  providing  a  significant  reduction  in  delay
jitter,  that  there  is no accumulation of jitter along the
path of a channel,  and  that  jitter  control  reduces  the
buffer space required in the network significantly.