A Scheme for Real-Time Channel Establishment
                   in Wide-Area Networks


Domenico Ferrari, FELLOW, IEEE, and Dinesh C. Verma


                          Abstract


     Multimedia communication involving digital audio and/or
digital  video has rather strict delay requirements. A real-
time channel is defined in this paper as a  simplex  connec-
tion  between  a  source  and a destination characterized by
parameters representing the performance requirements of  the
client. A real-time service is capable of creating real-time
channels on demand and guaranteeing their performance. These
guarantees  often  take  the  form  of  lower  bounds on the
bandwidth allocated to a channel and  upper  bounds  on  the
delays to be experienced by a packet on the channel.

     In this paper, we study the  feasibility  of  providing
real-time  services  on  a packet-switched store-and-forward
wide-area network  with  general  topology.  We  describe  a
scheme  for the establishment of channels with deterministic
or statistical delay bounds, and present the results of  the
simulation  experiments  we  ran to evaluate it. The results
are encouraging: our approach satisfies the guarantees  even
in  worst-case situations, uses the network's resources to a
fair extent, and efficiently handles channels with a variety
of  offered  load  and burstiness characteristics. Also, the
packet transmission overhead is quite low, and  the  channel
establishment  overhead  is small enough to be acceptable in
most practical cases.