BUFFER SPACE ALLOCATION FOR REAL-TIME CHANNELS
               IN A PACKET-SWITCHING NETWORK


            Domenico Ferrari and Dinesh C. Verma
                 Computer Science Division
 Department of Electrical Engineering and Computer Sciences
                  University of California
        and International Computer Science Institute
                Berkeley, California, U.S.A.





                          Abstract

     Broadband integrated networks will have to offer  real-
time  communication  services;  that  is,  they will have to
transport information with performance guarantees.  A  paper
previously  published  by the authors presented a scheme for
establishing real-time channels in a  pure  packet-switching
network; that scheme did not include any method for allocat-
ing buffer space in the  network's  nodes  to  the  channels
being  established. This paper completes the description and
evaluation of  that  scheme,  since  it  presents  one  such
method, and some of the results of the extensive simulations
performed to test it. The method is found to be correct  and
to  have a low overhead. While the utilization of the buffer
space allocated to the statistical channels is  often  quite
low,  thereby  indicating that our worst-case approach tends
to overallocate space  to  those  channels,  the  space  our
method  gives  to deterministic channels seems to be reason-
ably well utilized.