We consider a variable bit-rate connection with a deterministically shaped
random traffic process, as specified by communications networking standards
. Regarding randomness, we assume no restricted model other than the natura
l requirement that the process be stationary and ergodic, Given only the sh
ape parameters, we consider the open problem of determining the maximum ser
vice bandwidth required to achieve a given bound on the probability that th
e packet-transfer delay exceeds a certain threshold. The shape parameters t
ogether with a probabilistic bound on packet-transfer delay define a variab
le bit-rate "channel;" an equivalent problem is to determine the "capacity"
of this channel. To this end, we consider a queue with a constant service
rate and a shaped arrival process and obtain tight bounds on queue occupanc
y and queueing delay. In particular, we describe that traffic pattern (amon
g all stationary-ergodic and deterministically constrained arrival processe
s) which achieves the probabilistic bound.