Interactive voice and video applications (e.g. teleconferencing) over
multi-hop packet-switched networks require bounds on delay, loss and j
itter. This paper compares routing algorithms and admission control me
thods which are intended to provide the quality of service required by
such applications. The method of comparison is detailed simulation. A
s part of this work, we propose several novel real-time routing algori
thms. The best-performing routing algorithm is a new method which take
s into account the constraints imposed by the admission control algori
thm. A routing algorithm similar to those used in the phone system is
the worst of the dynamic algorithms; static routing is far worse than
any of these. The differences between the routing algorithms are great
est when the network is highly connected, and when admission control c
onstraints are difficult to meet. The issue of fairness is also consid
ered in the evaluation of the routing algorithms. Three admission cont
rol algorithms were compared under varying traffic conditions and QoS
requirements. The impact of traffic shaping on link utilizations was i
nvestigated. Overall, the choice of admission control method was more
important than the choice of routing algorithm. This work is the first
detailed evaluation of routing algorithms for voice and video traffic
in multi-hop networks that provide strong end-to-end guarantees.