Towards Multi-class Based Multicast Routing

Maria João Nicolau*, António Costa, Alexandre Santos and Vasco Freitas

Universidade do Minho
Departamento de Sistemas de Informação*
Departamento de Informática
P-4710-057 Braga, Portugal

Tel.: +351 253 604430
Fax.: +351 253 604471
E-mail: joao (at), {costa,alex,vf} (at)


While Differentiated Services reach maturity, and a few per hop aggregate behaviors are being standardized, little efforts are being carried out to enforce class differentiation by selecting alternative routes. Within a differentiated services multicast scenario, multiple multicast forwarding trees must be found, one per Class of Service (CoS), in order to comply with different per-class Quality of Service (QoS) requirements. This paper presents a new multicast routing protocol enabling per class multicast tree computation. The proposed heuristics enable directed trees establishment, instead of reverse path ones, due to the importance of link asymmetry within an environment which is, essentially, unidirectional. The main assumption supporting this work is that a per class path computation may well complement, at routing level, node level differentiation techniques, thus providing per class differentiated handling. The strategy presented is also useful for network traffic engineering as it potentially enables traffic distribution along different network links.

6th IEEE International Conference on High Speed Networks and Multimedia Communications, HSNMC'03, Estoril, Portugal, Jul 23-25, 2003.     LNCS, vol 2720, pp. 52-51, Springer-Verlag, 2003