Scalable multicast MPLS protocol for next generation broadband service convergence network

Abstract

With explosive dissemination of broadband IP access services, like xDSL and FTTH, many service providers seek a chance for deploying new IP based broadband services networks for their customers. Among multiple candidates, content distribution (CD), interactive multi-media (IMM) and virtual private network (VPN) services are the most attractive broadband services for service provider and their customers. The quality of service (QoS) control and traffic engineering (TE) mechanism with strict reliability are essential functions to differentiate these services from conventional best effort IP access service and to make this broadband services network as a new communication infrastructure. Because MPLS already has all of these mechanisms in its protocol architecture, it is assumed that developing broadband IP service network by MPLS technology is the most promising way. But many of these services, such as video broadcasting, video conference and VPN multicast service require not only point-to-point (P2P) transmission capability but also point-to-multipoint (P2MP) transmission capability with much stricter QoS control, more sophisticated TE and more stable reliability control requirement. Therefore, P2MP capability extension is required to conventional MPLS. This paper proposes a scalable multicast MPLS protocol that can establish P2P and P2MP LSP simultaneously. The P2MP extension is realized on RSVP-TE (RFC3209). By introducing tree explicit route object (TERO) and enhancing conventional Path/Resv signaling procedures to enable tree based LSP setup, the proposed protocol can set any kind of P2MP LSPs; cost minimum (Steiner) P2MP LSP, delay-constrained P2MP LSP according to application demands. The proposed protocol also supports dynamic partial tree modification mechanism; Grafting and Pruning to handle dynamic multicast traffic. Therefore, P2MP LSP is modified easily. Several scalability and performance evaluations are conducted in this paper to prove its feasibility. This paper also proposes a multicast constrained shortest path fast (CSPF) mechanism to support dynamic QoS constrained P2MP LSPs setup. We confirmed that proposed schemes are scalable and has enough performance to be applied to future large scale IP service convergence network.