WDM multicasting in IP over WDM networks

Supporting WDM multicasting in an IP over WDM network poses interesting problems because some WDM switches may be incapable of switching an incoming signal to more than one output interface. An approach to WDM multicasting based on wavelength-routing, which constructs a multicast forest for each multicast session so that multicast-incapable WDM switches do not need to multicast, was proposed and evaluated previously. Such an approach requires global knowledge of the WDM layer. In this paper, we study WDM multicasting in an IP over WDM network under the framework of multiprotocol label switching (MPLS) using optical burst/label switching (OBS/OLS). We propose a protocol which modifies a multicast tree constructed by distance vector multicast routing protocol (DVMRP) into a multicast forest based on the local information only.