Also, simulation of a set of wireless ad hoc multicast protocols such as On-Demand Multicast Routing Protocol (ODMRP), Multicast Ad-hoc On-Demand Distance Vector (MAODV), Multicast Open Shortest Path First (MOSPF), and PIM is evaluated under various network scenarios using QUALNET .
Therefore this makes PIM "unicast routing protocol independent," compared to other multicast routing protocols derived from either link-state (MOSPF) or distance-vector (DVMRP) routing .
MOSPF uses IGMP to discover the location of group members.
The sample IP internet pictured in Figure 1 will be used to illustrate MOSPF's properties.
As MOSPF forwards an IP multicast datagram from its source to the various group members, the routers and network segments that the datagram transits form a graph without loops or a tree.
However, while MOSPF optimizes the path to any given group member, it does not necessarily optimize the use of the internetwork as a whole.
The path of a multicast datagram in MOSPF can vary based on its TOS classification.
In an additional optimization, MOSPF provides explicit support for IP multicast's expanding ring search procedure.
MOSPF routers can be mixed with non-multicast OSPF routers.
All network segment types that are supported by the base OSPF protocol are also supported by MOSPF: broadcast networks (e.g., ethernet), point-to-point networks (e.g., synchronous serial lines) and non-broadcast multi-access (NBMA) networks (e.g., an X.25 PDN or a Frame relay network).
MOSPF provides algorithms for forwarding multicast datagrams between OSPF areas,(3) and an algorithm for importing multicast datagrams from another Autonomous System.
In order to calculate optimal paths for multicast datagrams, MOSPF augments the OSPF link state database with new information, and defines an additional calculation to be performed on the database.