MOSPF is multicast extension to OSPF. This protocol is extension of OSPF which is a unicast routing protocol which make MOSPF a combination of unicast and multicast protocol. MOSPF was documented in RFC1584 in the year 1994, since then no other version of the protocol has been deployed.
Rouse (2008) states "MOSPF (Multicast Open Shortest Path First) is an extension to the OSPF (Open Shortest Path First) protocol that facilitates interoperation between unicast and multicast routers."
MOSPF do not exchange any messages with neighbours for developing any multicast distribution trees. The routers employed in the network flood the information of location of all the receivers and distribution trees are calculated by MOSPF by its own. Due to this, all routers have same information so same trees will be calculated and there is no need of any designated forward mechanism or designated, assert router are required.
Advantages for MOSPFRP are not necessary to be defined
Disadvantages of MOSPF• Scalability is limited• The protocol does not support SSM