DVMRP

• Distance vector multicast routing protocol: Distance vector multicast routing protocol are abbreviated as DVMRP. These protocols are suitable for small networks which run on multicast traffic. First version of this protocol was created in year 1988 and was used in MBONE. It is dense multicast routing protocol and employs its own distance vector algorithm for computing routes in a network. This routing algorithm supports tunnels between the protocol's routers through unicast only networks.
Rouse (2007) states "The protocol sends multicast data in the form of unicast packets that are reassembled into multicast data at the destination."

The protocol is interior gateway protocol which is based on RIP that transmits connectionless multicast data to a group of receivers on network.

QuinStreetInc states "DVMRP tunnels multicast transmission within unicast packets that are reassembled into multicast data when they arrive at their destination."

Generic routing encapsulation or IP-in-IP encapsulation is used between these tunnels. Forwarding conflicts are automatically solved by route exchange process.

Advantage of DVMRP

1. It supports ASM and SSM
2. Exclusion of RPs make this protocol implementation simpler
3. It is effective for a network where receivers are distributed densely

Disadvantages of DVMRP

1. Store per source state is needed to be stored by all routers for every source in domain
2. This protocol is not scalable for the domains where most of the receivers are not willing to retrieve data; for example, the internet.