- Fault tolerance based on replicated services: Client request multicast to a bunch of server.
- Finding the discovery servers in spontaneous networking
- Better performance through replicated data: when a value changes it is multicasted
- Propagation of event notifications:
- Sender is unaware of the identities of the recipients
- Multicast group is a class D Internet address, first 4 bits are 1110
- Membership is dynamic
- Only available via UDP
- When a packet arrives copies are delivered to each socket bound to the group
- Multicast address permanent (126.96.36.199 to 188.8.131.52) or temporary.
- Failure Model: Same as UDP
Reliability and Ordering:
- Fault tolerance based on replicated services: Bad, it can create inconsistent servers’ state
- Finding the discovery servers in spontaneous networking: Ok, some drops doesn’t affect this one.
- Better performance through replicated data: same as above
- Propagation of event notifications: same