Routing
Routing schemes differ in how they deliver messages:
- Unicast delivers a message to a single specific node using a one-to-one association
- Broadcast delivers a message to all nodes in the network using a one-to-all association; a single datagram (or packet) from one sender is routed to all of the possibly multiple endpoints associated with the broadcast address. The network automatically replicates datagrams as needed to reach all the recipients within the scope of the broadcast, which is generally an entire network subnet.
- Multicast delivers a message to a group of nodes that have expressed interest in receiving the message using a one-to-many-of-many or many-to-many-of-many association
- Anycast delivers a message to any one out of a group of nodes, typically the one nearest to the source using a one-to-one-of-many[1] association where datagrams are routed to any single member of a group of potential receivers that are all identified by the same destination address. The routing algorithm selects the single receiver from the group based on which is the nearest according to some distance or cost measure.
Unicast is the dominant form of message delivery on the Internet. This article focuses on unicast routing algorithms.
Routing Algorithms
https://en.wikipedia.org/wiki/Routing#Delivery_schemes
Also see Messaging Pattern.