It has only two major phases, which are Route Discovery and Route Maintenance.
Route Reply would only be generated if the message has reached the intended destination node (route record which is initially contained in Route Request would be inserted into the Route Reply).
Dynamic Source Routing (DSR) is a routing protocol for wireless mesh networks.
It is similar to AODV in that it forms a route on-demand when a transmitting node requests one.
However, it uses source routing instead of relying on the routing table at each intermediate device.
Determining source routes requires accumulating the address of each device between the source and destination during route discovery.
Otherwise, the node will reverse the route based on the route record in the Route Request message header (this requires that all links are symmetric).
In the event of fatal transmission, the Route Maintenance Phase is initiated whereby the Route Error packets are generated at a node.