It has long been known that one can speed the processing time of a packet by a node by adding information to the packet header. Until recently, however, bandwidth was more expensive than the processing power of the node. As the bandwidth of links increases, node processing is becoming the more limited resource. As a result, it seems logical to add bits to the packet to speed up node processing.
Source hashing is similar to hashing in a database.
A somewhat randomized pointer is created by the source and translated toward the destination by the interceding nodes. It does not require a path setup, so it is connectionless in nature. The idea of DML is to allow extensions of the data processing that can be done at each layer, such as encryption. The problem with any packet routing network is knowledge of paths. It is always likely that the source will know the destination.