Answer: Packetizing, Routing, Forwarding, Flow Control, and Congestion control.
Step-by-step explanation:
Packetizing is where a routing device takes the information from the upper layer and creates the packets to send over to the correct format for layer 2 transmission.
Routing is telling the information where to travel on the network in the packet form, with the least expensive route for the traversal.
Forwarding is intrinsically linked to routing, meaning it basically has the same function to pass data to the correct destination on the network.
Flow Control is done here too where two routing devices will negotiate the transfer speed of the data.
Congestion Control is also done here where the router attempts to prevent huge overflow of datagrams being handled.
It is also possible for error control to be implemented here, but that is more likely to be implemented in layer 2 since data can be broken up into multiple packets in layer 3.
Cheers.