Video presentation: Network Layer: Introduction. Networklayer services. Routing versus forwarding. The networklayer data plane and control plane. Service models, besteffort service.

Computer networks class.
Jim Kurose
Textbook reading: Section 4.2.1, 4.2.2 and 4.2.3, Computer Networking: a TopDown Approach (8th edition), J.F. Kurose, K.W. Ross, Pearson, 2020.
See http://gaia.cs.umass.edu/kurose_ross for more open student resources.