Layer 3
3: Network layer (e.g. IP)
- Unreliable (best effort)
- if packet gets lost, network layer doesn’t care for higher layers can resend lost packets
- Forwards packets hop by hop
- encapsulates network layer packet inside data link layer frame
- different framing on different underlying network types
- receive from one link, forward to another link
- There can be many hops from source to destination