Virtual Circuits or Datagrams
external virtual circuit, internal virtual circuit
- user requests a VC setup, net sends packets along a specific path (TYMNET, SNA)
external virtual circuit, internal datagrams
- network handles each packet independently, may follow different paths but network delivers packets in order (Internet)
external datagrams, internal virtual circuit
external datagrams, internal datagrams
- each packet handled independently (Internet)