DiffServ uses nodal PHB and network engineering to achieve “domain PHB”. Common PHB are (BE) Best Effort, (AF) Assured Forwarding, and (EF) Expedited Forwarding. IntServ operates only (E2E) end-to-end. Commonly uses RSVP for signaling. Not a scalable model, inefficient resource usage. SWAN is stateless model. Classifies traffic to RT, real-time, and BE. Traffic is demoted to BE when bandwidth becomes limited. INSIGNIA, state oriented model. Requires reservation, but automatically recovers from mobility scenarios.