One advantage that circuit routing has over stateless routing is that of largely painless muxing / demuxing; and hence almost no buffer bloat. SONET can mux mul

One advantage that circuit routing has over stateless routing is that of largely painless muxing / demuxing; and hence almost no buffer bloat. SONET can mux multiple channels without the need for a single buffer. Obviously the downside is the lack of flexibility, interdependency and hence increased fragility.