Virtual circuits Each wire carries many" virtual'circuits >)Forwarding based on virtual circuit (vc)identifier iP header: src, dst, etc Virtual circuit header: just Vc >)A path through the network is determined for each vc when the VC is established >Use statistical multiplexing for efficiency Can support wide range of quality of service ))No guarantees: best effort serv ice 》 Weak guarantees: delay<300msec,… Strong guarantees: e.g. equivalent of physical circuit 88 Virtual Circuits Each wire carries many “virtual” circuits. » Forwarding based on virtual circuit (VC) identifier – IP header: src, dst, etc. – Virtual circuit header: just “VC” » A path through the network is determined for each VC when the VC is established » Use statistical multiplexing for efficiency Can support wide range of quality of service. » No guarantees: best effort service » Weak guarantees: delay < 300 msec, … » Strong guarantees: e.g. equivalent of physical circuit