Q. Example on audio transmission?
- QoS mechanism; switches (routers) first check resource requirements of a flow before admitting it to the network
Closed-loop congestion control
- back pressure
- Congested router inform preceding upstream router to reduce the outgoing traffic
- Choke point
- A packet sent by a router to the source (similar to ICMP source quench) to inform it of congestion
- implicit signaling
- The impediment in receiving an ACK can be a signal that a network is congested
- explicit signaling
- A router can explicitly send a special bit (flag) in the packet to the source or the destination