Every station reads every frame transmitted. The backoff procedure on collisions guarantees that no station will be starved. Ethernet and 802.3 differ by one field in the header. Every station that senses a collision, sends a jam signal. If an ack is not received within a specified time, a retransmission occurs.
Virtual circuits are a type of circuit switching.
Virtual circuit hop level flow control is handled by the link level protocol. The link layer manages buffer allocation and deallocation for the network layer. The bandwidth delay product is a measure of how much pipelining is needed for efficient operation of a window oriented transport protocol. Assume a 200 ms round-trip time and a network bandwidth of 500 megabits per second. Assume the network of Figure 1 with links labelled by costs.