Which Frame Relay feature is responsible for transmitting keepalives to ensure that the PVC does not shut down because of inactivity?（）

A. Provide common view of entire topology
B. Exchange routing tables with neighbors.
C. Calculates shortest path.
D. Utilizes event triggered updates.
E. Utilizes frequent periodic updates.

A. Use of full duplex mode.
B. Creation of new collision domain.
C. Creation of new broadcast domain.
D. Addition of hub to the network.
E. Use of switches in the network.
F. Amount of ARP or IPX SAP traffic.

A. Transport layer divides a data stream into segments & adds reliability & flow control information
B. Data link layer adds physical source & destination address & an FCS to the segment
C. Packets are created when the network layer encapsulate a frame with source & destination host address& protocol related control information
D. Packets are created when the network layers adds layers 3 address & control information to a segment
E. The presentation layer translated bits into bits into voltages for transmission across the physical link