1.In ATM the HEC field:

　　A:Provides error check for the whole ATM cell

　　B:Provides error check for the ATM cell header only

　　C:Provides error check for the user data only

　　D:Could be used for cell delineation

　　E:Can be used to correct 2 errors

　　F:Is not used at all; HEC was never implemented.

　　Correct Answers:　B, D

　　2.Click the Exhibit button to view the topology. Host 1 and Host 2 are on Ethernet LANs in different buildings. A serial line is installed between two Cisco routers using Cisco HDLC serial line encapsulation. Routers A and B are configured to route IP traffic. Host 1 sends a packet to Host 2. A line hit on the serial line causes an error in the packet. When this is detected, the retransmission is sent by:

　　A: Host 1

　　B: Host 2

　　C: Router A

　　D: Router B

　　E: Protocol analyzer

　　Correct Answers:　A

　　3.What is true about Cisco IGX VC queues for Frame Relay?

　　A: There is a queue for every Frame Relay connection going from the CPE to the Cisco IGX switch.

　　B: They do not apply to ForeSight connections.

　　C: There is a queue for every Frame Relay port going from the Cisco IGX switch to the CPE.

　　D: It is recommended that these queues be no larger than 100 bytes.