1 - A protocol tester is to be used to investigate a link level fault where
would it be tee'd into the circuit ?
- between the modem and the equipment
- anywhere between the exchange modem and and the customers modem
- on the MDF
- on the IDF
2 - What is the main job of the link layer.
- error correction.
- end-to-end flow control
- speed changing
4 - What is transmitted to line when no information is
available for transmission.
- permanent 1s
- permenant 0s
5 - By monitoring an X.25 line how can you tell if the link is in the down
a) the network polls with SABMs
b) the network polls with DISCs
c) the customer polls with SABMs
d) the customer polls with DISCs
6 - If a computer calls another computer through Public Network and sends a frame with
a sequence number N(S) of 5, what sequence number will be received by the distant
end computer ?
a) N(S) = 4
b) N(S) = 5
c) N(S) = 6
d) not enough information here to tell
7 - What is the P bit used for ?
a) to indicate a sequence number error
b) to indicate PAD data is being transmitted
c) to demand an immediate response from the other end.
d) to indicate a FCS error
8 - what are the 9 types of frame ?
what is each one used for ?