| 1: | Name two added features in ITU-T V.92 standard, compared to ITU-T V.90. |
| A1: | Modem on Hold and Quick Connect. |
| 2: | Name two limiting factors for the ability of the modem to connect. |
| A2: | The distance from the central office and the signal-to-noise ratio. |
| 3: | If the SNR is 40, how many times higher is the signal strength than noise strength? |
| A3: | 100. |
| 4: | How would you troubleshoot a case in which a pad of 3dB might be the root of the problem? |
| A4: | Make a long-distance call to the same number and see if the quality is better. |
| 5: | If AMI needs to transmit the octet 1 0 0 1 0 1 1 0, and the first mark is +, what are the next marks? Write the entire octet. |
| A5: | +00-0+-0. |
| 6: | If the preceding LSB in B8ZS is positive, what is the combination for 00000000? |
| A6: | 000+-0-+. |
| 7: | What is the main disadvantage of dial-back authentication? |
| A7: | This type of authentication requires a fixed phone number, which cannot be used by travelers. |
| 8: | Name the main phases of the PPP protocol. |
| A8: | Link Dead, Link Establishment phase, Authentication phase, Network-Layer Protocol phase, Link Termination phase. |
| 9: | What is the value 0xC223 in the protocol field of PPP? |
| A9: | 0xC223Challenge Handshake Authentication Protocol (CHAP). |
| 10: | Which protocol in the PPP suite establishes and configures the data-link connection? |
| A10: | Link Control Protocol ( LCP ). |
| 11: | What is the address field value of the PPP protocol? |
| A11: | 11111111. |
| 12: | Which packet types of LCP terminate the data-link connection? |
| A12: | 05, Terminate request; and 06, terminate acknowledgement . |
