Mixed practice set 3

The last mixed set before the drill and the final test.

1. NAT · 1 mark

   One packet, 5 links store-and-forward, T_t = 2 ms and T_p = 1 ms per link. Arrival time (ms)?

   Write your answer before opening the key.

2. NAT · 1 mark

   Bits that can be sent in one RTT of 50 ms on a 1 Gbps link, in millions (B × RTT)?

   Write your answer before opening the key.

3. MSQ · 1 mark

   A router has two interfaces; one leads to a switch with 5 hosts. Which are true?

   1. The switch side has 5 host collision domains plus its router link.
   2. All hosts on the switch are one broadcast domain.
   3. The switch blocks broadcasts.
   4. The router splits broadcast domains.
4. NAT · 1 mark

   Ethernet frame size (bytes) carrying 100 data bytes?

   Write your answer before opening the key.

5. NAT · 1 mark

   Usable host addresses in one classful Class B network?

   Write your answer before opening the key.

6. MCQ · 2 marks

   Aggregate 200.1.1.0/26, 200.1.1.64/26, 200.1.1.128/26, 200.1.1.192/26:

   1. 200.1.1.0/24
   2. 200.1.1.0/25
   3. 200.1.0.0/23
   4. 200.1.1.0/26
7. NAT · 1 mark

   IPv4 header with HLEN = 6 and total length 1024. Data bytes?

   Write your answer before opening the key.

8. NAT · 2 marks

   NAPT using source ports 1024–65535 on one public IP: maximum simultaneous mappings?

   Write your answer before opening the key.

9. NAT · 1 mark

   TCP sequence wrap-around time at 10 Gbps, in seconds (3 decimals)?

   Write your answer before opening the key.

10. NAT · 2 marks

    SRTT = 50 ms, RTTVAR = 5 ms, new sample 70 ms, α = 1/8, β = 1/4 (RFC 6298 order). New RTO (ms)?

    Write your answer before opening the key.

11. MCQ · 1 mark

    HTTP 304 means:

    1. OK
    2. Not Modified
    3. Not Found
    4. Moved Permanently
12. NAT · 2 marks

    Both stations at their 3rd collision. P(station A wins) (4 decimals)?

    Write your answer before opening the key.