Mixed practice set 1

Twelve questions from every phase, in random order. Do them without notes, then check and reveal.

1. NAT · 1 mark

   Transmission delay (ms) of a 1250-byte packet on a 25 Mbps link?

   Write your answer before opening the key.

2. MCQ · 1 mark

   Which device works up to the data link layer?

   1. Hub
   2. Switch
   3. Router
   4. Repeater
3. NAT · 1 mark

   Maximum throughput of pure ALOHA, in percent (1 decimal)?

   Write your answer before opening the key.

4. NAT · 1 mark

   Usable hosts in a /29 subnet?

   Write your answer before opening the key.

5. MCQ · 2 marks

   Network address of 10.1.77.200/19?

   1. 10.1.64.0
   2. 10.1.72.0
   3. 10.1.77.0
   4. 10.1.0.0
6. NAT · 2 marks

   A 2400-byte datagram (20-byte header) meets an MTU of 1000. How many fragments?

   Write your answer before opening the key.

7. NAT · 1 mark

   Stop-and-wait efficiency when a = 2 (3 decimals)?

   Write your answer before opening the key.

8. NAT · 1 mark

   Maximum Go-Back-N sender window with 4-bit sequence numbers?

   Write your answer before opening the key.

9. NAT · 1 mark

   A client's SYN carries ISN 5000. Sequence number of its first data byte after the handshake?

   Write your answer before opening the key.

10. MCQ · 1 mark

    Which DNS record names a domain's mail server?

    1. A
    2. MX
    3. CNAME
    4. NS
11. NAT · 1 mark

    Internet checksum (decimal) of the 16-bit words 0x1111 and 0x2222?

    Write your answer before opening the key.

12. NAT · 1 mark

    Persistent HTTP without pipelining: base + 3 small objects, RTT 10 ms. Total ms?

    Write your answer before opening the key.