Question one: choose the correct answer

1. Which is NOT supported by TCP? (A) error control (B) flow control (C) congestion control (D) delay control.
2. Which is NOT supported by UDP? (A) connectionless (B) best effort (C) multiple processes (D) in-order.
3. When a DNS server receives two queries from the same host, which field of the query message is different? (A) source IP address (B) source UDP port number (C) destination IP address (D) destination UDP port number
4. A browser establishes two parallel TCP connections to the same Web server. When the host running the browser receives a segment from the server, which field of the segment is different? (A) source IP address (B) source TCP port number (C) destination IP address (D) destination TCP port number.
5. The technique that a sender sends one packet then waits for its receivers response is called (A) store-and-forward (B) stop-and-wait (C) pipelining (D) retransmission
6. An acknowledgment for a packet with sequence number n indicating that all packets with a sequence number up to and including n have been correctly received at the receiver is called (A) negative acknowledgement (B) selective acknowledgement (C) positive acknowledgement (D) duplicate acknowledgement
7. IP is a protocol of the (A) link layer (B) network layer (C) transport layer (D) application layer.
8. Which delay is the time waiting at the output link for transmission and depends on the congestion level? (A) nodal processing (B) transmission (C) propagation (D) queuing
9. Which are unguided media? (A) twisted-pair copper wire (B) coaxial cable (C) power-line wire (D) radio channels
10. Each Web object is addressable by a (A) HTTP (B) HTML (C) URL (D) XML
11. Which does not strictly belong to the hierarchy of DNS servers? (A) root name server (B) top-level server (C) authoritative DNS server (D) local name server
12. Which must have a buffer to receive out-of-order data? (A) Go-Back-N (B) Selective Repeat (C) TCP (D) stop-and-wait
13. Which must have a buffer to receive out-of-order data? (A) Go-Back-N (B) Selective Repeat (C) TCP (D) stop-and-wait
14. What is the type of the answer to a DNS query for the IP address of the authoritative name server for the domain? (A) Type A (B) Type NS (C) Type CNAME (D) Type MX