Question

Date Q.1- Deternine if the following statements are f ue ow Fae I- Different URLs can be mappel to the same IP wlivess 2- HTML refers the application layer rotoeol that is used to tranafer wehpages to m server to the client 3- The web browser can serve as an HTTP elient or an TTP serve 4- When the congestion point is reached, the eongestion control algorithn wehuces the congestion window into half of its previous value s- The domain name service (DNS) umally uses the UDIP protoee o. Ira TCP sender sends a segment with the FIN flag set, the TCP weivew on repy with s segment contains only the ACK fag set 7- Domain 8. The UDP protocol is used by real time applications eh as 9. In the slow start phase of the TCP congestion control algorithm, the wender daubles the uree where all the nodes in the tree have lahe voice and vide ain names are organined in a congestion window size each time it reveives an ACK 10- You can only use a domain name if the name in registered

Answer 1

1. True

• You can have multiple HTTP site configured with different combination of above. The binding, for example 192.168.1.0:80 can be configured to site “MyServer1.com”. That means if I browse to IP-address 192.168.1.0 over port 80 then I will hit the site “MyServer1.com”. I can have the binding as 192.168.1.0:80:myserver2.com configured for site “MyServer2.com”. That means when I browse the site over IP-address 192.168.1.0 over port 80 with a host header as “myserver2.com” then I will hit the site MyServer2.com. This allows multiple DNS hostnames on a single server at the same IP address.

2. False

3. True

4. True

• Whenever there is a timeout, the threshold is set to one half of the current congestion window and the congestion window is then set to one.

5. True

• DNS uses the User Datagram Protocol (UDP) on port 53 to serve DNS queries. UDP is preferred because it is fast and has low overhead.

6. True

• The connection termination phase uses a four-way handshake, with each side of the connection terminating independently. When an endpoint wishes to stop its half of the connection, it transmits a FIN packet, which the other end acknowledges with an ACK. Therefore, a typical tear-down requires a pair of FIN and ACK segments from each TCP endpoint. After the side that sent the first FIN has responded with the final ACK, it waits for a timeout before finally closing the connection.

7. True

8. True

• UDP is the Datagram oriented protocol. This is because there is no overhead for opening a connection, maintaining a connection, and terminating a connection. UDP is efficient for broadcast and multicast type of network transmission.

9. True

• A sender begins transmissions to a receiver by slowly probing the network with a packet that contains its initial congestion window (cwnd).
• The client receives the packet and replies with its maximum buffer size, also known as the receiver’s advertised window (rwnd).
• If the sender receives an acknowledgement (ACK) from the client, it then doubles the amount of packets to send to the client.
• Step 3 is repeated until the sender no longer receives ACK from the receiver which means either congestion is detected, or the client’s window limit has been reached.

10. False