2. Compare the following:
• Flow Control vs. Congestion Control o Flow Control is used in Computer Networks because of its mechanism of controlling the data flow between sender and receiver. As a result if there is a slow receiver this is not overwhelmed with all the data transmitted by …show more content…
What is a 3 way hand shake? Is it better than 2 way hand shake?
In a Network, a 3 way handshake is a method used to create a connection between a local host or client and a server. Basically requires three steps from both the client and the server to exchange SYN and ACK packets before any communications begins. First the client sends a SYN packet asking the server if is open for a new connection, then the server responds with a confirmation packet or SYN/ACK, to what the client responds with an ACK packet and the connection is established.
3 way hand shake is better because the server gets the confirmation from the client that a SYN/ACK was received. With the 2 way handshake the server does not get any confirmation so the connection is closed.
6. When do we use Upward Multiplexing and Downward Multiplexing?
The Upward Multiplexing strategy is used by the transport layer to group transport connection base on their destinations. By mapping the groups to the minimum number of network connection, this application is very beneficial especially when the network connections get …show more content…
This strategy works by opening multiple network connections to distribute the traffics equally but we have to mention that this can be accomplished as long as the data links in the subnet are able to handle the capacity.
7. Suppose we design a reliable transport protocol that use only NAKs as feedback from receiver to sender:
• If the data rate is low (sender sends packets infrequently), is a NAK-only protocol better than an ACK-based protocol? Why? o In this case a NAK-only protocol will not be better because such protocol only detects lost of packet when a following packet is correctly received, consequently this can represent long error recovery time.
• if the data rate is high and the network drops only a small number of packets is a NAK-only protocol better than a ACK-based protocol? Why? o When the rate is high an ACK-based protocol is not appropriate because of the high overhead. If data rate is high NAK’s are sent occasionally oppose to ACKs never sent representing a significant reduction of feedback. So recovery under NAK could be faster.
8. What are the 3 transport layer services?