Computer Networks a systems approach Question 1 Briefly desc

(Computer Networks: a systems approach)                     

Question: 1) Briefly describe best effort service.

2) Give a short description of a three-way handshake in TCP.

3) Write an overview of a sliding window.

4) What is wrap around and how can it be avoided?

5) Explain the two major components of a RPC.

Solution

1) Best effort service is employed for error control and utilized for retransmission of frames which is surplus due to corrupt. Best effort service needs reliability to be provided by higher layer protocol. Link Layer and Network Layer are some Best effort services.

2) The usual process of set up a connection between a TCP client and server engages three steps

3) Sliding window is used for reliable delivery of packets. It is two way communication and used two type frame

The basic thought of sliding window protocol is that both sender and receiver remains a Window of admission. The sender keeps the value of excepted acknowledgment. While the receiver keeps the value of excepted receiving frame. When it receives an acknowledgment from the receiver the sender advances the window. When it receive expected frame, the receiver advances the Window.

4) Wraparound is the process in which check the duplicate packets and rejection of packets from wrap sequence window. To avoid this use PAWS is one method the network bandwidth goes up.

5) Two Major components: Calling procedure is located in the local machine and contacts the remote procedure to be executed by placing a request message to the call procedure.

Calling procedure may be located in the same computer as the calling procedure or on a different computer. Gets the parameter from the request message sent by calling procedure and executes accordingly giving the results via a reply message to the calling process.