Tips for NS3 simulator

 Some tips:

1. You need to be good at C++. Have to understand the basic concepts such as smart pointer, class, object, struct. Have to know how to create classes so that later we can design your own custom class and extend or add some new features in the class.
2. In our life, sometimes it is better to know our own limitations so that we can work on it. Similarly, we also have to understand the limitations of NS-3 code.

What is the difference between persistent and non-persistent HTTP

 In non-persistent HTTP, a brand new TCP connection must be established and maintained for each requested object. When a user requests a Web page (for example clicks on a hyperlink). Suppose the web page consists of a base HTML file and 10 JPEG images. So in case of non-persistent HTTP, 11 TCP connections are generated.

In case of persistent HTTP, the server leaves the TCP connection open after sending a response. Subsequent requests and responses between the same client and server can be sent over the same connection. So, the entire web page (11 objects) can be sent over a single persistent connection.

What are some computer science job interview questions?

 Question 1: Difference between network security and cyber security?

Question 2: What is degree of multiprogramming?

Question 3: Difference bandwidth and throughput?

Question 4: What is context switching?

Question 5: What is multihoming? 

Answer: Multihoming is the practice of connecting a host or a computer network to more than one network structure in order to increase reliability or performance.

Question 6: What is inside a router?

Question 7: Difference between #include<> and #include” ” in C/C++ with Examples.

Question 8: In which header file, we can find the definition of malloc function?

Answer:  stdlib.h

What is the difference between CAM and TCAM in networking?

 

TCAM is a special version of CAM. The main characteristic of both CAM and TCAM is that it is able to search all its entries in parallel. So the content search takes only one clock cycle. Though speed is high, it is expensive.

Main difference between CAM and TCAM

i) CAM requires an exact match on the key stored in its table whereas TCAM allows partial match.

In TCAM data are stored and queried using 0, 1 and X unlike 0 and 1 in case of CAM. X can be referred don’t care or wild card state. The name Ternary comes from the use of three states.

ii) From usage point of view in networking devices:

CAM is used in Ethernet switch (MAC table look up )whereas in TCAM is used in router (router prefix look up).