What are the uses of software ports ? 1. Connect client computer to server 2. Connect external devices to computer 3. Identify different services like email, file transfer 4. Connecting peripherals like cameras, scanners Select the answer using the code given below :
- A.1 and 2
- B.1 and 3
- C.2 and 3
- D.2 and 4
Correct answer
Explanation
The correct answer is B, 1 and 3. A software port is a logical number, not a physical socket, so it is used for network connections and for telling services apart. When a client computer contacts a server, it sends its request to the server's IP address together with a port number, and that number tells the server which program should answer. Each common service has its own well-known port: 80 for web pages (HTTP), 443 for secure web pages (HTTPS), 25 for sending e-mail (SMTP) and 21 for file transfer (FTP). Port numbers run from 0 to 65535. So statement 1 (connecting a client to a server) and statement 3 (identifying services like e-mail and file transfer) are correct. Options A and D are wrong because statements 2 and 4 describe hardware ports such as USB, HDMI and serial ports, into which cameras, scanners and other external devices are plugged. Option C is wrong because it includes statement 2, which again describes a hardware port. Exam tip: hardware port is a socket for devices; software port is a number for services.
Practice Questions
View allWhich among the following are the purposes of deploying a Firewall ? 1. Examine each packet arriving from Internet 2. Prevent unauthorised access 3. Block suspicious activity 4. Interconnect telephones Select the answer using the code given below :
- A.1 and 2 only
- B.1, 3 and 4
- C.2 and 3 only
- D.1, 2 and 3
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A firewall inspects incoming traffic, keeps out unauthorised users and blocks suspicious activity, but it has nothing to do with connecting telephones.
Read the full explanation →Which one of the following is not a logical operator?
- A.NOT
- B.OR
- C.AND
- D.Division
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Division is an arithmetic operator that works on numbers, while logical operators work on true and false values. Logical (Boolean) operators take one or more conditions that are either true (1) or false (0) and return a true or false result.
Read the full explanation →With reference to communication technologies, what is/are the difference/differences between LTE (Long-Term Evolution) and VoLTE (Voice over Long-Term Evolution)? 1. LTE is commonly marketed as 3G and VoLTE is commonly marketed as advanced 3G. 2. LTE is data-only technology and VoLTE is voice-only technology. Select the correct answer using the code given below.
- A.1 only
- B.2 only
- C.Both 1 and 2
- D.Neither 1 nor 2
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Neither statement describes the real difference between the two. LTE is a fourth-generation mobile broadband standard and is sold to customers as 4G, not 3G. VoLTE is not a separate network at all: it is a way of carrying voice calls as data packets over that same LTE network, using…
Read the full explanation →1 gigabyte in binary system is equivalent to
- A.1000 kilobytes
- B.1024 megabytes
- C.1200 megabytes
- D.10000 kilobytes
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In the binary system every step up the ladder of memory units is a factor of 2 raised to 10, that is 1024, so one gigabyte holds 1024 megabytes.
Read the full explanation →Consider the following:
1. Small memory
2. Less expensive memory
3. Fast memory
Which of the above are the characteristics of the cache memory?
- A.1 and 2 only
- B.2 and 3 only
- C.1 and 3 only
- D.1, 2 and 3
Show answer
Cache memory is small and very fast, but it is the most expensive memory per byte after the CPU registers, so statement 2 is wrong.
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