Fundamentals of Network Communication complete course is currently being offered by University of Colorado through Coursera platform and is being taught by Xiaobo Zhou.
About this Course
In this course, we trace the evolution of networks and identify the key concepts and functions that form the basis for layered architecture.
We introduce examples of protocols and services that are familiar to the students, and we explain how these services are supported by networks.
Further, we explain fundamental concepts in digital communication, and focus on error control techniques that include parity check, polynomial code, and Internet checksum.
Students will be required to have some previous programming experience in C-programming (C++/Java), some fundamental knowledge of computer organisation and IT architecture and a background in computer science is a plus.
Also Check: How to Apply for Coursera Financial Aid
Week 1 Graded Assessment - Communication Networks and Services
1. Which of following protocol is HTTP built upon?
- IP
- SMTP
- TCP
- UDP
2. Which of following requirements are necessary for packet networks to support multiple and diverse applications?
- Transfer arbitrary message size
- Low delay for interactive applications
- Packets have maximum length
- All of the above
3. What was the concern of the telephone system that motivated the ARPANET design?
- Scalability
- Vulnerability
- Efficiency
- None of the above
4. Which of the following is an application layer protocol?
- TCP
- UDP
- DNS
- HTTP
5. Which of the following are features of ARPANET design?
- Connectionless packet transmission
- Routing tables at the packet switches
- Destinations identified by unique addresses
- All of the above
6. Bluetooth is an example of
- Wide Area Network
- Local Area Network
- Metropolitan Area Network
- Personal Area Network
7. In the layer hierarchy as the data packet moves from the upper to the lower layers, headers are
- Modified
- Removed
- Rearranged
- Added
8. The ________ is the physical path over which a message travels
- Medium
- Path
- Route
- Protocol
9. Three or more devices share a link in ________ connection
- Unipoint
- Multipoint
- Point to Point
- None of the above
10. Which of the following is true for Transport Control Protocol
- Connection oriented
- Process to Process
- Transport layer protocol
- Connectionless
Week 2 Graded Assessment - Layered Architecture
- IP address
- Physical address
- Domain name
- None of the above
2. Suppose an application layer entity wants to send an L-byte message to its peer process, using an existing TCP connection. The TCP segment consists of the message plus 20 bytes of header. The segment is encapsulated into an IP packet that has an additional 20 bytes of header. The IP packet in turn goes inside an Ethernet frame that has 18 bytes of header and trailer. What is the bandwidth utilization in terms of the percentage of the transmitted bits in the physical layer corresponds to message information if L = 500 bytes?
- 70%
- 90%
- 80%
- 100%
3. Of the following services, which service(s) does the IP layer provides?
- Error control
- Flow control
- Connection-based data transfer
- None of the above
4. Which of the following is true about the ways in which the OSI reference model and TCP/IP reference model differ.
- TCP/IP model does not have presentation layer, but OSI model has
- TCP/IP model does not have session layer, but OSI model has
- All of the above
- They differ in the number of layers
5. Which of following statements is true about how the data link layer and transport layer differ?
- Data link layer is concerned with framing and the transport layer is not
- Data link layer is concerned with flow control and the transport layer is not
- Data link layer is concerned with multiplexing and the transport layer is not
- All of the above
6. This layer is an addition to OSI model
- Application layer
- Presentation layer
- Session layer
- Presentation layer and Session layer
7. The functionalities of presentation layer includes
- Data compression
- Data encryption
- Data decryption
- All of the above
1. In BSD socket API, which call is usually used for transmitting data in the connectionless mode?
- accept()
- connect()
- sendto()
- None of the above
2. Which of following statement about TCP/UDP sockets is wrong?
- TCP socket is stream oriented
- UDP socket is block oriented
- TCP is faster than UDP
- All of the above
3. Which of following are commonly used as digital communication medium?
- Optical fiber
- All of the above
- Coaxial cable
- Twisted pair
4. Consider a network link that has distance of 100 meters, and signal traverses at the speed of light in cable 2.5 x 10^8 meters per second. The link has transmission bandwidth of 100 megabits/second (100 x 10^6 bits per second). The packet size is 400 bits. What is the signal propagation delay?
- 4 x 10^-7 seconds
- 4 x 10^-9 seconds
- 4 x 10^-6 seconds
- None of the above
5. Consider a network link that has distance of 100 meters, and signal traverses at the speed of light in cable 2.5 x 10^8 meters per second. The link has transmission bandwidth of 100 megabits/second (100 x 10^6 bits per second). The packet size is 400 bits. What is the packet transmission delay?
- None of the above
- 4 x 10^-9 seconds
- 4 x 10^-6 seconds
- 4 x 10^-7 seconds
6. An API allows application programs to access certain resources through a predefined interface?
- True
- False
7. In transport protocol, which of the following statements is true for User Datagram Protocol
- It enables best-effort connectionless transfer of individual block of information
- It enables connection-oriented reliable transfer of individual block of information
- It enables best-effort connectionless reliable transfer of a stream of bytes
- None of the above
8. Which of the following sentences are true for connectionless stream mode of service
- No setup overhead and delay
- Destination address with each block
- Send/receive to/from multiple peer processes
- Multiple write/read between peer processes
9. In transmission delay, in order to reduce the number of bits in a message we use data compression
- True
- False
10. Which of the following is true of data compression algorithms
- Represent the information using fewer bits
- Recover information approximately
- Modify data headers
- Recover original information exactly
1. Given an information polynomial code I(x) = X^7 + x^6 + x^1 + 1, which is its corresponding per-bit information frame?
- 11000011
- 01100011
- None of the above
- 10100010
2. What is the remainder obtained by dividing x^7 + x^5 + 1 by the generator polynomial x^3 + 1?
- x^2 + x + 1
- x^2 + x
- x^2 + 1
- None of the above
3. Given a generator polynomial g(x) = x^3 + x + 1. Consider the information sequence 1001. By CRC method, what is the resulted codeword for transmission?
- 1001000
- 1010110
- 1001110
- 1001111
4. Which of following generator polynomial can detect all single bit errors in an information frame?
- g(x) = x
- g(x) = x^2
- g(x) = x + 1
- All of the above
5. Internet protocols use check bits to detect errors, instead of using CRC polynomial. The primary rationale is
- Strength of error detection capability
- Simplicity of implementation
- CRC polynomial cannot work for Internet protocols
- None of the above
6. The two basic approaches in error control are error prevention and detection, and error correction and re-transmission
- True
- False
7. Find parity bit for 1001011
- 0
- 1
- 2
- None of the above
8. The divisor in a cyclic code is normally called the _________.
- Degree
- Redundancy
- Generator
- None of the above
9. The checksum of 0000 and 0000 is
- 0101
- 1010
- 1111
- 0000
10. In ASCII, a single parity bit code can detect ________ errors.
- An even number of
- No errors
- An odd number of
- Two
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