Exercise 1 (31.10. - 4.11.)

1. Bits, binary numbers and power prefixes

   1. If an identification field is 8, 16 or 32 bits long, how many different items can be identified using it?
   2. Show the decimal number 246 as a binary number and as a hexadecimal number.
   3. Show the binary number 101101101 as a decimal number and as a hexadecimal number.
   4. Do the addition of three binary numbers: 10010011, 10101010 and 01110111.
   5. How large is a nanosecond, one terabit per second, one picometer and a petabyte?

2. Terms and meanings (Terms and their meanings you can find in the course book or in the web)
   Explain with your own words what is meant by the following terms.
   1. protocol, service
   2. packet, message
   3. host, router, link-layer switch
   4. internet, intranet, extranet
   5. client, server
   6. store-and-forward

3. Lost, multiplied and delayed packets
   Can a packet in data communication networks get totally lost, be multiplied or arrive to the receiver very much (even days) delayed. If it can then explain how.

4. Different networks and their advantages and disadvantages (Explained in the course book and in the web)
   What is meant by circuit switching and packet switching? What are the advantages and disadvantages of packet switched networks when compared with circuit switched networks?

5. Transmission rate (bps): Cyclist example
   1. A cyclist carries four 4 Gbyte memory sticks and five double sided 8.5 Gbyte DVDs.The speed of the cyclist is 18 km/h. To what distances does the cyclist transmit information faster than a line of i) 9600 bps, ii) 384 kbps, iii)24 Mbps or iv) 1 Gbps?
   2. Couldn't we just use brisk cyclists, each with a big bag of DVDs, to take care of large amount of data communication? What are the benefits and drawbacks of this kind of information transmission? To what kind of situations does it fit well, to what very badly?

6. The learning goals for the course
   

   1. What do the different columns in the Learning Goals Scheme mean?
   2. What already familiar network techniques do you find in the Learning Goals Scheme?
   3. Which network techniques mentioned in the Learning Goals Scheme are in use in the Internet?
   4. What are the layers of the Internet protocol stack? To which layers this course seems to give more importance, to which layers less?
   5. What Internet applications seem to be part of the course? What Internet applications do you use or what have you used?