Networking Protocols

Networking Protocols

Question 1:

What is meant by a “nondeterministic” protocol? Give an example.

The probability for a network to assure information "throughput" is defined as determinism. A deterministic network has an assured highest delay of time for transfer of data from node to node, on the contrary a non deterministic network does not. The practical example of a non deterministic network system is Ethernet, where the nodes depend on time of delay circuits to realign and re-perform data transmission following a collision. Knowing that a transmission from node of data can be delayed infinitively, from a long series of retries and resets after repeated collisions, without any surety that its information will ever get transferred out of the network. Though, in reality the odds are so astronomically huge that such a thing would occur that it is of little actual concern in a less loaded network (All about circuits, 2012).

Question 2:

Your wireless LAN device has just sent a request to send (RTS). What happens next?

The wireless LAN device has just sent a request to send (RTS). To avoid collisions in these conditions, CSMA/CA gives permission to devices to reserve the channel of transmission for some period. This is made by utilizing two frames of control: Request To Send (RTS) and Clear To Send (CTS). Both of these are very small frames to minimize the collisions risk. To occupy the transmission channel, a device transfers a RTS frame to the desired recipient of the data frame. The RTS frame contains the duration of the requested reservation. The recipient replies, after a SIFS delay, with a CTS frame which also contains the duration of the reservation. As the duration of the reservation has been sent in both RTS and CTS, all hosts that could collide with either the sender or the reception of the data frame are informed of the reservation. They can compute the total duration of the transmission and defer their access to the transmission channel until then. This is illustrated in the figure below where host A reserves the transmission channel to send a data frame to host B. Host C notices the reservation and defers its transmission (Computer Networking, 2013).

Question 3:

Your company wants to create a wireless network for the entire office building. The building is 10 stories high, and the company wants to incorporate IEEE 802.11a by placing one access point on the tenth floor. Will this layout work? Explain.

No, this layout will be definitely not going to work as the coverage of IEEE 802.11a called a Wi-Fi covers the space in all directions within its surroundings. But, the coverage has a specific range of less than 100 meters. From tenth to ground floor the distance is comparatively larger. Secondly the signals will get weak and distorted by the material used in the construction of the building as well as other office wares which play a significant role in distorting the signals. Hence, by any means using a single access point will definitely not going to work in this ...