Sec 435 Network Management: Connection Assessment Answers

1).

Give two example computer applications for which connection-oriented service is appropriate. Now give two examples for which connectionless service is best.

2).

Both UDP and TCP use port numbers to identify the destination entity when delivering a message. Give two reasons why these protocols invented a new abstract ID (port numbers), instead of using process IDs, which already existed when these protocols were designed.

3.

In the above diagram, router interfaces are included in the number of hosts. For example, Network C is listed as having 2 hosts. Both of these hosts are router interfaces.

3a) Using the network diagram provided above, apply a classical subnetting (NO VLSM and equal size subnets) to create a network scheme using a single private class C network range. List the

Network address, Broadcast address, netmask and Router Interface(s) addresses for each network.

3b) Using the network diagram provided above, use VLSM to create an optimized network with a private class C address. List the Network address, Broadcast address, netmask and Router Interface(s) addresses for each network. Justify your network design. (why did you choose the sizes you did?

4).

Under what conditions of delay, bandwidth, load, and packet loss will TCP re-transmit significant volumes of data unnecessarily?

1.

• The connection oriented service is defining as a transmission control protocol for communicate end to end device data transfer. Therefore, the example of connection oriented services is video on demand and file transfer.
• The connection less services are electronic fund transfer and credit card verification.

2.

1. The reason behind generating new abstract ID instead of process ID is not static. However, process ID is assigned dynamically whenever a new process is generated. Therefore, it is never used for ant HTTP process.
2. If any certain scenario, one process may manage multiple sockets on various TSAPs, if process ID is being used for this situation, then it cannot be initiated since one process is assign with one process ID.  

3. A

 3.B

 4.

TCP protocol re-transmitted to significant volumes of data unnecessarily due to longer retransmission timeout (RTO) and acknowledgment of transmitted message is received. However, a retransmission is occurring at the moment when RTT estimators cannot be updated till the acknowledgement for retransmitted data is arrived. This problem is known as retransmission ambiguity problem, which causes TCP re-transmission of significant data. Another cause of re-transmission is occurring when a TCP sender observe that fast retransmit threshold is too low as well as reordering in the network.    

Bibliography

Hwang, J., Walid, A. and Yoo, J., 2016. Fast Coupled Retransmission for Multipath TCP in Data Center Networks. IEEE Systems Journal.

Jain, M., Tomar, D.S. and Singh, S.K., 2015. A Survey on TCP Congestion Control Schemes in Guided Media and Unguided Media Communication. International Journal of Computer Applications, 118(3).

Moiseenko, I. and Oran, D., 2016, September. TCP/ICN: Carrying TCP over Content Centric and Named Data Networks. In Proceedings of the 2016 conference on 3rd ACM Conference on Information-Centric Networking (pp. 112-121). ACM.

VanHeyningen, M.D. and Erickson, R.D., Aventail Llc, 2016. Method and apparatus for providing secure streaming data transmission facilities using unreliable protocols. U.S. Patent 9,467,290.