review answers

please see the comments and modefy the answers to include the missed topics

Individual Comments:

Your answers missed there below topics, spend a little more time on the format of your answers

question 1 – backward compatibility?, scalability?

question 2 – success rate?, reliability?

question 3 – QoS?, Security?

question 4 – foreign agent?

1. Why did Ethernet become an acceptable LAN standard?

Be specific in your explanation.

Many factors funded to Ethernet by becoming a LAN standard, the first factor is that Ethernet is reliable by using CSMA/CD to sense before sending any data to the network to avoid crash, and in this case the crash detection method stop all transmission and assigns a random retransmission delay time to all nodes. The second factor is the management tools that are available to manage the Ethernet using SNMP from a central location. The third factor is Ethernet trouble shooting is easy by using easy ways for example the light indicator or a more sophisticated way like using a network analyzer. The fourth reason is that Ethernet has a low cost comparing it to other technologies that the user doesn’t need to buy extra hardware and can connect it directly depending on his computer network. On the other hand, it doesn’t have a security issue such as wireless networks which has risk through the airwaves, but, users should have good security desktop application to prevent unapproved accesses.

2.From the users point of view how does one measure network performance?

The network performance is identified commonly in bites per seconds. It can be measured by multiple factors which are bandwidth, throughput, latency and error rate and from those factors the bandwidth is the maximum rate that data can be transferred with, Latency is the delay between the sending and receiving. Error rate is the percentage of corrupted data that is being sent. There are three main possible ways to measure: the first one is the total of bytes transferred (from server to the user and opposite) in one session which can be used to measure the overhead of protocol (bandwidth). Second ways, number of round trips in one operation (transaction). Third point, time taken to pull or push from network bandwidth and ping time. Moreover, the user could measure network performance in normal way by trying to copy a file over the network depending on the file transferring time; furthermore, he could gauge the speed by the time it takes for a file to copy from or to the network.

3.Why did IPv4 prevail for such a long time and why the change to IPv6?

Shifting for IPv4 to IPv6 requires a huge investment of human and capital resources. While, it doesn’t provide a clear picture of the short-term return which resulted the enterprises to frequently postpone this investment. However the time came to change from IPv4 to IPv6. IPv4 provide maximum of about 4 billion addresses whereas IPv6 has an unthinkable theoretical maximum: about 340 trillion, trillion, trillion addresses. Previously (with IPv4) home user got a single user, while the IPv4 provides blocks of addresses sufficient to number multiple networks and thousands of devices. Moreover, Enterprises and small businesses will generally be given enough to number a substantial number of networks and tens of thousands of devices; while larger sites will get significantly even more.

4.How does IP solve the user wireless mobility requirements when entering to a different network cell?

The mobile IP allowed users to move from one network to another while maintaining the same IP address. Each node is identified by its home address without looking at its location.

Moreover, node must recognized and located on the network directed by its IP address in order to receive datagrams, so, when moving to different networks the IP protocol does not allow the current IP address to be valid in the visiting network. In this case a scheme must be provided to allow nodes to maintain and reach the connections while moving.