1. Explain the cirumstances under which a token-ring network is more effective than an Ethernet network.
Ring topology uses token ring i.e one way communication which passes the token with header and Destination address into the network.If one client in the network just disconectd from the network then the the entire network collapse.
For this problem FDDI is used for fault tolorence
Where as ethernet works much efficiently in packet delivering
2. Although security issues were not mentioned in this chapter, every network owner must consider them. Knowing that open networks all data to pass to every node, describe the posssible security concerns of open network achitectures. include the implicatiions of passing logon procedures, user IDs, and passwords openly on the network.
There are at least three sides to security.
• Technical – Passwords, security cameras, quantum communications, biometrics, etc. etc.
• Institutional– Human resources, analytic tools…
• Social– How life experience influences behavior of the population
•Implications
- Not controlled by anybody
- No privacy –email is a postcard
- Duplication is easy
- Don’t know who’s on the other end of the line
3. Remembering the discussion of deadlocks, if you were designing a networked system, how would you manage the treat of deadlocks in your network? Consider all of the following: prevention, detection, avoidance, and recovery.
• Simulate the most favored execution of each unblocked process. An unblocked process may acquire all the needed resources. Released resources may wake up some previously blocked process. Recovery by process termination. Terminate deadlocked processes in a systematic way when enough processes terminated to recover from deadlock, stop terminations. Each process must request and acquire all the needed resources at the same time. Avoiding it requires a process to declare the maximum instances of each resource type needed, upon request, the system must determine whether the allocation will leave the system in a safe state considering the number of processes in the system and number of resource classes.
4. Assuming you had sufficient funds to upgrade only one component for a system with which you are familiar, explain which component you would choose to upgrade to improve overall performance, and why?
