Q: – What is an object server doing?
With the aid of an object server the application from the client or from the server is a group of communicating objects. The Objects Request Broker or ORB facilitates the communication between client objects and server objects.
Q: – What is the difference between these three: encryption, encoding and hashing?
Encryption is used for keeping data intact and safe and is not so easy to reverse because it requires a certain key. Encoding is used to protect data as it passed through the network and after reaching the destination the data returns to the initial state because it is easy reversible process; being easy reversible makes it not so good for data protection. Hashing is a protection method that is not reversible and the data comes under the form of a string named the hash value.
Q: – How can we explain the following terms: gateway and router?
A gateway is like a door that opens for a data package to exit the interior network and step outside the network. The Router handles the transportation of data packages over the interior network.
Q: – What is the way in which the Asynchronous Transfer Mode works?
The Asynchronous Transfer Mode or ATM is a connection technology that works by transmitting data into organized 53 bytes (small) packages through a physical environment with a high efficiency. Packing data into small cells reduces transportation delay so the speeds reached by this technology are very high; it can reach even 10 Gb per second.
Q: – What types of Transmission media do exist?
The signals transported through Transmission media care have two types:
Guided media
Guided media are the conduit types that allow transmission through coaxial cables, fiber optics and twisted-pairs. In this type of transmission the data flow is dependable of the physical limits of the conducting material. The signal is transported over the metallic conductor as an electric current, this is the case for coaxial cables and twisted pairs. In the case of fiber optics lights signals are transmitted through a plastics or glass cable.
Unguided media
This type refers to wireless communication which uses the air to propagate the signal, along with the cellular phone technology, satellite technology and radio technology. The signal takes the form of electromagnetic waves and travels on the air without the need of a solid conductor.
Q: – What is a broadcast storm?
We say we have a broadcast storm when the traffic or broadcasting on the network has reached certain limits, meaning that it’s overwhelmed and this can make the network loose the connection. In order for the network to be protected against broadcast storm a firewall must be installed.
Q: – How can we explain what a Protocol Data Unit is?
The Protocol Data Unit or PDU is the data unit from the LLC level and has four fields:
a)the source service access point or SSAP
b)the destination service access point or DSAP
c)the information field
d) the control field
The first two are used for finding the protocol stacks by the LLC on the machines that send or receive data, they are addresses. The control field states when a PDU frame is a supervisory or an information frame.
Q: – What difference there is between these terms: RARP and ARP?
RARP or the reverse address protocol determines a host to find the internet address when only a physical address is known. ARP or the address resolution protocol brings together the IP address which is 32 bit with the physical address which is 48 bit. It is used for finding the physical address when the IP is known.
Q: – What is the meaning of FTP and TFTP application layer protocols?
FTP or File Transfer Protocol is the process file transfer between hosts and it’s provided by the TCP/IP. Two connections are made that are secure over the TCP: one for file copying and one for information control. These connections are also called virtual circuits. TFTP or the Trivial Transfer Protocol is using UDP to transfer file form a remote host to a local host but without the advantages of security and reliability.
Q: – Can you give me a list of priorities concerning network support?
Usually a network administrator doesn’t receive a single call when a problem arises. The problems in most cases affect multiple employees so we must learn how to make a list of priorities. The major problems that we must take into consideration are the following:
a)Minor problem- these come from a single user and happen quite often, the user can continue working but with some lacks.
b)Partial failure of a workstation- in this case a single user is affected and almost all the tasks are compromised
c)Small failure of a network- this affects a group of users, not just an individual
d)Partial failure of a network- this has an impact on multiple user groups
e)Total failure of a workstation- in this case an individual can’t work at all
f)Total failure of a network- when everybody gets the problem and nothing works.
Q: – Which are the tools you carry usually for troubleshooting?
A generic question from the interviewer that wants to verify if the flow of the answer remains the same no matter what question is asked, so the details of the answer are not the ones that really count here. The “gear “ of a network admin must include CD-ROM’s, technical support links, networks analyzers, server log files, telephone numbers, README files and so on. Subscriptions to certain support companies are important to be declared.
