CS610 - Computer Network
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Q & A
Short Question & Answers
Q1: Where are destination and source address located in frame?
The packet header includes destination and source addresses.
Q 2: If 100mbps Ethernet NIC is connected to a hub which supports 10mbps, what will be the data rate in this scenario?
This has two consequences. First, the hub does not necessarily create a broadcast medium. Second, there are no collisions between traffic on 10 Mbps ports and 100 Mbps ports.
Q3: In connection oriented network, which type of connection identifier is used? Support your answer with example.
ATM uses the concept of connection-oriented networking.
Q4: Is there a comparison between TCP/IP reference model and OSI reference model?
Both the TCP/IP and OSI are international standards for data communication. Both use the concept of protocol layering. These are the conceptual tools that is often used to show how various protocols and technologies fit together to implement networks. The functions that the model represents are much the same. This means that the TCP/IP and the OSI models are really quite similar in nature even if they don't carve up the network functionality pie in precisely the same way. There is a fairly natural correspondence between the TCP/IP and OSI layers; it just isn't always a “one-to-one” relationship. Since the OSI model is used so widely, it is common to explain the TCP/IP architecture both in terms of the TCP/IP layers and the corresponding OSI layers
Q5: Network administrator needs audio and video service for his network. He has to send or receive data at same data rate. Which type of ATM quality service specification would be applied there? Give example?
To facilitate the transport of audio and video data across emerging Asynchronous Transfer Mode (ATM) networks, a simple, low cost, audio/video ATM appliance, the AVATAR, has been developed. This appliance is capable of handling uncompressed bidirectional audio and NTSC video connections.
Q6: We have two satellite locations, at first location one bridge is configured and at second location 2 bridges are configured. Which location performed will be faster? Give reason.
Satellite locations with two bridges configured will performed faster. The brigade also had to provide power to virtually all of its East Timor assets. Setting up the satellite system, for example, required supplying power to both the communications station and the users’ computers. A bridge that has multiple ports is known as a networking switch. Both bridges and switches are capable of directing traffic to specific network addresses instead of broadcasting the data to all devices on a network segment. This functionality makes the bridge or switches a more advanced networking device over a hub or repeater.
Q7: There are two sites office A & B, both are using VPN. If a user of another network wants to send some packet to A, then what will be the behavior of network A? How data is protected in VPN environment?
In theory when a machine on private network A wants to send a packet to a machine on private network B the packet is accepted by the VPN server. It is then encrypted and encapsulated within a standard IP packet that has a destination address corresponding to the VPN server at network B. Notice that both VPN servers have to have to be “on the Internet” in the sense of having publicly accessible IP addresses. When the packet arrives at network B’s VPN server it extracts the encapsulated private packet, decrypts it and sends it on its way within the local network. The machines within network A and B don't have to have publicly accessible address - that is they don't have to be on the public Internet. This way of using the public Internet to connect two machines that are not on the public internet is another advantage of the VPN approach. As far as users of network A and B are concerned the VPN is as good as a dedicated physical connection. The idea of using public data packets to transfer embedded private data packets is often called “tunnelling” because it seems to create a data tunnel between the two networks.
Q8. Star Textile has huge network of systems and switches. A task is given to IT Officer that if some link goes the entire network works smoothly. Which routing method will be use?
Distributed routing method is better for this purpose because Distributed routing relies on each node to compute its own routing table and build the required connections with its neighbors. Ideally, the network operation, status, and architecture of each node is transparent. Distributed routing is more flexible than centralized routing because each node handles its own routing. The result is often improved system performance.
Q9: Network administrator wants to build a tunnel between sites offices. How will he build using private virtual network?
To establishes a private network that can send data securely between these two locations or networks through a "tunnel." A VPN tunnel connects the two PCs or networks and allows data to be transmitted over the Internet as if it were still within those networks.
Q10: Who examine performance of network?
Performance is probably the most closely monitored operational feature by users in the network environment.
Q11: How can we compute shortest path in WAN?
We use Djikstra’s algorithm to compute shortest path from each node to every other node.
Q12: What type of switching technique is used in WAN?
WANs can use circuit-switching or packet-switching techniques. To span long distances or many computers, networks must replace shared medium with packet switches. Each switch moves an entire packet from one connection to another. That’s why they are called packet switches.
Q13: What type of topology used in Ethernet?
Traditional Ethernet employs a bus topology, meaning that all devices or hosts on the network use the same shared communication line.
Course Instructor

Mr. Hammad Khalid Khan
M.S Electrical Engineering
Oklahoma State University USA

Computer Networks & Internets with Internet Applications by Douglas E.Comer

Computer Networks by Andrew S. Tanenbaum

Networking: A Top-Down Approach Featuring the Internet by James F. Kurose and Keith W. Ross