Computer Networks Answers

Consider a system with 14 dedicated devices of the same type. All jobs currently

running on this system require a maximum of five devices to complete their

execution but they each run for long periods of time with just three devices and

request the remaining two only at the very end of the run.

Assume that the job stream is endless and that your operating system’s device

allocation policy is a very conservative one: No job will be started unless all the

required drives have been allocated to it for the entire duration of its run.

a. What is the maximum number of jobs that can be active at once ?

List all the steps of a DNS lookup for www.iie.ac.za

The use of virtual memory:

a. Results in faster execution speeds

b. Creates the illusion that a computer has more main memory than it in fact has

c. Ensures disk space is used efficiently

d. Ensures that all programs are relocatable

Using the maximum likelihood method, adjust a power law distribution to the degree

distribution of your network and test the quality of the result by calculating the root mean square

error between the estimated and the actual degree distribution. Write down explicitly the

expression for the adjusted power law.

Describe the nature of the network by explicitly indicating what kind of objects are its

nodes and their number, what kind of relation the links represent and their number, and what actual

function does the network represent.

Department Number of Users

Customer Care 10

Sales and Marketing 20

Finance 25

Legal 5

HR 10

Developers 55

Network Team 5

Server Room

Servers +ISP connections

·   All the departments must be separated with unique subnet and should not communicate with each other unless there is a special requirement.

·   IPs should assign using DHCP.

·   ERP and CRM Systems need to be implemented in this in local servers.

·   Number of servers required for the Server room need to be Uses static IPs.

·   High level of redundancy is expected in network design to eliminate single point of failures and traffic bottle necks.

·   Sales and Marketing need to access Network resources using WIFI connectivity.

·   Proper methods for networking monitoring and troubleshooting need to be established.

·   All possible network security mechanisms should be implemented.

·     Prepare a written network design plan to meet the above mentioned user requirements including a blueprint drawn using a modeling tool. (Ex: EdrawMax).

Department Number of Users

Customer Care 10

Sales and Marketing 20

Finance 25

Legal 5

HR 10

Developers 55

Network Team 5

Server Room

Servers +ISP connections

· High level of redundancy is expected in network design to eliminate single point of failures and traffic bottle necks.

· Sales and Marketing Team need to access Network resources using WIFI connectivity.

· Proper methods for networking monitoring and troubleshooting need to be established.

· All possible network security mechanisms should be implemented.

 1.Prepare a written network design plan to meet the above mentioned user requirements including a blueprint drawn using a modeling tool. (Ex: Microsoft Visio, EdrawMax).

2.Support your answer by providing the VLAN and IP subnetting scheme for the above scenario and the list of devices, network components and software used to design the network for above scenario and while justifying your selections.

Department Number of Users

Customer Care 10

Sales and Marketing 20

Finance 25

Legal 5

HR 10

Developers 55

Network Team 5

Server Room

Servers +ISP connections

· High level of redundancy is expected in network design to eliminate single point of failures and traffic bottle necks.

· Sales and Marketing Team need to access Network resources using WIFI connectivity.

· Proper methods for networking monitoring and troubleshooting need to be established.

· All possible network security mechanisms should be implemented.

Recommend suitable network topologies for above scenario and justify your answer with valid points. (with using the brief)

Discuss the following physical media characteristics:

1. Throughput (6 Marks)

2. Cost (6 Marks)

3. Noise immunity (6 Marks)

4. Size and scalability (6 Marks)

5. Connectors and media converters (6 Marks)

Models are useful because they help us to understand difficult concepts and complicated systems. When it comes to networking, there are several models that are used to explain the roles played by various technologies and how they interact. The most popular and commonly used of these models is the Open Systems Interconnection (OSI) Reference Model. Discuss the OSI model in terms of the functions of the various layers that it is made up of. Make use of a diagram to explain the various layers.