Section: Information System Operations, Maintenance and Support
Explanation/Reference:
Error rate is the number of corrupted bits expressed as a percentage or fraction of the total sent
For your exam you should know below information about Network performance:
Network performance refers to measurement of service quality of a telecommunications product as seen
by the customer.
The following list gives examples of network performance measures for a circuit-switched network and one
type of packet-switched network (ATM):
Circuit-switched networks: In circuit switched networks, network performance is synonymous with the grade
of service. The number of rejected calls is a measure of how well the network is performing under heavy
traffic loads. Other types of performance measures can include noise, echo and so on.
ATM: In an Asynchronous Transfer Mode (ATM) network, performance can be measured by line rate,
quality of service (QoS), data throughput, connect time, stability, technology, modulation technique and
modem enhancements.
There are many different ways to measure the performance of a network, as each network is different in
nature and design. Performance can also be modeled instead of measured; one example of this is using
state transition diagrams to model queuing performance in a circuit-switched network. These diagrams
allow the network planner to analyze how the network will perform in each state, ensuring that the network
will be optimally designed.
The following measures are often considered important:
Bandwidth - Bandwidth is commonly measured in bits/second is the maximum rate that information can be
transferred
Throughput - Throughput is the actual rate that information is transferred
Latency - Latency is the delay between the sender and the receiver decoding it, this is mainly a function of
the signals travel time, and processing time at any nodes the information traverses
Jitter - Jitter is the variation in the time of arrival at the receiver of the information
Error Rate - Error rate is the number of corrupted bits expressed as a percentage or fraction of the total
sen
The following answers are incorrect:
Bandwidth - Bandwidth is commonly measured in bits/second is the maximum rate that information can be
transferred
Throughput - Throughput is the actual rate that information is transferred
Latency - Latency is the delay between the sender and the receiver decoding it, this is mainly a function of
the signals travel time, and processing time at any nodes the information traverses
The following reference(s) were/was used to create this question:
CISA review manual 2014 page number 275

Section: The process of Auditing Information System

Section: Protection of Information Assets
Explanation:
The neural networks-based IDS monitors the general patterns of activity and traffic on the network and creates a database. This is similar to the statistical model but has the added function of self-learning.
Signature-based systems are a type of IDS in which the intrusive patterns identified are stored in the form of signatures. These IDS systems protect against detected intrusion patterns. Statistical-based systems need a comprehensive definition of the known and expected behavior of systems. Host-based systems are not a type of IDS, but a category of IDS, and are configured for a specific environment. They will monitor various internal resources of the operating system to warn of a possible attack.

The finding that should be the IS auditor's greatest concern is that the data model is not clearly documented.
A data model is a representation of the structure, relationships, and constraints of the data used by an application. It is a vital component of the software development process, as it helps to ensure the accuracy, consistency, and quality of the data1. A clear and comprehensive documentation of the data model is essential for the maintenance and support of the application, as it facilitates the understanding, modification, and troubleshooting of the data and the application logic2.
If the organization plans to bring the support and future maintenance of the application back in-house, it will need to have access to the data model documentation from the vendor. Without it, the organization may face difficulties in transferring the knowledge and skills from the vendor to the in-house team, as well as in adapting and enhancing the application to meet changing business needs and requirements3. The lack of data model documentation may also increase the risk of errors, inconsistencies, and inefficiencies in the data and the application performance2.
The other findings are not as concerning as the lack of data model documentation, because they do not directly affect the quality and maintainability of the application. The cost of outsourcing is lower than in-house development is a benefit rather than a risk for the organization, as it implies that outsourcing has helped to save time and money for the organization4. The vendor development team is located overseas is a common practice in outsourcing, and it does not necessarily imply a lower quality or a higher risk of the application. However, it may pose some challenges in terms of communication, coordination, and cultural differences, which can be managed by establishing clear expectations, roles, and responsibilities, as well as using effective tools and methods for communication and collaboration5. A training plan for business users has not been developed is a gap that should be addressed by the organization before deploying the application, as it may affect the user acceptance and satisfaction of the application. However, it does not directly impact the quality or maintainability of the application itself. References:
* What is Data Modeling? Definition & Types | Informatica1
* Data Modeling Best Practices: Documentation | erwin2
* Data Model Documentation - an overview | ScienceDirect Topics3
* Outsourcing App Development Pros and Cons - Droids On Roids4
* 8 Risks of Software Development Outsourcing & Their Solutions - Acropolium5
* Software Training Plan: How to Create One for Your Business - Elinext