What is Dynamic synchronous transfer mode (DTM)?

Dynamic synchronous transfer mode or the DTM is a technology developed for optical networking. The ETSI (i.e., the European telecommunications standards institute) standardized this technology in the year of 2001 marked with the following beginning specification ‘ETSI ES 201 803 – 1’. 

This is a circuit switching network technology that doubles as a time division multiplexing technology too. Actually, this technology is built up on a combination of the switching and transport.

This technology guarantees to provide QoS or quality of service for services that are involved with the streaming of videos. 

However, it might be used for packet – based services also. It is marketed for the following:

1. Professional media networks
2. Mobile TV networks
3. DTT or digital terrestrial television networks
4. Content delivery networks
5. Consumer oriented networks (for example, triple play)

What is Switching?

- Switching of the channels is specified by DTM. 

- This is what that makes it different from the other transmission techniques that we have, for example, SONET (synchronous optical networking), SDH (synchronous digital hierarchy) and so on. 

- End to end provisioning is done for the DTM channel over a network with general topology through the use of control signaling.

- DTM therefore represents a circuit switched system. 

- The switches are nothing but time space switches that guarantee the QoS property. 

- The allocation of the resources is done physically for each channel in the switch. 

- This is quite contrary to the switches that are based up on packets or cells. 

- In those kind of switches there is always a competition for resources between the packets and cells. 

- Such a competition leads to delaying and discarding of the packets and cells. - Other methods offer a shared resource allocation mechanism that draws a limit for the packet and cell switches regarding their utilization of the network in such way that the QoS is maintained at a certain level. 

- But DTM does not follow this shared allocation mechanism rather it implies that a network can be loaded up to full limit theoretically and still can guarantee the QoS. 

- Thus, here real utilization is more like a question of adaptation of the network topology as well as its link capacities considering the actual traffic matrix.

- Packet and cell based switching technologies are more suited to statistical multiplexing.

- It means whenever a packet streams in a router come at an outgoing link that is common to all of them, buffering is carried out until the resources are free on that particular link.

- In this way, it becomes possible to make use of the outgoing link to the maximum degree possible without causing many delays. 

- This also proves fitting for the best effort traffic. 

- But there are certain QoS requirements of the streaming media that cannot be ignored. 

- Streaming traffic is by nature not statistical and therefore is better maintained by end to end resource allocation.

- This category is applicable for audio and video services.

- This is not exclusive of the IP traffic gained via guaranteed QoS transport if majority of the content is audio and video. 

- Some other technologies such as that of IP and Ethernet were also adopted for the same purpose. 

- Multi protocol label switching or MPLS can be applied to the carriage network for improving the reliability as well as determinism that is required by most of the streaming media. 

- This technology is applied along with the techniques such as the forward error correction.

- Ethernet has been made supportive for audio and video transmission by improvement in technologies such as the provider backbone bridge traffic engineering. 

- The development of dynamic synchronous transfer mode took place at the royal institute of technology. 

What are Software Process Improvement resources?

A supportive and effective infrastructure is required for facilitating the coordination of various activities that place during the course of the whole program. In addition to these qualities the infrastructure should be quite flexible so as to be able to support the changing demands of the software process improvement with time. 

Resources for this program include:

1. Infrastructure and building support
2. Sponsorship
3. Commitment
4. Baseline activities
5. Technologies
6. Coordinate training resources
7. Planning expertise
8. Baseline action plan and so on.

- When this program is initiated, a primitive infrastructure is put in to place for the management of the activities that would be carried out by the organization under SPI. 

- The resources mentioned above are also the initial accomplishments that tell how well the infrastructure has been performing. 

- It is the purpose of the infrastructure to establish a link between the program’s vision and mission, to monitor it and guide it and obtaining resources and allocating them.

- Once the SPI program, a number of improvement activities will be taking place across the different units of the organization. 

- These improvement activities cannot be performed serially rather they take place in parallel. 

- The configuration management, project planning, requirements management and reviews etc. are addressed by the TWGs (technical working groups). 

- But all these activities are tracked by the infrastructure.

- Support for the following issues must be provided by the infrastructure:

1. For a technology that is to be introduced.
2. Providing sponsorship
3. Assessment of the organization impact

- As the program progresses, the functions to be performed by the infrastructure increase. 

- There are 3 major components of the SPI program:

1. SEPG or software engineering process group
2. MSG or management steering group
3. TWG or technical work group

- It is third component from which most of the resources are obtained including:

1. Human resources
2. Finance
3. Manufacturing
4. Development

- However, the most important is the first one and is often called the process group. 

- It provides sustaining support for the SPI and reinforcing the sponsorship. 

- The second component i.e., the MSG charters the SEPG.

- This is actually a contract between the SEPG and the management of the organization. 

- Its purpose is to outline the roles and the responsibilities and not to forget the authority of the SEPG. 

- The third component is also known as the process improvement team or process action team. 

- Different work groups created focus on different issues of the SPI program. 

- A software engineering domain is addressed by the technical work group. 

- It is not necessary for the TWGs to address the technical domains; they can address issues such as software standardization, purchasing, travel reimbursement and so on. 

- The team usually consists of the people who have both knowledge and experiencing regarding the area under improvement. 

- The life of TWGs is however finite and is defined in the charter. 

- Once they complete their duties, they return back to their normal work. 

- In the early stages of SPI program, the TWGs might tend to underestimate the time that would be required for the completion of the objectives assigned to them. 

- So the TWGs have to request to the MSG for allotting them more time. 

- Another important component could be the SPIAC or software process improvement advisory committee. 

- This is created in organizations where there are multiple functioning SEPGs. 

Explore Test Director Window, Test Director Modules and elements?

The test director is a web based application and it provides well support to communication of a very high level. Further, it regulates collaboration between the testing teams which are widely distributed. Overall, it helps in driving a global application testing in a more effective and efficient manner. 

Being the global test management tool, it is also counted in the list of the industries’ best test management solution.

Features of Test Director

Test director comes with a whole lot of features to make software testing a better experience:

1. Web based site administrator
2. Domain management
3. Collaboration module
4. Advanced reports add – in
5. Automatic trace-ability notification
6. Hierarchical test sets
7. Work flow for all modules of the test director
8. User industry standard repositories
9. Link test plan to requirements
10. Integrates with MS office
11. Manages automated and manual tests
12. Accelerates testing cycles
13. Supports test runs across boundaries
14. Integrates with third party and internal tools
15. Structured information sharing
16. Easy defect reporting
17. Customization reports
    

Here we shall about the following:
1. Test director window, 
2. Elements and 
3. Test director modules.

Test director helps in the following tasks:

1. Organizing and managing all the phases of testing.
2. Specifying the test requirements
3. Planning tests
4. Executing tests
5. Tracking the defects and so on.

- The test director launched from one’s web browser by requesting the url of the test director. 

- When you enter this URL and press enter the test director window pops up.

- If you are running the test director, it will take some time to get downloaded in your system. 

- Whenever the test director is launched a version check is automatically carried out and the latest version is downloaded. 

- Once done with this, you will get a test director log-in window. 

- Now you select a domain among the list of domains provided by the test director or you can select default. 

- In the project list go for testdirector _ demo. 

- You need to log-in as a QA tester. 

Test Director Modules

- In the test director window click on the requirements tab. 

- This requirements tab represents the requirements module which enables you to define the test specifications which includes the following things:

1. Defining purpose of testing
2. Defining requirement topics
3. Analyzation of the requirements

- Similarly, the test plan tab represents the test plan module which powers you to create a test plan based on the requirements specified above. This module facilitates the following tasks:

1. Defining goals and strategies
2. Dividing the plan into categories
3. Development of  the tests
4. Analyzation of the plan.

- With the test lab module the tests can be run on the software system or application and the result can be analyzed. The defects module you can carry out the following tasks:

1. Add the defects
2. Determination of the repair properties
3. Repair of the open defects
4. Analyzation of the data

Elements of Test Director

Now coming to the elements of the test director, there are some elements that are common to all the test director modules and these are:

1. Test director tool bar
2. Menu bar
3. Module tool bar
4. Tools button
5. Help button
6. Log out button

All of these elements can be found in the top level of the test director window. Module tool bar consists of the buttons for the commands that are frequently employed in the current module. 

What are file types used in Silk Test?

Silk test consists of many file types which have been discussed in this article. There are various types of files that are used by the silk test in the process of automation testing. 

Each of the files is used for a specific purpose or we can say function such as certain files are required by the silk test for the creation and execution of the tests. 

Now we shall discuss the different file types available one by one:

1. Test plan (.pln): This file type in silk test facilitates the creation of the test suites. But the test suites can be created lonely if this file type is combined with the test scripts.

Testone

          Script: test.t

          Test case: one

Testtwo

          Script: test.t

          Test case: second

Here in the above example the main test script file is test. t. on the other hand the ‘one’ and the ‘second’ are the names of the test cases in the main script file test.t. Whenever this file type is run the test cases one and second are automatically picked up by the main script file and executed.

2. Test script (.t): This file type in the silk test is used while writing the actual test scripts. Whenever such a file is in run session the test one and test two test cases are executed by it in a predefined order and at the end the note pad application is closed.
3. Frame file (.inc): The windows and the controls present in the AUT or application under test are defined by an abstraction layer. These windows as well as the controls are referenced later in .t files.
4. Result file (.res): This file type consists of all the test run results which have the names of all the passed as well as failed tests along with their suitable descriptions. These file types may or may not contain log messages.

Leaving out the result file (.res) type, almost all the other file types are based up on text. Therefore, the editing of all those files can be edited either using the silk test IDE or by using a text editor.

In the silk test version that was released in the year of 2006, the files can be saved in either of the two formats namely:

1. ANSI format or
2. The UTF – 8 format

5. Project (.vtp): This file type is saved with an extension of 'verify test project' and is used as storage for the locations as well as the names of the files that are currently in use by some project. With this file type there is another associated file type .ini extension since it is an initialization file.
6. Data driven script (.g.t): This file type stores the data driven test cases which are use to pull out data from the data bases.
7. Suite (.s): With the help of this file type the sequential execution of several test scripts is possible.  
8. Text file (.txt): This is an ascii file type and can be used for the following purposes:

a)   For storing a data that can be used for driving a test.

b)   For printing a file in some another document.

c)   The test automation file is accompanied by this file type as a read me file.

d)   For transformation of a tab delimited plan in to a silk test plan.

Entire above discussed source files are compiled and stored as the ‘pseudo code object files’ at either of the times:

1. When the files are loaded or
2. When any change has occurred in the file types. 

What are the different types of Test Automation Frameworks?

Test automation frame work has got its own importance in the field of software testing. It can be defined as a set that consists of concepts, tools and assumptions that can be used to support the automated software testing. The basic advantage of using a test automation frame work is that maintenance costs are reduced by large margins. If any changes to the test case are made then there is a need to update only the test case files. No updates are to be made to the following two scripts:

1. Startup script and
2. Driver script

In some ideal cases there is no need of even updating the scripts in case changes are made to the application software. In order to have all the advantages of using a test automation framework it is important that you select the right one otherwise you will face the problem the other way round. 

There are various frame work techniques that are used namely:

1. Key word driven

2. Data driven

3. Structured

4. Linear

5. Hybrid and so on.

Purpose of Test Automation Framework

1. Defining of format for expressing the expectations
2. Creation of a mechanism for driving the application under a particular test.
3. Execution of the tests
4. Reporting of the results.

A test automation frame work consists of the following four components namely:

1. Test automation interface
2. Interface engine
3. Interface environment
4. Object repository

Types of Test Automation Frameworks

1. Ad-hoc test automation framework: 

- The scripting involved in this is developed in reactionary mode with the purpose of testing a single issue only. 

- The test case steps form part of each action script and exhibit low re-usability and call for high maintenance. 

- This frame work consists of some data inputs that are stored in the data sheet of the test script.

2. Data driven test automation frame work: 

- In this framework the scripts are considered to be an assembly of the function calls. 

- Data for the tests is supplied from the external source such as ODBC database, spreadsheets and so on. 

- Results are captured externally for each script separately.

3. Keyword driven test automation frame work: 

- A sequence of the key word prompted actions are used to be express the test cases. 

- Action scripts which serve the purpose of calling functions are executed by the driver script. 

- For this frame work no special scripting knowledge is required.

4. Model driven test automation framework: 

- This test automation framework makes use of descriptive programming for testing the dynamic applications inclusive of the web applications and sites. 

- The parametric code defines the objects and the work flow capabilities are enhanced by the custom functions.

5. 3^rd party test automation frame work like HP’s quick test professional: 

- This test automation frame work is also key word driven but its control is taken by the HP quality center data base. 

- It can be used in projects where there is a requirement for collaborative work efforts. 

- This framework has high level test requirements and the tests are defined as scripted components.

6. Intelligent query driven test automation frameworks: 

- This framework is object oriented and works on the agile principles. 

- It was constructed as a series of framework layers which compiles data at the run time with the help of data mining techniques which can be combined based up on the cope of the requirements of the test.

What is split action and the purpose of using this in QTP?

Well, here is another article that talks about what is meant by split action and what purpose does it has to serve in test automation using quick test professional. 

In quick test professional, after recording of an action it has to be split in to various parts. This is known as split action. 

In quick test professional two types of split actions have been provided as mentioned below:

1. Splits independent to each other and
2. Nested splits

- After the recording is complete, it is run and designed the option “keyboard view” is selected and the part to be highlighted is clicked. 

- After this the “split action” option is selected from the step menu for splitting the action. 

- Before you decide to split, you should always remember that once you split the action, it cannot be undone. 

- Your original recorded action will be lost and you won’t be able to recover it. - Therefore, to avoid such kind of situations it is important that the recorded action must be saved the very before splitting it. 

- Saving before splitting is always recommended.

- In some cases multiple split actions that are independent of each other can be obtained. 

- There are several advantages of split action:

1. With the actions tests can be divided in to business processes and logical units.
2. With actions quite a modular and efficient scripts can be created.
3. Multiple actions can be contained within a test script.

- The action that is stored in the test scripts that you recorded can be split either in to parent child nested actions or in to sibling actions. 

- Whenever you split an action the beginning of the other part of the action takes place from the step that was selected during the process of splitting the action. 

- You cannot split an action under following situations:

1. If you already have an external action in selection.
2. You have selected the first step of an action.
3. Some read only test is active.
4. Running a test
5. Recording of a test is in progress.

- Some tests make use of a local repository and so while splitting actions contained in such tests following things happen:

1. A copy of local repository is created by the quick test professional.
2. The two action splits are assigned the identical local object repositories. Such local repositories consist of all the objects that were present in the original local object repository.
3. If the objects are added to only one of the split actions, those objects are added to the local object repository of that action only.

- To split an action you need to select the particular step before which according to you lies the starting of the second action. 

- Now, go to the edit menu, the action, and then to split action. 

- Up on clicking on this option you get a split action dialog box. 

- Select the type of actions you want to have i.e., independent or nested. 

- Here, you can also modify the names and description of the two actions in their respective names and description boxes. 

- One important point that you should always take care of is that if you call a reusable action through another test, splitting such an action will cause the test to fail.

Basic purpose of Split Action

- The basic purpose the split action serves is that it makes the application reusable. 

- The reusability is increased since the actions are divided based up on their functionality. 

- Another point is that calling an action is same as asking to execute it and only reusable functions can be called. 

What is the difference between winrunner and test director?

The winrunner is often confused with the test director. But both of them have considerable differences between them. In this article we shall explore the differences between the winrunner and the test director. We shall list all the differences below:

Difference #1:

The winrunner is an automated testing tool that was developed as a functional testing tool by the HP (hewett Packard) whereas the test director is a test management tool. The former tool tests the software system or application while the latter one manages all those tests that are to be performed.

Difference #2:

The winrunner tool only helps in carrying out the tests on the software systems and applications whereas the test director organizes the whole test process as it name says the “test director” much in the way that a film director directs the shoot of the movie. In some cases the test director has also helped in the creation of the test cases.

Difference #3:

Winrunner is a tool that serves the purpose of the automated testing and is mostly used whenever the testers have to carry out any one of them:

a)   Regression testing or

b)   GUI testing

One plus point of the winrunner is that the testing carried out with its aid is quite efficient, fast and reliable. On the other hand the test director is a web based tool for the purpose of management of the tests. In test director, the management of the following takes place with the use of a centralized data base:

    a)   Requirements documentation

    b)   Specification documentation

    c)   Test plans

    d)   Test cases

    e)   Defect managing and

    f)    Defect tracking etc.

Both are completely different tools that have been developed by the same pioneer mercury interactive.

Difference #4:

One of the fact about winrunner is that it can only create automated test scripts and does not has the ability to handle the already automated test scripts. On the contrary, the test director or TD (as you say) forms a kind of central repository for storing the information related to bugs and their management.

Difference #5:

It won’t be wrong to call the winrunner a regression testing tool or a record and play back tool whereas the test director being a test management tool can even help you in the execution of the pre- automated test scripts through a special environment called test director environment.

Difference #6:

The speciality of the winrunner lies in automation of the scripts whereas the test director excels in the field of defect tracking and management.

Difference #7:

Winrunner is used for the following:

a)   Complex Functional testing

b)   Complex Regression testing and

c)   Automating the test scripts

The test director is used for the following purposes:

         a)   Creating the test plans

         b)   Preparing the test cases

         c)   Executing the test cases

         d)   Generating the bug reports

         e)   Maintaining the test scripts and so on. 

Difference #8:

The winrunner is a testing tool that has eased the complexity which is faced by many of the testers during regression testing. On the other hand the test director is a management tool holds the responsibility for keeping a perfect and clean record of the software testing process right from the requirements phase to the end of the testing phase.

Difference #9:

With the help of winrunner the TSL scripts can be recorded and updated and replayed a number of times as and when required whereas with the aid of the test director one can even run the winrunner as well as loadrunner scripts on a remote computer system. 

How can data caching have a negative effect on load testing results?

It is quite a heavy task to retrieve data from a certain repository if we see it through a performance point of view. It becomes much more difficult when the data repository lies too far from the application server.Retrieving data becomes difficult also when a specific type of data is accessed over and over again. 

Caching is a technique that has been developed as a measure for reducing the work load and the time consumed for retrieval of the data. 

In this article, we have discussed about the negative effects that simple data caching can have up on the load testing. 

Rules for Caching Concepts

Some rules have been laid down for the caching concepts which have been mentioned below:

1. The data caching is useful if used only for a short period of time and does not works when used through the life cycle of the software system or application.

2. Only that data which is not likely to be changed quite often should be cached.

3. There are certain data repositories that have the capability of supporting the notification events in case if the modification of the data takes place outside the application.

If these above stated rules are not followed properly, the data caching is sure to have a negative impact up on the load testing. 

How data caching produces a negative impact on load testing?

- This is so because the data caching has got some pitfalls which come in our observation only when there are potential situations when there is a possibility of data expiry and software system or application using inconsistent data. 

- Using caching technique is quite simple but any fault can cause an impact on load testing.

- Load testing involves putting demands on the software system or application in order measure its response. 

- The outcomes of the load testing helps in measuring the difference between the responses of the software system or application under normal as well as peak load conditions. 

- Load testing is usually used as a means to have a measure of the maximum capacity at which the software system or application can operate easily. 

- Data caching initiates quick response from the software system or application for obtaining cookies etc. 

- Though data caching responds faster than the usual memory transactions, it has a negative impact on the result of the load testing i.e. you will not get the original results rather the results you will get will be the altered ones. 

What you will get to see is the wrong performance of the software system or application. 

What is the purpose of caching?

- Caching is done with the purpose of storing certain data so that that data in the subsequent stages can be served faster. 

- Data caching affects load testing results in a way until and unless the cache is cleared up by the testing tool after every iteration of the virtual user, an artificial faster page load time is started to be given by the caching mechanism. 

- Such artificial timings will alter your load testing results and invalidate them. - In caching, all the recently visited web pages are stored. 

- When we carry out load testing, our aim is always to check the software system or application under load. 

- So if by chance the caching option is left enabled, what will happen is that the software system or application will try retrieving the data from the data that is locally saved giving false measure of the performance determination. 

- So, the caching option should always be disabled while you carry out load testing. 

What are virtual users? For what purpose are virtual users created?

For the software developers it is quite frustrating to see their software systems and applications crashing soon after installing them. 

What impression such a failure of the software system or application will have on the user or the customer!

It is obvious that the customers and the users may think that the software product has not been through sufficient testing before the software product was released to them. 

It has become a standard in the world of software engineering that any organization developing a software system or application must follow a defined standard procedure for testing that software product in order to ensure its reliability as well as quality before it is shipped to the users or customers. This whole testing process is of the quality assurance. 

For every software product there might be a 100 ways in which it may be used by the user. Therefore, the software system or application must be checked in all these possible ways for the verification of whether or not the software product is working fine.

There are a number ways using which a software testing process can be made more effective then it is actually. 

- One of such ways is use of automated testing tool in which suites of tests as well as specific tests can be set up and can be run by the computer. 

- Number of hours of drudgery are reduced by a huge margin as well as time and money. 

- The saved energy and time can be re-focused upon the tasks that call for more human interaction. 

- This whole process makes the software product very much reliable.

- It is always a good idea to verify the quality of the software artifact before it is shipped out. 

One of the automated testing tools is the virtual user than can help in this regard. In this article we talk about virtual user and with what purpose this tool has been created. 

What is a Virtual User and Purpose of Virtual User?

- Virtual user in abbreviated form is known as VU and is a kind of tool that helps a computer in emulating a human user i.e., it helps in performing actions like typing of words, commands and clicking of mouse and so on. 

- The computer on which the virtual user is installed actually acts as a host and takes the control of the other under itself just as a human tester would do. 

- One of the targeted computer systems is asked to act as an agent and receive instructions from the host computer. 

- The environment of a virtual user is constituted by an application whose work is to compile and run the scripts. 

- The scripts of the virtual user cannot be edited in common editors rather it has to be edited in editors like MPW or BBEDIT. 

- Through the virtual user, all the computers are linked over a network. 

- The minimum requirements of the virtual user are:

1. Virtual user software package and
2. 2 systems one as host and the other one as target.

- Today many firms have launched their virtual user software packages. 
- Though the virtual user sounds like it’s a very good automating tool but it has got many drawbacks :

• It cannot tell you when something looks right on the test screen or it cannot tell you how a particular icon looks or what position it is at. 
• The biggest draw back is that the virtual user has got no intelligence of its own and if by chance a crash occurs in the machine, virtual user will keep trying to run the script regardless of the crash.