What are the services provided to upper layers by transport layer?

In the field of computer networking, the purpose of the 4^th layer or the transport layer is to provide services for the end to end communication for the various operating applications. The services are provided within an architectural framework that consists of protocols and the components and is layered. It also offers convenient services such as the following:

Ø  Connection – oriented data stream support

Ø  Reliability

Ø  Flow control

Ø  Multiplexing and so on.

- Both the OSI (open systems interconnection) and TCP/ IP model include the transport layer. 

- The foundation of the internet is based up on the TCP/ IP model whereas for the general networking, the OSI model is followed. 

- However, the transport layer is defined differently in both of these models. Here we shall discuss about the transport layer in the TCP model since it is used for keeping the API (application programming interface) convenient to the internet hosts. 

- This is in contrast with the definition of the transport layer in the OSI model. 

- TCP (transmission control protocol) is the most widely used transport protocol and so the internet protocol suite has been named after it i.e., the TCP/ IP. 

- It is a connection-oriented transmission protocol and so it is quite complex. 

- This is also because it incorporates reliable data stream and transmission services in to its state-ful design. 

- Not only TCP there are other protocols in the same category such as the SCTP (stream control transmission protocol) and DCCP (datagram congestion control protocol).

Now let us see what all services are provided by the transport layer to its upper layers:

ØConnection-oriented communication: It is quite easy for the application for interpreting the connection as a data stream instead of having to cope up with the connectionless models that underlie it. For example, internet protocol (IP) and the UDP’s datagram protocol.

Ø Byte orientation: Processing the data stream is quite easy when compared with using the communication system format for processing the messages. Because of such simplification, it becomes possible for the applications to work up on message formats that underlie.

Ø  Same order delivery: Usually, it is not guaranteed by the transport layer that the data packets will be received in the same order in which they were sent. But this is one of the desired features of the transport layer. Segment numbering is used for incorporating this feature. The data packets are thus passed on to the receiver in order. Head of line blocking is a consequence of implementing this.

Ø  Reliability: During the transportation some data packets might be lost because of errors and problems such as network congestion. By using error detection mechanism such as CRC (cyclic redundancy check), the data might be checked by the transport protocol for any corruption and for the verification whether the correct reception of the data by either sending a NACK or an ACK signal to the sending host. Some schemes such as the ARR (automatic repeat request) are sometimes used for the retransmission of the corrupted or the lost data.

Ø  Flow control: The rate with which the data is transmitted between two nodes is managed for preventing a sending host with a fast speed from the transmission of data more than what the receiver’s data buffer can take at a time. Otherwise it might cause a buffer overrun.

Ø  Congestion avoidance: Traffic entry in to the network can be controlled by means of congestion control by avoiding congestive collapse. The network might be kept in a state of congestive collapse by automatic repeat requests. 

What is Portability Testing?

- Portability Testing is the testing of a software/component/application to determine the ease with which it can be moved from one machine platform to another. 

- In other words, it’s a process to verify the extent to which that software implementation will be processed the same way by different processors as the one it was developed on.  

- It can also be understood as amount of work done or efforts made in order to move software from one environment to another without making any changes or modifications to the source code but in real world this is seldom possible.

- For example, moving a computer application from Windows XP environment to Windows 7 environment, thereby measuring the efforts and time required to make the move and hence determining whether it is re usable with ease or not.

- Portability testing is also considered to be one of the sub parts of System testing as this covers the complete testing of software and also it’s re-usability over different computer environments that include different Operating systems, web browsers.

What needs to be done before Portability testing is performed (pre requisites/pre conditions)? 

1.   Keep in mind portability requirements before designing and coding of software.

2.   Unit and Integration Testing must have been performed.

3.   Test environment has been set up.

Objectives of Portability Testing

1. To validate the system partially i.e. to determine if the system under consideration fulfills the portability requirements and can be ported to environments with different :-

a). RAM and disk space

b). Processor and Processor speed

c). Screen resolution

d). Operating system and its version in use.

e). Browser and its version in use.

To ensure that the look and feel of the web pages is similar and functional in the various browser types and their versions.

2.   To identify the causes of failures regarding the portability requirements, this in turn helps in identifying the flaws that were not found during unit and integration testing.

3.   The failures must be reported to the development teams so that the associated flaws can be fixed.

4.   To determine the potential or extent to which the software is ready for launch.

5.   Help in providing project status metrics (e.g., percentage of use case paths that were successfully tested).

6.   To provide input to the defect trend analysis effort.

What is the difference between a passive star and an active repeater in fiber optic network?

There are two important components of a fiber optic network namely passive star coupler and active repeaters. 

Passive Star in Fiber Optic Network

- Passive star couplers are single mode fiber optic couplers with reflective properties.  

- These couplers are used for optical local area networking at very high speeds. 

- These couplers are made from very simple components such as mirrors and 3 db couplers. 

- Besides this, these star couplers save a lot of optical fiber when compared to its trans-missive counterpart. 

- They are free of any multi-paths so as to avoid any interference. 

- A fiber optic network may consist of any number of passive star couplers and each of them is capable of connecting a number of users. 

- The input and output from every passive star coupler is given to the output and input of an active coupler. 

- The round trip transmission tile is stored by the active star coupler. 

- When it receives a signal from a passive star coupler, it stops the output to that coupler for the duration of the signal.

- It also inhibits the incoming data from all the other passive star couplers for the round trip transmission delay plus signal duration. 

- The purpose of a star coupler is to take one input signal and then splitting it in to a number of output signals. 

- In telecommunications industry and fiber optics communication, this coupler is used in network applications being a passive optical device. 

- If an input signal is introduced to one of the input ports, it is distributed to all of the output ports of the coupler. 

- As per the construction of the passive star coupler, the number of ports it will have is given by the power of 2. 

- For example, in a two port coupler or in a directional coupler or splitter, there are 2 input ports and 2 output ports.

- In a four port coupler, there are 4 i/p ports and 4 o/p ports and so on. 

- The digital equipment corporation also sold a device by the name of star coupler which was used for interconnecting the links and computers through coaxial cable instead of using optical fibers. 

Active Repeater in Fiber Optic Network 

- Active repeater is an important telecommunications device used for re transmitting the signal it receives to a higher level and with higher basically to the other side of an obstacle so that long distances can be covered. 

- Repeater is an electro-mechanical device that helps in regenerating the telegraphy signals. 

- It may be defined as an analog device for amplifying the input signal, reshaping it, re-timing it for re-transmission. 

- A re-generator is a repeater that can perform the re-timing operation. 

- Repeaters just tend to amplify the physical signal without interpreting the data transmitted by the signal. 

- The 1^st layer i.e., the physical layer is where the repeaters operate. 

- Repeaters are employed for boosting the signals in optical fiber lines as well as in twisted pair and coaxial cables. 

- When a signal travels through a channel, it gets attenuated with the distance and time because of the energy loss (dielectric losses, conductor resistance etc.). 

- When light travels in optical fibers, it scattered and absorbed and hence is attenuated. 

- Therefore, in long fiber lines, repeaters are installed at proper intervals for regenerating and strengthening the signal. 

Repeater in optical communication performs the following functions:

Ø  Takes the input signal

Ø  Converts it in to electrical signal

Ø  Regenerates it.

Ø  Converts it in to optical signal

Ø  Re-transmits it

- These repeaters are usually employed in submarine as well as transcontinental communication cables as the loss is unacceptable in these cases.  

Explain the structure of the operating systems.

We all are addicted to using computers but we all never really bother to known what is actually there inside it i.e., who is operating the whole system. Then something inevitable occurs. Your computer system crashes and the machine is not able to boot. Then you call a software engineer and he tells you that the operating system of the computer has to be reloaded. You are of course familiar with the term operating system but you know what it is exactly. 

About Operating System

- Operating system is the software that actually gives life to the machine. 

- Basic intelligence is the requirement of every computer system to start with. 

- Unlike we humans, computers do not have any inborn intelligence. 

- This basic intelligence is required because this is what the system will use to provide essential services for running the programs such as providing access to various peripherals, using the processor and allocation of memory and so on. 

- One type of service is also provided by the computer system for the users. 

- As a user, you may require to create, copy or delete files. 

- This is the system that manages the hardware of the computer system. 

- It also sets up a proper environment in which the programs can be executed. 

- It is actually an interface between the software and the hardware of the system.

- On booting of the computer, the operating system is loaded in to the main memory. 

- This OS remains active as long as the system is running. 

Structure of Operating Systems

- There are several components of the operating system about which we shall discuss in this article.

- These components make up the structure of the operating system.

1. Communications: 

- Information and data might be exchanged by the processes within the same computer or different computers via a network. 

- This information might be shared via memory if in the same computer system or via message passing if through some computer network. 

- In message passing, the messages are moved by the operating system.

2. Error detection: 

- The operating system has to be alert about all the possible errors that might occur. 

- These errors may occur anywhere ranging from CPU to memory hardware devices in the peripheral devices in the user application. 

- For all types of error, proper action must be taken by the operating system for ensuring that correct and consistent computing takes place. 

- The users and the abilities of the programmers are enhanced greatly by the debugging facilities.

3. Resource allocation: 

- Resources have to be allocated to all of the processes running. 

- A number of resources such as the main memory, file storage, CPU cycles etc have some special allocation code while other resources such as I/O devices may have request and release codes.

4. Accounting: 

- This component is responsible for keeping the track of the computer resources being used and released.

5. Protection and Security: 

- The owners of data and information might want it to be protected and secured against theft and accidental modification.

- Above all, there should be no interference of the processes with working of each other. 

- The protection aspect involves controlling the access to all the resources of the system. 

- Security involves ensuring safety concerning user authentication in order to prevent devices from invalid attempts.

6. Command line interface or CLI: 

- This is the command interpreter that allows for the direct entry of the command. 

- This is either implemented by systems program or by the kernel.

- There are a number of shells also for multiple implementations.

7. Graphical User Interface: 

This is the interface via which the user is actually able to interact with the hardware of the system. 

What are different components of operating system? – Part 5

This article is continued from “What are different components of operating system? – Part 4”.

10. Networking: 

- Presently, many different types of protocols along with applications and hardware for using them are supported by most of the operating systems. 

- The computers running different operating systems can easily become a part of the network and participate in resource sharing activities such as sharing of printers, scanners and of course files. 

- They may connect to network either through wired connection or a wireless one. 

- Through this component, OS of one computer system can access the resources of another computer system at a remote location. 

- Almost anything can be shared including remote computer’s sound and graphics card. 

- There are network services that allow transparent access to a computer’s resources like SSH.

- Client/ server networking allows a system to connect to a server which offers various services to its clients.

- Numbered access points or ports are used for providing these services beyond the network address of the server. 

- Maximum one running program can be associated to each of the port number which will handle all the requests.

- A user program can then access the local hardware resources by making a request to the kernel of its operating system.

11. Security: 

- The security of a computer system depends on the proper working of the technologies involved in it. 

- A modern OS lets you access many resources both for the internal applications and external devices through the kernel. 

- The operating system must have the capability of deciding which requests are to be allowed and which are to be rejected. 

- There are some systems which decide this on the basis of some requester identity which they further classify as privileged or non–privileged. 

- For establishing the identity there has to be some form of authentication. 

- Mostly a username or ID is quoted along with a password. 

- Some other methods are bio-metric data or magnetic cards. 

- There are cases where no authentication is required for accessing resources. 

- Another concept under security is the authorization. 

- The services which can be accessed by the requester are tied to his/ her account or to group in which he/ she belongs. 

- Some auditing options are also offered by systems having a high security level. 

- With these the requests from various sources can be tracked. 

- Internal security is also essential from the programs that are currently executing. 

- It is maintained by raising interrupts to the kernel of the OS. 

- If direct access is provided to the programs for hardware, then security cannot be maintained.

12. User Interface: 

- For an operating system to be operated by a user, a user interface is required. 

- This interface is termed as the shell and is vital if the operating system is to work according to the user’s instructions. 

- The directory structure is observed by the user interface and then it sends requests for the services wanted by the OS from the input hardware devices. 

- It also sends requests to the operating system demanding for the status messages and prompts to be displayed on output hardware devices. 

- There are two most common forms of the user interface namely the GUI (graphical user interface) and the CLI (command line interface). 

- In the former, the environment is visual and in the latter case the commands have to be typed line by line. 

- Almost, all the modern operating systems come with a graphical user interface.

- In some operating systems such as Mac OS, the GUI is already integrated in to its kernel. 

- There are some operating systems that are modular in nature.  

What are different components of operating system? – Part 4

This article is continued from “What are different components of operating system? – Part 3”.

8. Disk access and file systems: 

- Through this component of the operating system, the users as well as the programs they use are able to sort and organize files on a computer system. 

- This is done through the use of folders or directories. 

- This is another central feature of the operating systems. 

- Data is stored by the computers on disks in the form of files which are then structured in some certain predefined ways so as to enable faster access, better use of available memory and higher reliability. 

- These specific ways of the storing the data on disk together constitute the file system. 

- This makes it possible to assign names and attributes to the files. 

- This in turn helps in maintaining the hierarchy of directories and folders in the directory tree. 

- Only one type of file system and one disk drive was supported by the old operating systems. 

- Those file systems had a limited capacity in terms of directory structures and file names that could be used and speed. 

- These limitations were actually the reflection of the operating system’s limitations making it difficult for it to support multiple file systems. 

- There are other simple operating systems that have a limited range of storage accessing options.

- On the other hand Unix and Linux like operating systems support the VFS technology or virtual file system. 

- Unix offers support for a wide range of storage devices irregardless of their file system or design. 

- This enables them to be accessed via a common API (application programming interface). 

- For programs this avoids the need of having knowledge about the devices which they may require to access.

- With virtual file system, the OS can provide access of unlimited devices to the programs having many file systems operating in them.

- This it does through the use of file system drivers and other device drivers. 

- A device driver lets you access a connected storage device such as flash drives. 

- Every drive has a specific language which is only understood by the device driver and it translates it in to a standard one used by the OS for accessing the drives.

- The contents of the drive can be accessed by the kernel only if the device driver is in place. 

- The purpose of the file system driver is to translate the commands used for accessing the file systems in to the standard set recognized by the operating system. 

- These file systems are then dealt by the programs based on their directories or folders and file names organized in hierarchy. 

- These files can be created, deleted or modified by the programs.

9. Device Drivers: 

- This specifically developed computer software enables the interaction with the hardware devices. 

- It creates an interface through which communication can be done with the device via communications sub system or bus i.e., the means through which the hardware is connected to the system. 

- This computer program depends up on the hardware but is also specific to the operating system.

- It enables an applications software package running under kernel in order to interact with the hardware device transparently.

- Further, it raises the requisite interrupt required for handling asynchronous time dependent interfacing needs of the hardware. 

- Abstraction is the key goal of the device drivers.

- Every hardware model is different and so the operating system cannot know about how each device will be controlled. 

- The way the devices should be controlled is now dictated by the operating systems as a solution to this problem. 

- Therefore, translating the function calls from the OS into calls specific to the device becomes the purpose of the device drivers. 

- Any device would function properly if a device driver suitable to it is available which will ensure the normal operation of the device from the viewpoint of the OS. 

Read the next post "What are different components of operating system? – Part 5"

What are different components of operating system? – Part 3

This article is continued from “What are different components of operating system? – Part 2”.

6.   Virtual memory: 

- This is that component of the operating system that lets it trick programs to use the memory that scattered all around the RAM and hard disk as one continuous memory location. 

- This chunk of memory is called the virtual memory.

- Using various means of virtual memory addressing such as segmentation and paging implies that it is up to the kernel for choosing the type of memory that might be used by the program at a given time. 

- This enables the use of same memory locations by the operating system for executing multiple tasks. 

- If a program makes an attempt for accessing memory that does not lie in the present range of memory that is accessible but has not been allocated, an interrupt is raised for the kernel in the same way as it would be done for the program if it would exceed its memory. 

- Such an interrupt is called as a page fault.

- When a page fault is detected by the kernel, the virtual memory range of the application is adjusted through which the access to memory is granted to it. 

- In this way, discretionary power is given to the kernel over the memory storage of a particular application. 

- The frequently accessed memory is stored temporarily on the hard disk or other types of media in today’s operating systems. 

- This is done to make some space for the other programs.

- This process is termed as swapping because a memory area is used by a number of programs and its contents can be exchanged or swapped with that of the other memory locations up on demand. 

- Virtual memory is a way of gaining a perception such that amount of RAM is larger than usual in the system.  

7. Multi – tasking: 

- Execution of multiple programs that are also independent on the same system is termed as multi–tasking. 

- It gives appearance that the tasks are being performed at the same time. 

- There are computers that are capable of running at the most two programs simultaneously through the principle of time sharing. 

- A share of computer time is used by each of the programs for their execution. 

- A piece of software known as the scheduler is contained in the operating system whose purpose is to determine how much time will be spent for the execution of every program, and in which order it would take place.

- It also determines how the control will be passed to the programs. 

- The kernel then passes the control to the process allowing the program to access the memory and the CPU. 

- Later on, through some mechanism the control is returned to the kernel so that CPU might be used by some other program. 

- This process of passing control between the application and the kernel is referred to as the context switch. 

- The concepts concerning the application preemption have been extended and used by the modern operating systems in order to maintain preemptive control over the internal run times. 

- The philosophy that governs the preemptive multi–tasking is to make sure that regular time of CPU is given to all the programs.

Read the next post "What are different components of operating system? – Part 4"

What are different components of operating system? – Part 2

All the components of an OS must exist in order so as to make the different parts of a system work together in cooperation. All the hardware needs of a software application are satisfied only through the operating system, be it as simple as mouse movement or as complex at Ethernet.

This article is continued from “Whatare different components of operating system? – Part 1”.

4. Modes: 

- A number of modes of operations are supported by today’s CPUs. 

- CPUs having the capability to support multiple modes at the least use the following two basic modes:

Ø  The supervisor mode: The kernel of the operating system uses this mode for accomplishing low level tasks i.e., the tasks that have no restricted access to the computer hardware. Few examples of such tasks are: communicating with devices such as the graphic cards and maintaining a control over the read, write and erase operations of the memory.

Ø  The protected mode: This mode is just the opposite of the previous one and so is use for everything else. Application software which runs under the protected mode can access the computer hardware only by going through the kernel which in turn controls the tasks only in supervisor mode.

- There are other types of modes similar to the above two, such as virtual modes that might be used by the CPUs for emulating old types of processors such as the following: 32 bit processor on a 64 bit processor or a 16 – bit one on a 32 bit one etc.

- The former one is the mode in which a computer runs automatically after start up. 

- The first programs that run include EFI or BIOS, OS and the boot loader. 

- These programs require unlimited access to the computer hardware because a protected environment can only be initialized outside of one. 

- The CPU is transferred to protected mode only when the control is passed to some other program by the operating system. 

- When a program is running under the protected mode, the number of CPU instructions to which it is granted access might be very limited. 

- If a user wishes to leave the protected mode, he / she can raise a interrupt that will pass the control again to the operating system. 

- This is how an operating system maintains an exclusive control over the issues concerning access to the memory and the hardware. 

- One or more CPU registers that consist of information that is prohibited to be accessed by the currently executing program are collectively termed as the ‘protected mode resources’. 

- If at all an attempt is made for altering this resource, the system switches to supervisor mode.

- Now it is the OS who deals with such illegal operations. It may kill the program.

5. Memory management: 

- Kernel of a multi–programming OS is held responsible for the management of the system memory that is currently under use by the programs. 

- Kernel ensures that the programs under execution do not interfere with the memory being used by the each other.

- Since time sharing principle is followed; each of the programs is given an independent access to the system memory. 

- Early operating systems used to have a cooperative memory management system. 

- It was assumed that all the programs used the memory manager of kernel voluntarily without exceeding the memory limit assigned to them. 

- However,this system of memory management is extinct now because there are bugs in programs that cause them to exceed the limits.

- Failure of a program might cause the memory to be overwritten by the other programs using it. 

- Memory being used by the other programs might be altered by some viruses or malicious code for some purpose which in turn may affect the working of the OS. 

- In such management, the misbehaving programs can crash the whole system. 

- Kernel limits the access to memory for various programs through various methods of memory protection such as paging and segmentation. 

Read the next post (What are different components of operating system? – Part 3)

What are different components of operating system? – Part 1

All the components of an OS must exist in order so as to make the different parts of a system work together in cooperation. All the hardware needs of a software application are satisfied only through the operating system, be it as simple as mouse movement or as complex at Ethernet.

1. Kernel: 

- This component of the OS is the medium through which application software can connect to the computer’s hardware system. 

- This component is aided by many device drivers and firmware. 

- With the help of these, it provides a very basic control level for all the hardware devices of a system.

- For programs, the memory access in RAM and ROM is managed by kernel only. 

- It is the authority of the kernel to decide which program should get what access and at what level. 

- The operating state of the CPU is set up the kernel itself all the time. 

- It prepares the data to be stored in long term non–volatile storage like in flash memory, tapes, and disks and so on.

2. Program execution or process: 

- The OS is actually an interface between the hardware and the application software.

- An interaction between the two can be established only if the application abides by the rules and procedures of the operating system as programmed in to it. 

- It is another purpose of the operating system to provide a set of services for simplifying the execution as well as development of the programs. 

- Whenever a program is to be executed, a process is created by the kernel of the operating system and then other required resources such as memory are assigned to it. 

- A priority is assigned to this process if it is a multi–tasking environment. 

- The binary code for the program is loaded in to the memory and the execution is initiated.

3. Interrupts: 

- This component is the central requirement of the operating systems. 

- This is so because the interrupts provide a way of interaction between the OS and its environment which is not only reliable but also effective. 

- The older operating systems worked with very small stacks and therefore watched for the various input sources requiring action for initiating some event (called polling).

- This strategy is not useful in today’s OS that use very large stacks. 

- Here, interrupt - based programming is fruitful. 

- The modern CPU have in – built direct support for these interrupts. 

- With the use of interrupts, a computer knows when to automatically save the contexts of the local registers or run some specific code in response to the occurring events. 

- Hardware interrupts are supported by very basic of the computers. 

- Interrupts let the programmer to specify what code is to be run when a certain even occurs. 

- When hardware receives an interrupt, it automatically suspends the current program being executed by it. 

- The status of the program is saved and the code associated with the interrupt is executed. 

- In modern operating systems, the kernel is responsible for handling the interrupts. 

- Either of the running program or the computer’s hardware might raise an interrupt. 

- When an interrupt is triggered by a hardware device, it is left to the OS’s kernel to decide what to do now through execution of some code. 

- The code that has to be run is decided based up on the interrupt’s priority. 

- The device driver is the software to which all the task of the processing hardware interrupts is assigned. 

- A device driver might be a part of the kernel, or some other program or both.

Read the next post (What are different components of operating system? – Part 2)

What are components of autonomic networking?

The concept of the autonomic systems has been derived from a biological entity called the autonomic nervous system (ANS). In human body this system is responsible for carrying out functions such as blood pressure and circulation, respiration and emotive response. 

In this article we discuss about the various components of the autonomic networking.

Components of Autonomic Networking

Autognostics: 

- This category of autonomic components includes capabilities such as that of awareness, self – discovery and self – analysis. 

- With all these capabilities, an autonomic system is capable of having a high – level view. 

- In other words, we can say that perceptual sub–systems are represented by it which serves the purpose of gathering, analyzing and reporting on the conditions and states of the system. 

- These components provide a basis to the system for responding and validating its decisions. 

- In simple words, autognostics provide self – knowledge. 

- This component if is rich, might provide various perceptual senses. 

-In autonomic systems, models of both the external and internal environments are embedded through which perceived threats and states can be assigned some relative value. 

- When it comes to autonomic networking, inputs from the following are taken for defining the state of the network:

a) Various network elements such as network interfaces and switches (inclusive of the current state and specification and configuration.

b) End – host

c)  Traffic flows

d) Logical diagrams

e) Design specifications

f)   Application performance data

- This component inter operates with the other components of the autonomic system.

Configuration management: 

- The responsibility for the interactions that take place among the interfaces and the elements.

- It consists of an accounting capability with which it is possible to track the configurations over the time under various circumstances. 

- Metaphorically, they act as the memory for the autonomic systems. 

- Provision and the remediation over a network can be applied through the configuration settings.

- In addition to these, two other things which can be applied are the selective performance and the implementation affecting access.

- This category only contains the actions that are taken by the human engineers. 

- There are a very few exceptional cases where the interface settings are configured manually using the automated scripts. 

- The dynamic population of the devices is maintained implicitly.

- This component must have the capability operating on all devices and to recover the old configuration settings. 

- There can be some situations where the states may become unrecoverable. 

- Therefore, the sub – system must be capable of assessing the consequence of the changes before they are issued.

Policy management: 

- This component is inclusive of the following:

a)   Policy specification

b)   Deployment

c)   Reasoning over the policies

d)   Update of policies

e)   Maintenance of the policies

f)    Enforcement

- The reasons for including this component are:

a)  Configuration management

b)  Definition of the roles and relationships

c)  Establishment of trust and reputation

d)  Description of business processes

e)  Definition of performance

f) Constraints on behavior issues such as privacy, resource access, collaboration and security.

- It represents a model of ideal behavior and environment representing effective interaction.

- For defining the constituents of a policy it is important to know what all is involved in its management.

Autodefense: 

- The mechanism presented by this component is both dynamic and adaptive in nature.

- This mechanism has been developed to keep the network infrastructure safe from the malicious attacks. 

- Further, it also prevents the illegal use of the infrastructure for attacking the various technological resources. 

- This component has the capability of striking a balance between the various performance objectives that have threat management actions. 

- This component can be compared to the immune system of the human body.

Security: 

The structure provided by the security component is responsible for defining and enforcing the relationships between the following:

a)   Roles

b)   Content

c)   resources