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WAP Advantages and Disadvantages

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The following are the advantages of WAP:
● Implementation near to the Internet model;
● Most modern mobile telephone devices support WAP;
● Real-time send/receive data;
● Multiplatform functionality (little change is needed to run on any web site since XML is used);
● No hardware obsolescence.

The following are some of the advantages of using WAP CSS on mobile Internet sites:
● Because of WAP 2.0 (XHTML MP/WAP CSS), web programming and WAP programming converge. Learning WAP programming does not require much effort if you already know how to program the web. Web developers can continue to use their familiar web authoring tools and PC web browsers for building mobile Internet sites. This is one major advantage of XHTML MP/WAP CSS over WML.

● You can have greater control on the appearance of WAP pages with WAP CSS than with WML. For example, you can specify the colors, fonts, background, borders, margins, and padding of various elements with WAP CSS.

● If you apply a single CSS to the whole mobile Internet site, a mobile device will download the CSS only once the fi rst time the mobile Internet site is visited. The CSS will then be stored in the cache and it can be accessed later without connecting to the server.

● The file sizes of XHTML MP documents can become smaller if the layout and formatting information is moved to an external WAP CSS style sheet. A small fi le
size has the advantage of a shorter download time.

● Using WAP CSS has the advantage that the content and presentation can be separated. This means you can:
1. Match the layout and style of the same content to the characteristics of different wireless devices easily.
2. Match the layout and style of the same content for different user agents easily.
3. Minimize the effort to maintain a WAP site. When new mobile phone models come onto the market, you can write new WAP CSS style sheets to optimize the layout of the WAP site on these new mobile phones. The content files do not need to be modifed.
4. Apply a single WAP CSS style sheet to multiple WAP pages. Later if you want to change the look and feel of the whole WAP site, just modify the WAP CSS.
5. Reuse the style code in multiple projects.
6. Remotely divide work — someone can focus on look and feel WAP, whereas others can concentrate on contents.

Some of the disadvantages of the WAP are the following:
● Low speeds, security, and very small user interface;
● Not very familiar to the users;
● Business model is expensive;
● Forms are hard to design;
● Third party is included.

Some of the disadvantages of using WAP CSS style sheets on mobile Internet sites are:
● Different WAP browsers have varied levels of support for WAP CSS. One property supported on one WAP browser may not be available on another WAP browser.

● An external WAP CSS style sheet can increase the time required for a page to be
completely loaded the fi rst time the WAP site is visited because of the following
reasons:
1. The external WAP CSS style sheet does not exist in the cache of the mobile phone at the first visit, which means the mobile phone has to download it from the server.
2. An XHTML MP document and its external WAP CSS style sheet have to be downloaded in separate requests.
3. If you make use of a single WAP CSS file to specify all the presentation
information about the mobile Internet site, the fi le size of the WAP CSS file can be quite large.
4. The WAP browser needs to parse the CSS in addition to the XHTML MP document.

Source of Information : Elsevier Wireless Networking Complete

Windows Performance Monitor

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The Performance Monitor in Windows Server 2008 R2, has been modified since Windows Server 2008 as it no longer includes the Reliability Monitor snapin. The Performance Monitor is composed of three main components: monitoring tools such as Performance Monitor, Data Collector Sets, and a reporting component. The Performance Monitor can be launched from within the Windows Server 2008 R2 Server Manager or from the Start, All Programs, Administrative Tools menu.

Using Performance Monitor, administrators can identify bottlenecks and pinpoint resource issues with applications, processes, or hardware. Monitoring these items can help identify and resolve issues, plan for capacity changes, and help establish baselines that can be used for analysis in the future. Upon launching the Performance Monitor, a summary of system performance is displayed, showing current memory, disk, processor, and network loads.


Performance Monitor
Many IT professionals rely on the Performance Monitor because it is bundled with the operating system, and it allows you to capture and monitor every measurable system object within Windows Server 2008 R2. Using the tool involves little effort to become familiar with it. You can find and start the Performance Monitor from within the Performance Monitor program under Monitoring Tools in the console view. The Performance Monitor, is by far the best utility provided in the operating system for capacity-analysis purposes. With this utility, you can analyze data from virtually all aspects of the system both in real time and historically. This data analysis can be viewed through charts, reports, and logs. The log format can be stored for use later so that you can scrutinize data from succinct periods of time.


Data Collector Sets
As mentioned previously, Data Collector Sets are a collective grouping of items to be monitored. You can use one of the predefined sets or create your own to group together
items that you want to monitor. Data Collector Sets are useful for several reasons. First, data collectors can be a common theme or a mix of items. For example, you could have
one Data Collector Set that monitors only memory or a Data Collector Set that contains a myriad of items such as memory, disk usage, processor time, and more. Data Collector Sets can also be scheduled to run when needed.


Reports
As previously discussed, the Performance Monitor includes an updated reporting mechanism and several template performance and diagnostic reports for use. In addition, reports can also be created manually or generated from Data Collector Sets. Three system reports are included for diagnosing and assessing system performance: LAN Diagnostics, System Diagnostics, and System Performance. The following steps outline the process to view a System Diagnostics report.

To create and view reports in Performance Monitor, do the following:
1. Expand Data Collector Sets and System in the console tree of Performance Monitor.

2. Right-click on either the System Diagnostics or System Performance sets and select Start. Windows will begin collecting data for the report.

3. When you have collected enough data, right-click the collection set again, and select Stop.

4. Expand Reports, System and click the collection set you chose earlier. Double-click the report listed under that performance set.

5. The report will be compiled and displayed.

Source of Information : Sams - Windows Server 2008 R2 Unleashed

What’s New in Network Monitor 3.3

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Network Monitor 3.3 is available in ia64, x64, and x86 versions and can run on Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows 7, Windows Vista, and Windows XP systems.

Network Monitor 3.3 expands on the capabilities of the previous versions of Network Monitor by including several more features and fixes for issues that were discovered in the 3.x versions. Network Monitor 3.3 is very flexible and can even stop a capture based on an event log entry in Event Viewer.

The previous versions of Network Monitor included the following:
. An optimized interface that included network conversations and an expandable tree view of frames for the conversation(s)

. A real-time display and updating of captures

. The ability to capture traffic on multiple network cards simultaneously

. The ability to run multiple capture sessions simultaneously

. A script-based protocol parser language

. Support for Windows Server 2008, Windows Vista, Windows XP, and Windows Server 2003 on 32- or 64-bit platforms

. The ability to capture wireless traffic, scan one or all wireless channels supported by the network card, and view signal strength and transfer speed of the connection

. The ability to trace traffic inside of a Windows Vista virtual private network (VPN) tunnel by capturing remote access server (RAS) traffic

. The ability to right-click in the Frame Summary pane and click Add to Filter

. Support for the Windows Update service by periodically checking for updates to the Network Monitor program

. A redesigned filter toolbar

. A redesigned engine for supporting more protocol schemes

. New public parsers like ip1394, ipcp, PPPoE, and more


Some of the new features in Network Monitor 3.3 include the following:

. Support for Windows Server 2008 R2, Hyper-V, and Windows 7

. The ability to capture WWAN and tunnel traffic on Window 7 computers

. Support for both IPv4 and IPV6

Source of Information : Sams - Windows Server 2008 R2 Unleashed

Task Manager

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The Windows Server 2008 R2 Task Manager is similar to its Windows Server 2008 and Windows Server 2003 predecessors in that it offers multifaceted functionality. You can view and monitor processor, memory, application, network, services, user, and process related information in real time for a given system. This utility is a well-known favorite among IT personnel and is great for getting a quick view of key system health indicators with the lowest performance overhead.

To begin using Task Manager, use any of the following methods:

. Press Ctrl+Shift+Esc.

. Right-click on the taskbar and select Start Task Manager.

. Press Ctrl+Alt+Delete and then click Start Task Manager.


The Task Manager window contains the following six tabs:
. Applications—This tab lists the applications that are currently running. You can start and end applications from this tab.

. Processes—On this tab, you can find performance metric information of the processes currently running on the system. Sorting the processes by CPU or memory usage will reveal which processes are consuming the most system resources.

. Services—A recent addition to Windows is the Services tab in Task Manager. Administrators can now see what services are running without having to load Computer Management or the Services Management Console (services.msc) separately.

. Performance—This tab can be a graphical or tabular representation of key system parameters such as kernel usage, paging, CPU cycles, and more—in real time.

. Networking—This tab displays the network traffic coming to and from the machine. The displayed network usage metric is a percentage of total available network capacity for a particular adapter.

. Users—This tab displays users who are currently logged on to the system.

In addition to the Task Manager tabs, the Task Manager is, by default, configured with a status bar at the bottom of the window. This status bar, displays the number of running processes, CPU utilization percentage, and the amount of memory currently being used.

As you can see, Task Manager presents a variety of valuable real-time performance information. This tool is particularly useful for determining what processes or applications are problematic and gives you an overall picture of system health with quick access to terminate applications and processes, or identify potential bottlenecks.

There are limitations, however, which prevent it from becoming a useful tool for long term or historical analysis. For example, Task Manager can’t store collected performance information for future analysis and viewing; it is capable of monitoring only certain aspects of the system’s health, and the information that is displayed pertains only to the local machine. For these reasons alone, Task Manager doesn’t make a prime candidate for capacity planning.

Source of Information : Sams - Windows Server 2008 R2 Unleashed

Establishing Policy and Metric Baselines

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As mentioned earlier, it is recommended that you first begin defining policies and procedures regarding service levels and objectives. Because each environment varies in design, you can’t create cookie-cutter policies—you need to tailor them to your particular business practices and to the environment. In addition, you should strive to set policies that set user expectations and, more important, help winnow out empirical data.

Essentially, policies and procedures define how the system is supposed to be used—establishing guidelines to help users understand that the system can’t be used in any way they see fit. Many benefits are derived from these policies and procedures. For example, in an environment where policies and procedures are working successfully and where network performance becomes sluggish, it would be safe to assume that groups of people weren’t playing a multiuser network game, that several individuals weren’t sending enormous email attachments to everyone in the Global Address List, or that a rogue web or FTP server wasn’t placed on the network.

The network environment is shaped by the business more so than the IT department. Therefore, it’s equally important to gain an understanding of users’ expectations and requirements through interviews, questionnaires, surveys, and more. Some examples of policies and procedures that you can implement in your environment pertaining to end users could be the following:

. Email message size, including attachments can’t exceed 10MB.

. SQL Server databases settings will be enforced with Policy Based Management.

. Beta software, freeware, and shareware can be installed only on test equipment (that is, not on client machines or servers in the production environment).

. Specify what software is allowed to run on a user’s PC through centrally managed but flexible group policies.

. All computing resources are for business use only (in other words, no gaming or personal use of computers is allowed).

. Only business-related and approved applications will be supported and allowed on the network.

. All home directories will be limited in size (for example, 500MB) per user.

. Users must either fill out the technical support Outlook form or request assistance through the advertised help desk phone number.

Policies and procedures, however, aren’t just for end users. They can also be established and applied to IT personnel. In this scenario, policies and procedures can serve as guidelines for technical issues, rules of engagement, or an internal set of rules to abide by. The following list provides some examples of policies and procedures that might be applied to the IT department:

. System backups must include System State data and should be completed by 5:00 a.m. each workday, and restores should be tested frequently for accuracy and disaster preparedness.

. Routine system maintenance should be performed only outside of normal business hours, for example, weekdays between 8:00 p.m. and 12:00 a.m. or on weekends.

. Basic technical support requests should be attended to within two business days.

. Priority technical support requests should be attended to within four hours of the request.

. Any planned downtime for servers should follow a change-control process and must be approved by the IT director at least one week in advance with a five-day lead time provided to those impacted by the change.

Source of Information : Sams - Windows Server 2008 R2 Unleashed

The Benefits of Capacity Analysis and Performance Optimization

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The benefits of capacity analysis and performance optimization are almost inconceivable. Capacity analysis helps define and gauge overall system health by establishing baseline performance values, and then the analysis provides valuable insight into where the system is heading. Continuous performance monitoring and optimization will ensure systems are stable and perform well, reducing support calls from end users, which, in turn, reduces costs to the organization and helps employees be more productive. It can be used to uncover both current and potential bottlenecks and can also reveal how changing management activities can affect performance today and tomorrow.

Another benefit of capacity analysis is that it can be applied to small environments and scale well into enterprise-level systems. The level of effort needed to initially drive the capacity-analysis processes will vary depending on the size of your environment, geography, and political divisions. With a little up-front effort, you’ll save time, expense, and gain a wealth of knowledge and control over the network environment.

Source of Information : Sams - Windows Server 2008 R2 Unleashed

Defining Capacity Analysis

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The majority of capacity analysis is working to minimize unknown or immeasurable variables, such as the number of gigabytes or terabytes of storage the system will need in the next few months or years, to adequately size a system. The high number of unknown variables is largely because network environments, business policy, and people are constantly changing. As a result, capacity analysis is an art as much as it involves experience and insight.

If you’ve ever found yourself having to specify configuration requirements for a new server or having to estimate whether your configuration will have enough power to sustain various workloads now and in the foreseeable future, proper capacity analysis can help in the design and configuration. These capacity-analysis processes help weed out the unknowns and assist you while making decisions as accurately as possible. They do so by giving you a greater understanding of your Windows Server 2008 R2 environment. This knowledge and understanding can then be used to reduce time and costs associated with supporting and designing an infrastructure. The result is that you gain more control over the environment, reduce maintenance and support costs, minimize firefighting, and make more efficient use of your time.

Business depends on network systems for a variety of different operations, such as performing transactions or providing security, so that the business functions as efficiently as possible. Systems that are underutilized are probably wasting money and are of little value. On the other hand, systems that are overworked or can’t handle workloads prevent the business from completing tasks or transactions in a timely manner, might cause a loss of opportunity, or keep the users from being productive. Either way, these systems are typically not much benefit to operating a business. To keep network systems well tuned for the given workloads, capacity analysis seeks a balance between the resources available and the workload required of the resources. The balance provides just the right amount of computing power for given and anticipated workloads.

This concept of balancing resources extends beyond the technical details of server configuration to include issues such as gauging the number of administrators that might be needed to maintain various systems in your environment. Many of these questions relate to capacity analysis, and the answers aren’t readily known because they can’t be predicted with complete accuracy.

To lessen the burden and dispel some of the mysteries of estimating resource requirements, capacity analysis provides the processes to guide you. These processes include vendor guidelines, industry benchmarks, analysis of present system resource utilization, and more. Through these processes, you’ll gain as much understanding as possible of the network environment and step away from the compartmentalized or limited understanding of the systems. In turn, you’ll also gain more control over the systems and increase your chances of successfully maintaining the reliability, serviceability, and availability of your system.

There is no set or formal way to start your capacity-analysis processes. However, a proven and effective means to begin to proactively manage your system is to first establish system wide policies and procedures. Policies and procedures, discussed shortly, help shape service levels and users’ expectations. After these policies and procedures are classified and defined, you can more easily start characterizing system workloads, which will help gauge acceptable baseline performance values.

Source of Information : Sams - Windows Server 2008 R2 Unleashed

The WAP Programming Model

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Before presenting the WAP programming model, we briefl y discuss the WWW model that is the basis for the WAP model.


The WWW Model
The Internet WWW architecture provides a fl exible and powerful programming model. Applications and content are presented in standard data formats, and are browsed by
applications known as web browsers. The web browser is a network application, i.e., it sends requests for named data objects to a network server and the network server responds with encoded data using the standard formats.

The WWW standards specify several mechanisms necessary to build a general-purpose
application environment which includes:

● Standard naming model. All servers and content on the WWW are named with an Internet-standard Uniform Resource Locator ( URL ).

● Content typing. All content on the WWW is given a specific type, thereby allowing web browsers to correctly process the content based on its type.

● Standard content formats. All web browsers support a set of standard content formats. These include (HTML), JavaScript scripting language (ECMAScript, JavaScript), and a large number of other formats.

● Standard protocols. Standard networking protocols allow any web browser to communicate with any web server. The most commonly used protocol on the WWW
is the HTTP. This infrastructure allows users to easily reach a large number of thirdparty
applications and content services. It also allows application developers to easily create applications and content services for a large community of clients.

The WWW protocols defi ne three classes of servers:

1. Origin server: The server on which a given resource (content) resides or is to be created.

2. Proxy: An intermediary program that acts as both a server and a client for the purpose of making requests on behalf of other clients. The proxy typically resides between clients and servers that have no means of direct communication (e.g., across a firewall). Requests are ither serviced by a proxy program or passed on with possible translation to other servers. A proxy must implement both the client and the server requirements of WWW specifications.

3. Gateway: A server which acts as an intermediary for some other server. Unlike a proxy, a gateway receives requests as if it were the origin server for the requested resource. The requesting client may not be aware that it is communicating with a gateway.


The WAP Model
The WAP programming model is similar to the WWW programming model. This provides several benefits to the application developer community, including a familiar programming model, a proven architecture, and the ability to leverage existing tools (e.g.,
web servers, XML tools, etc.). Optimization and extensions have been made in order to match the characteristics of the wireless environment. Wherever possible, existing standards have been adopted or have been used as the starting point for the WAP technology.

WAP content and applications are specified in a set of well-known content formats based on WWW content formats. Content is transported using a set of standard communication
protocols based on WWW communication protocols. A microbrowser in the wireless terminal coordinates the user interface and is analogous to a standard web browser. WAP defines a set of standard components that enable communication between mobile terminals and network servers, including:

● Standard naming model : WWW-standard URLs are used to identify WAP content on origin servers. WWW-standard URLs are used to identify local resources in a device (e.g., call control functions).

● Content typing : All WAP content is given a specifi c type consistent with WWW typing. This allows WAP user agents to correctly process the content based on its type.

● Standard content formats : WAP content formats are based on WWW technology
and include display markup, calendar information, electronic business card objects,
images, and scripting language.

● Standard protocols : WAP communication protocols enable the communication of
browser requests from the mobile terminal to the network web server. The WAP
content types and protocols have been optimized for mass market, hand-held wireless
devices. WAP utilizes proxy technology to connect between the wireless domain and
the WWW.

The WAP proxy typically comprises the following functionality:
● Protocol gateway : The protocol gateway translates requests from the WAP protocol stack to the WWW protocol stack (HTTP and TCP/IP).

● Content encoders and decoders : The content encoders translate WAP content into compact encoded formats to reduce the size of data over the network. This infrastructure ensures that mobile terminal users can browse a wide variety of WAP content and applications, and that the application author is able to build content services and applications that run on a large base of mobile devices. The WAP proxy allows content and applications to be hosted on standard WWW servers and to be developed using proven WWW technologies such as cell global identity (CGI) scripting. While the nominal use of WAP includes a web server, WAP proxy, and WAP client, WAP architecture can easily support other confi gurations. It is possible to create an origin server that includes WAP proxy functionality. Such a server might be used to facilitate end-to-end security solutions, or applications that require better access control or a guarantee of responsiveness.

Source of Information : Elsevier Wireless Networking Complete 2010

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