Computer technology: 02/14/08

IP SAN Performance - Overview

SAN benefits of improved storage utilization, high availability and data protection are well understood. Today there are two protocols available for building block-based SANs, FC and iSCSI. Both protocols use SCSI commands generated by the file systems of the servers. These SCSI commands are converted by the iSCSI or FC protocol so they can move thru a network to and from centralized disk storage systems where the commands are executed. In the case of FC the network equipment is specific to the protocol. In the case of iSCSI the network equipment type is anything that will handle IP packets, 1GB Ethernet is the most popular.
There are many IT professionals considering iSCSI based IP-SAN's as a means for centralizing storage for their application servers. As opposed to FC-SANs, IP-SANs have the benefit of being based on TCP/IP allowing businesses to use standard Ethernet equipment, NICs, tools and the knowledge base within their IT staff. But when data is being read and written across an IP-SAN and not to internal disk drives, users are concerned that network latencies will degrade server performance. Similar to an FC-SAN, when using an IP-SAN the server, the network and the storage system all play a part in application performance and client satisfaction. It's important to understand how to identify and eliminate latency bottlenecks to ensure superior application performance. In many cases, a properly designed IP-SAN can deliver better performance than internal disk drives.

Attaching a server to the IP-SAN - Server CPU induced Latency
Today's most popular operating systems support an iSCSI software initiator. The iSCSI initiator is software responsible for encapsulating the SCSI command into TCP/IP and placing it onto the network. iSCSI in itself is fairly low CPU intensive software and even during heavy loads uses very little of the CPU power. But TCP/IP can consume noticeable CPU resources. If you want to eliminate latency at the server layer and not dedicate much of the CPU/s for driving IP-SAN traffic, it is recommended to use an iSCSI TCP/IP TOE NIC. A TOE (TCP/IP Offload Engine) NIC is a special interface card specifically designed for interfacing a server to the IPSAN and will offload iSCSI as well and TCP/IP encapsulation from the server CPU/s. As a general rule an iSCSI TOE NIC (also called an iSCSI HBA) is recommended if your average CPU utilization before the use of iSCSI is higher than 50% during usual business hours, above 65% during peek use periods, or nearing 75% during backup or mirroring operations. Most iSCSI TOE NICs come with their own initiators so you'll want to check compatibility with your target operating systems before selecting a TOE. Network boot is also a feature supplied by some iSCSI TOE NICs.

Attaching a server to the IP-SAN - Saturating the Ethernet link to the LAN
"Server Fan-in" describes how many servers you can run thru a single GB Ethernet port within an IP-SAN before you start experiencing latency caused by excessive storage traffic. Average business servers do not generate from 50 to 200 IOP's (input/output operations) toward the storage drives. And in most cases do not generate more than 5 megabytes of storage traffic. As a general rule, assume a GB connection can support 80 megabytes of storage traffic and 10,000 IOPs. Using these figures you can attach up to 16 servers on a single GB connection assuming each server is not generating more than 5 megabytes per second of storage traffic.
It's important to note that iSCSI is encapsulated into TCP/IP and thus any network that supports TCP/IP can be used as part of an IP-SAN to move storage traffic including 10/100 connections, wireless, infrared LAN/MAN/WAN and even the internet. Naturally performance across these types of networks will vary greatly depending on connection speed but all have been tested and work. For new IP-SAN deployments, 1Gb is recommended.

As you can see, understanding your server statistics relative to storage IO, MBs and CPU usage is very important when determining what equipment to purchase and what size to make your IP-SAN solution. Most operating systems have performance monitoring tools and logs you can use to collect statistics on server CPU and storage usage. For example Windows performance monitoring can be done using "perfmon" and in Linux you can use "sysstat". This information in addition to your expansion plans will help you to determine the proper configuration and equipment needed to build an IP-SAN solution that will exceed the performance requirements of your business application servers and be able to scale into the future.

IP-SAN Network Speed - Selecting an Ethernet Switch
The main criteria for an Ethernet switch is that the switch is non-blocking. It can be either a layer 2 or layer 3 switch. Having a layer 3 switch is generally preferred for easier SAN management and monitoring. Today's IP networks are extremely fast and scalable. For example, it takes only a quarter second to send and receive a "ping command" from half way around the world. This is minuscule when compared to the time it takes to seek and read a 10K file from any disk drive. In all shared iSCSI/ IP storage models, the performance of the network is usually insignificant when compared to the performance of the disk storage system (Usually 5 to 10 times faster than the disk storage system).

IP-SAN Network Speed - Selecting an Intelligent IP-SAN Switch
Intelligent IP-SAN switches are designed to sustain very high levels of random read and write IOPs operations.
Intelligent storage switches manage the IP-SAN and eliminate the need for 3rd party software and agents.
Intelligent switches have high-speed internal architectures utilizing network processors, real-time operating systems and 25Gb backplanes. They provide necessary storage services like security, virtual disk creation, multi-pathing, failover and mirroring for high availability, protocol conversion to use basic SCSI or FC disk arrays, virtual disk resizing, backup and data replication. A single IP-SANs switch generally has many Ethernet ports and can sustain 300 megabytes per second or 600 megabytes per seconds when clustered of random read and write requests and over 60,000 IOPs. This delivers raw random read or write performance and complete storage services for well over 100 standard business application servers assuming all the servers do not simultaneously generate more than 5 megabytes per second and 600 IOPs. If needed, more servers can be attached assuming that all the servers not peek at exactly the same time. The transverse would also be true if you had high-end servers generating over 25 megabytes each and 3000 IOPs, the IP-SAN could reasonably only support 20 such servers. Like arrays, intelligent IP-SAN switches are available is difference sizes.

Selecting the Appropriate Centralized Disk Storage System
IP-SANs can utilize any type of storage system. This allows the IT professional to select the storage system/s that best fit the performance and reliability needs of the organization. Moreover you can select different classes of storage. For example you can use an attached FC array rated for 200 MBs and 20,000 IOPs for servers requiring high performance (10 to 20 megabytes per second / 2000 IOPs) and use a lower cost array with slower drives and interface rated for 40MBs and 3000 IOPs for applications requiring less performance (under 5 megabytes per second / 500 IOPs). Because the IP-SAN can use different grades of storage, it's easy to construct a SAN with primary, secondary and even tertiary storage.
In addition to selecting different classes of storage (different cache and drive types), IP-SANs can simultaneously read and write data to multiple independent storage systems. Unlike individual storage arrays that cannot address more than their own internal storage capacity without causing significant performance IP SAN Performance WP-013-02 Copyright SANRAD 4 degradation, IP-SANs can simultaneously read and write to multiple independent storage arrays. By spreading volumes across independent storage systems and being able to directly access those storage systems without having to pass thru another control layer, IP-SAN's can maintain line speed performance to the storage systems (up to 2GBs, 200MBs, 20,000 IOPs per storage array) regardless of the location of the data. Moreover, since the storage systems are independent of the intelligent storage switches, capacity can be increased with additional arrays without degrading performance or having to suspend application servers.
In selecting a storage system for any SAN it's important to understand that the array/s will be shared among all the servers. By the nature of a shared storage system, random read and write performance is significantly more important than sequential performance specifications. This is obvious since the storage solution is shared among many application servers, each using unique volumes and reading and writing data whenever and wherever required. In general, published MBs (megabyte per second) specifications for disk drives and arrays are for sequential large block writes (1028k). This provides the optimum performance and is usually what is published. But within a SAN random IO and use of smaller block sizes (1k to 16k) is common. It's very important to work with your storage and IP-SAN supplier to understand the performance of the array within a random access environment and how to configure the array or optimum performance.
For further reading please go to IPSAN Performance White Paper.

Is Software Hard?

Systems are logical, programming is physical."
- Bryce's Law

For something that is supposed to be "soft", software exhibits
some pretty "hard" characteristics. The original premise behind the
COBOL programming language was to devise a language that could
be easily ported to several computers. As we all know, this never
truly happened due to computer manufacturers who tweaked the language
to suit their particular needs. What ran on an IBM machine, for
example, didn't necessarily run the same on Honeywell, UNIVAC, or
the rest of the BUNCH. Consequently, software developers had to
maintain different versions of source code to suit the particular
needs of the various computer compilers. This plagued all third
generation languages until Sun introduced JAVA in the 1990's. The
JAVA premise that a programmer should "write once, run everywhere"
was the right idea and the language began to gain momentum, until
it ran into Microsoft who didn't want to turn the operating system
into an inconsequential afterthought. JAVA lives on, but not to
the extent it should have, and developers are back to managing
separate versions of source code.

The point is, software does in fact exhibit some very "hard"
characteristics as it is married to the host computer configuration
making it not very portable. As mentioned, this creates headaches
for those of us, particularly commercial software vendors, in
terms of maintaining consistency in the different versions of
our products.

What to do?

Back in the 1970's and 1980's we were faced with the dilemma of
managing a single product on over a dozen different platforms. We
quickly came to the realization we would go stark raving mad
managing multiple versions of source code and came to the conclusion
we had better come up with a solution pretty quick. Because of our
experience in converting software, we became well versed in the
nuances of the various compilers and devised a Repository (we
called it a "filter program" at the time) which maintained the rules
of the various compilers. We were also very disciplined in writing
code to specific standards and embedded certain switches in the
base source code. When we were ready to produce a new release of
our product, we would feed the base code into our "filter program"
which would then create the different versions of the source
code ready for compilation. This saved us an incredible amount
of time and brought consistency to all of the versions of the
product. In other words, our programming staff worked with only
one set of code (not multiple variations), the "filter program"
then analyzed it and created the necessary permeation for a targeted
platform. As compilers changed, we would update the "filter
program" accordingly.

We also learned to maintain print maps, screen panels, messages
and help text separate from the source code, which greatly
enhanced our ability to create a new version of the product to
suit a foreign language and culture; see "Creating Universal
Systems" at:

http://www.phmainstreet.com/mba/pride/isspus.htm

Let us take it a step further, for years we have touted
there are logical and physical dimensions to Information
Systems. Using the "PRIDE" Standard System Structure concept
in "PRIDE"-ISEM, we look upon Systems and Sub-Systems (business
processes) as logical constructs, and Procedures and Programs
as physical constructs. Further, data components such as inputs,
outputs, files, records and data elements can be specified
logically and implemented physically many different ways. Let
me give you an example; back in the 1980's one of our "PRIDE"
users (a large Fortune 500 electronic conglomerate) bought
into our logical/physical concept and decided to put it to the
test. Working from their corporate offices, they designed a
complete Payroll System which they wanted to implement as the
corporate standard across all of their divisions and
subsidiaries. They completed the system with a recommended
programming solution they wrote themselves (no packages were
used) which I believe was an IBM MVS solution using COBOL. However,
they recognized early on this implementation wouldn't work
across the board in the company. Consequently, they gave the
system specifications to all of their divisions who would then
program it themselves in-house. The project turned out to be
a major success and the company ended up with multiple
implementations of the same system under IBM MVS, VM,
Honeywell GCOS, UNIVAC Exec, HP MPE, DEC VAX/VMS, and
Prime; all working harmoniously together. Other "PRIDE" users
experienced similar successes, particularly in Japan.

All of this drives home the point that systems are logical in nature,
and that programming is physical. If systems are designed
properly, there is no reason they shouldn't behave identically
on whatever computer platform you come up with. Better yet, it
allows us to easily migrate our systems from one configuration
to another. Uniformity and consistency in execution; and portability
to boot. Imagine that.

Productivity and the Big Project Myth

Job advertisements in newspapers and on the internet asking for IT professionals usually tout large projects as the sole reason for wanting an IT professional in the first place. A programmer, system analyst or system tester must have had experience in large corporate projects and the larger the better.

Many businesses, in Australia at least, see IT departments as a liability and a necessary evil so as little money as necessary is thrown into IT infrastructure where other areas of a business, for example the Engineering Department or the Buyers Department, get inundated with large budgets. IT Departments have to justify their existence with staff time-sheets and charging internal clients for IT solutions.

Although grandiose back-slapping projects bring in the money and look good on a resume these projects do not necessarily improve the expediency with which a company does business. In fact large corporate systems can increase the workload where more data is required to be captured by the users, call centre staff and so on.

Throughout my consultancy career my main philosophy has been to improve the user's or developer's work environment by making their job easier. As well as large projects I have developed many small applications that took anywhere between 15 minutes to an hour to create but have saved employees anywhere between hours to months of hard tedious work. The accumulation of small time-saving applications can out-perform some of the larger projects when measuring productivity especially when used over and again exponentially increasing productivity within a company.

Those employees who benefit from many of these small applications are usually confined to the IT department itself where users have direct access to an IT professional who can put together a small custom application during their spare time. Those outside of the IT department though are usually left to their own devices and this is where end users and macro recordable office suites or keyboard capturing software comes into play.

What begins as simple macro instructions within an application built by an end user eventually become large complex and business critical applications held together with chewing gum and string. As news of the application spreads throughout the department more demands are made upon the hapless user who provided the solution and ergo their stress is increased as they maintain the original solution with all its additions whilst trying to cater for a stream of new requests. When a system grows to the point of being unmanageable the department can then justify the expense of a business case which the IT department will then accept, all too often though the business case specifies an upgrade of the original system, a band-aid solution as the ultimate solution, where a total rewrite is really the only solution.

There would be more control over such a situation if IT departments provided small applications for individuals and groups, and companies realised the benefits of incorporating the IT department more into its overall infrastructure instead of annexing it to the companies structure as if it were a parasitic necessity.

Maintaining Badly Written Legacy Code

You have been handed a project or partly developed application to support. Due to prior deadlines, restricted budgets, limited developer skill, multi-developer miscommunication or just plain laziness from some previous developers you have been handed a maintenance nightmare. What steps can you take to improve this situation.

It is likely that you will not get the time to rewrite or refactor what is basically a mess, so small steps and a plan of action is needed:

Do you have a prior list of complaints or help-desk calls that provide an overview of problems and priorities?
Does the code have exception or error handling?
How appropriately named are the variables? I have seen code with variables named aThingList and aColList.
Is the code laid out in a way that makes it easy to understand the flow of instructions? I have seen code that was completely left-aligned making reading to understand it extremely difficult.
Is there an infinite number of exponential loops within the code?
Have you been left adequately written documentation about the application and any code and design decisions that were made.

First you need to tackle any commonly reported application problems. This often means finding the algorithmic cause of problems. Ideally you will be able to run a script over an uncompiled version of the application and replicate the error. Make a copy of any data sources the applications uses so that you can safely manipulate data without affecting the live system the users are using. If you can break into the code during an error or an exception then do so and step through the code line by line until you find the error.

If you cannot break into the code whilst the application is running then you will have to rely upon tracing code movement via a message notification, either using message boxes, writing to a file or writing the algorithm results to a makeshift debug screen. A notification at the entrance of a routine which includes the routine name and the time entered would be useful.

Once you have determined where the error is occurring you will need to determine why?

Is the data causing the problem? The best way to solve this problem is to improve data quality at the datasource. Perhaps an uploaded data file is not up to scratch. Perhaps the user is entering an unacceptable value. Even though the latter could be blamed upon the application's lack of built-in ability to check user input, decisions made during it's previous development phase could have put the responsibility upon the user to enter correctly formatted data which would make this a training issue not a data issue.

== ERROR-HANDLING ==
I have seen numerous applications' code without any kind of exception/error-handling. You need to enter exception/error-handling into routines you know have errors and extraneously long routines. Within error notification you will need to display the routine name, error number and error message. For more information upon error handling see my article Exception/Error Handling, An Integral Part of Programming.

== BADLY NAMED VARIABLES ==
Usually there is not much you can do about a situation where the variable names are less than adequately descriptive of their purpose. Search and replace functionality may help you but usually will not discriminate between variables sharing the same name, in different areas of the cod,e that are used for different purposes. In fact, the renaming of an ambiguous name to a more purposeful name may complicate the understanding of the code where other variables of the same name are affected. The best practice is to write a comment next to the variable explaining it's use for any particular routine within which it is found.

== CRUMMILY LAID OUT CODE ==
Either the code is all left-aligned or dischevelled: Reading badly laid out code is difficult in either case. If you have an editor that automatically indents code based upon language, cut and paste the code into your editor, realign the code and paste back into the application. If you do not have an editor and will be working with this code for some time, perhaps a quickly typed script to clean the code is in order. This is not as hard as it sounds. Basically all the script needs to do is count and add tab spaces whilst reading in each line of the code. If for example your script finds a While statement it adds a tab to the front of the next lines of code it reads in until it finds a Wend statement.

If an application's existing code is particularly ugly and your job is only to add functionality to the application you may consider either removing the old code to a library so you will not have to look at it or build a module as an interface to the old code. The benefit of this is that you will only have to modify your interface should you need to make changes in the future. A added bonus is that you can comment your interface and remove your reputation from the extant disaster behind your it.

== INFINITE DO, WHILE, FOR LOOPS ==
My pet hate! If the code is not inextricably entwined within looping statements then try to reduce the complexity of a routine by extracting algorithms from the loop statements and placing the functionality within separate, smaller routines.

Document your changes via comments within the code or preferably use version tracking software to capture your changes.

== PROCESS IMPROVEMENT ==
Before embarking upon a plan of gradual improvement you need to do some investigation and find out whether there are any projects underway that could replace the application you have been handed. You do not want to waste time and effort patching up an application that will soon be replaced or defunct. Perhaps there are addins to other applications that can provide the same service to the users. Your goal is to get rid of the application if you can or reduce its negative impact upon workload (due to badly written algorithms) by farming out its tasks to better written and more stable applications. Maintenance is an expensive and time-consuming process for badly written applications.

If you cannot rid yourself of the application then write down some steps of improvement, for example; introduce exception/error-handling where it is lacking. Break down seriously long routines. Rewrite extremely bad legacy code that fails to live up to expectations. Remove ugly code to a separate library and access it's functionality by a cleanly written interface. Perhaps you could introduce user input testing or format masks to force consistent data entry.

Sometimes an application produces reports with spurious results due to poorly devised calculations and inadequate testing of SQL string results. Provide users with data dumps in comma separated value (csv) files so they can build their own reports using spreadsheets and charting software (http://en.wikipedia.org/wiki/Comma-separated_values).

Do not be shy in discussing with your users the fact that you have been handed a lemon of an application, they will more than likely agree with you. Inform them on how you intend to implement a plan of process improvement and ask them for their thoughts and ideas. Remind them that it will be a gradual process and involve them in the development and testing. This is called the winning of hearts and minds! This concepts works because it is an inherently genuine and honest approach to improving the situation for your users and yourself.

Do not be disheartened by any user's cynicism towards the services and plans you plan to offer them; When an application produces bad results for any period of time, prior promises upon which the previous developer was supposed to deliver have been broken and it is the user who suffers the results of those broken promises.

Lastly! Expedient support to users' problems will be extremely appreciated even if your plan of improvement is slowed because of it.

Optimizing Your Asp.Net Pages for Faster Loading and Better Performance.

If you read the internet and all of the websites dedicated to Asp.Net you will inevitably read about the wonders of the DataGrid, DataList, and Repeater controls. While each of these has its place, if you are only displaying data there is a much faster and more efficient means to do so.

Let's say you have a page that displays articles based on a query string. Take my article pages for instance. Each article is stored in a database and displayed on the page based on the unique id of the article as stored in the database.

A normal asp page execution procedure goes something like this. The code queries the database based on the Article I.D. and then brings back that information to the page where you display it in the fashion that you would like. This is a fairly straight forward approach with asp and is done all the time.

So how do we speed up our asp.net pages?

Number 1: Use Asp.Net Caching!

This is a no-brainer, and I won't go into the brilliance or details of asp.net caching here because at the time of this writing Google has 2,780,000 articles on the topic. Basically instead of querying the database each time the page is loaded you only query the database once and load that result into the system cache. Subsequent calls to load the page retrieve the data from the cache as opposed to the database which gives you an instant and considerable performance boost. You can then set the cache for how long the cache should store the information as well as many other features. If you are not using the cache, you should be whenever possible!

Number 2: If possible, do NOT use the standard Asp.Net controls.

That's right. The standard asp.net controls are designed for rapid development and not page performance. They allow you to design pages that grab and display data very quickly but their actual performance suffers because of the extra overhead which is there for ease and speed of development time and not page execution speed.

Instead, create either a User Control or even better yet a Web Custom Control which is by far the fastest performance wise and really quite easy to create and use.

Number 3: Use an SqlDataReader or even better yet use a set based command for Sql Server data retrieval and simply execute that one command against the database.

An asp.net SqlDataReader is a fast forward only datareader that closes the connection after it reads the last set of results. Now for my article pages we are only returning 1 particular result. In this case we would opt for the set based command. If you had more than 1 result returned, in your table of contents for instance, you would use the SqlDataReader because you are returning multiple sets of results.

Set based commands are stored procedures that bring back data through parameters as opposed to a result set which then in turn needs to be looped through to obtain your data. So instead of writing your stored procedure like the following which brings back 1 result set:

Select Title, Body, Author
From Articles
Where ArtID = 215

We can write it using a set based command like this.

Create Procedure mysp_GetArticle

@Title varchar(200) Output,
@Body varchar(8000) Output,
@Author varchar(500) Output

Select @Title = Title, @Body = Body, @Author = Author
From Articles
Where ArtID = 215

The above query will return only the three parameters called for and not a result or record set so you don't have to then walk through the returned record set that has only 1 result in it anyway. This second little process of work decreases your performance so you should avoid it whenever possible. Combine this technique with the asp.net cache.

Number 4: Use Classes and ArrayLists as opposed to returning an SqlDataReader.

Create a class and then if there are more than one set of results store those results into individual instantiations of that class. Finally store each of those classes into an ArrayList. You can then store only that ArrayList into the asp.net cache. So instead of getting the results back from a SqlDataReader when loading your page you get them from the ArrayList which is stored in the cache. Nice huh?

Finally... you want to incorporate all of these techniques into your final results which would be performed in the following manner and sequence.

On the first time the page loads, query the database and return all of your data storing it into individual classes. Then store each of those classes into an ArrayList. If you only have one single result you may store only the class into the cache. Then take your ArrayList and store it into the cache.

Next create a Web Custom Control and pass the cached ArrayList to the custom control and loop out your data using the HtmlTextWriter which is very fast. Remember each subsequent call to load the page will be called from the cache which stores your ArraList of classes or your single class.

Certainly it takes a significant amount of additional coding to do it in this fashion, especially when you take proper error handling into consideration, but if you follow this approach your pages will be screeching fast, you will immediately notice the difference, and your asp.net pages will execute in the proper sequence - Data handling in the PageLoad function and the html display in the PageRender function.

Further, you will be glad you did and so will your visitors.

Happy Programming!

Defense Pro By Radware - the Best Computer Defense Available

As the popular saying goes; the best defense is a good offense, so too can it be applied to computer security. To safely secure a computer network a passive firewall is no longer enough. Hackers have learned and adapted their tactics to bypass firewalls and antivirus software. What is needed to defend your computer network is an active and intelligent monitor and defender. Closing off a network to internet can cause companies to lose sales and lead generation on top of which can hamper office productivity.

Before 1999 hackers would work in groups to attack specific targets with flood attacks and shut them down by overwhelming their computers and servers with garbage data. To perform attacks like this required sophisticated coordination and communication, which was difficult because hackers strongly protect their privacy. In 1999, that all changed because a single hacker was able to write software which allowed him to control a flood attack all by himself.

Defense Pro by Radware is the essential piece of hardware to protect against flood and denial of service attacks. Defense Pro is an intelligent tool that constantly monitors and analyzes data packets before they reach your network and servers. Defense Pro's ability to analyze data assures that networks will continue to function even when under attack. Intelligent analysis means that Defense Pro can tell which data entering is important and which data is garbage data. Defense Pro also acts a switch controlling your bandwidth for maximum optimization. By dynamically controlling bandwidth, Defense Pro proactively isolates attack impact to prevent spread to users and applications, while ensuring wire speed forwarding of all secure traffic.

Defense Pro is so much more than a defender of networks. Defense Pro takes an active role in network security and optimization. Defense Pro does all of this with out slowing down the network, in fact Defense Pro built in switch will speed up and optimize your network usage. Do not sit on the sidelines waiting for an attack to happen, go get in the game.

To find out more about Defense Pro please visit for www.radware.com/content/products/dp/default.asp

Windows Server 2003 Active Directory and Network Infrastructure

It is a hierarchical representation of all the objects and their attributes available on the network. It enables administrators to manage the network resources, i.e., computers, users, printers, shared folders, etc., in an easy way. The logical structure represented by Active Directory consists of forests, trees, domains, organizational units, and individual objects. This structure is completely independent from the physical structure of the network, and allows administrators to manage domains according to the organizational needs without bothering about the physical network structure.

Following is the description of all logical components of the Active Directory structure:

Forest: A forest is the outermost boundary of an Active Directory structure. It is a group of multiple domain trees that share a common schema but do not form a contiguous namespace. It is created when the first Active Directory-based computer is installed on a network. There is at least one forest on a network. The first domain in a forest is called a root domain. It controls the schema and domain naming for the entire forest. It can be separately removed from the forest. Administrators can create multiple forests and then create trust relationships between specific domains in those forests, depending upon the organizational needs.

Trees: A hierarchical structure of multiple domains organized in the Active Directory forest is referred to as a tree. It consists of a root domain and several child domains. The first domain created in a tree becomes the root domain. Any domain added to the root domain becomes its child, and the root domain becomes its parent. The parent-child hierarchy continues until the terminal node is reached. All domains in a tree share a common schema, which is defined at the forest level. Depending upon the organizational needs, multiple domain trees can be included in a forest.

Domains: A domain is the basic organizational structure of a Windows Server 2003 networking model. It logically organizes the resources on a network and defines a security boundary in Active Directory. The directory may contain more than one domain, and each domain follows its own security policy and trust relationships with other domains. Almost all the organizations having a large network use domain type of networking model to enhance network security and enable administrators to efficiently manage the entire network.

Objects: Active Directory stores all network resources in the form of objects in a hierarchical structure of containers and subcontainers, thereby making them easily accessible and manageable. Each object class consists of several attributes. Whenever a new object is created for a particular class, it automatically inherits all attributes from its member class. Although the Windows Server 2003 Active Directory defines its default set of objects, administrators can modify it according to the organizational needs.

Organizational Unit (OU): It is the least abstract component of the Windows Server 2003 Active Directory. It works as a container into which resources of a domain can be placed. Its logical structure is similar to an organization's functional structure. It allows creating administrative boundaries in a domain by delegating separate administrative tasks to the administrators on the domain. Administrators can create multiple Organizational Units in the network. They can also create nesting of OUs, which means that other OUs can be created within an OU.
In a large complex network, the Active Directory service provides a single point of management for the administrators by placing all the network resources at a single place. It allows administrators to effectively delegate administrative tasks as well as facilitate fast searching of network resources. It is easily scalable, i.e., administrators can add a large number of resources to it without having additional administrative burden. It is accomplished by partitioning the directory database, distributing it across other domains, and establishing trust relationships, thereby providing users with benefits of decentralization, and at the same time, maintaining the centralized administration.

The physical network infrastructure of Active Directory is far too simple as compared to its logical structure. The physical components are domain controllers and sites.

Domain Controller: A Windows 2003 server on which Active Directory services are installed and run is called a domain con

keep your router secure from hackers and unwanted intruders

Your router is the doorway to your network, control it and you have a pretty good shot at getting access to just about anything else behind it. Large networks usually have a firewall located directly behind the router while smaller networks tend to have a router that serves as both a firewall and router. Regardless of which topology you use this article will help you secure your router and keep the bad guys out.

Cover the basics first. Keep your router in a secured place in your workplace, if it's in a closet, lock the door. Change all the usernames and passwords from the default. I would also suggest not using the same username and password you use for email or network logins. For a username don't use Admin, Administrator or root. For a password use a combination of numbers and letters.

Remote management of routers is usually required but don't open it up to everybody. Telnet is not secure, if you are using Cisco, 3com, Juniper or any other router that utilizes telnet to configure it look into replacing it with SSH. Your router vendor's website should have instructions on how to do this.

Now that you have SSH setup only allow certain IP addresses to access the router utilize SSH. This is one of the most effective security parameters you can do. Limit access only to the computers you know are allowed to access your router. This step is often hard to implement if you use a lot of consultants, although it is worth the effort if it can be done.

Take advantage of maximum logins. Most of the business class routers can deny access for a period of time if an IP address if it has entered 3 bad password combinations. This will prevent a hacker from using a dictionary style attack.

Keep your eye out for updates, but be cautious with them. If your network is running great and hasn't had any problems or security issues, find out what the update does for you. If the update addresses security flaws by all means use it, if it doesn't and you're not having any other issues, I would consider giving it a little a time before you install it.

Nothing is 100% hacker proof, although utilizing these security tips is a great start to help keep the hackers at bay. If you have questions or comments on implementing any of these strategies feel free to send an email to articles@allsystemsup.net. If you need some Network Support for your office give us a call.

Computer Network Management

Today it is almost inconceivable for a business not to have computers, whether it is a construction company or a high technology firm. When a business has more than one computer, they are almost always connected together in a local area network. These networks may be more or less advanced and therefore more or less costly.

Companies invest so much (in terms of both money and time) in a local area networks because there are many advantages that a local area network brings to a business and how it is administered.

Some businesses use a local area network in such a way they are highly dependent on it always working. If the company's network fails, then you may see all the employees chatting away in the corridors because they can't do their work. This means big losses for the company and causes stresses on the employees. All companies must consider their local area networks a vital asset and downtime must be avoided. This imposes huge demands on the network staff to keep such networks running almost 100% of the time.

The advantages of Computer Network Management

One of the main advantages of installing and maintaining LANs is the opportunity they create for better communication and cooperation between employees and customers.

Security considerations: Local Area Network security can be both a help and hindrance. Comprehensive security is beneficial because it provides a central and safe strategy for data access and disaster recovery. All information is protected by the design and implementation of the network security solution. On the other hand, interconnecting computers in local area networks creates a security risk, since doing so makes it technically possible for intruders to access many machines on the network at once.

Cost considerations: Installing a local area network is a relatively expensive project. Servers, cabling, switches, routers and software can all be expensive and should never be purchased without expert advice. Keeping the network operating and secure also requires a lot of resources and can be costly.

Surprisingly, a local area network can bring a number of cost savings. Sharing resources avoids the need to purchase equipment for each individual. Even more important is the security that a local area network can provide. Data loss could cost a business a great deal of money and in some cases, cause the business to shutdown altogether. Computer Network Management should require a consistent routine for data backups with regular checkups of data quality - a practice that will save a company huge sums in the event of a mishap.

Computer Network Management: preliminary analysis phases

The first phase of computer network management is to determine the source of the problem (a preliminary study that looks into several options of differing scope may be useful here) and defining it in a specification of requirements. Examples of what should be evaluated are different network operating systems, mail systems, and other applications. The choice of hardware components should also be evaluated. This phase is generally aimed at establishing what the system should do, not how it should do it.

Computer Network Management: design phase

The purpose of design phase is to determine how the requirements of the specification are to be met. The current approach to large, complex projects is to break them down into smaller, more manageable subprojects.

Computer Network Management: implementation phase

This phase involves the physical installation of the local area network. Cables are run, software is installed, and computers and other hardware are put in place.

Computer Network Management: integration and system testing phase

In this phase, commissioning of the network begins, and routines are adapted to users and the operating personnel. The system must be tested, both to ensure that the network meets the requirements set out in the specification and that it is stable enough to perform the central function it has in the organization.

Computer Network Management: operation and maintenance

Local area networks have complex operating routines. This is because there may be serious consequences when faults occur or unauthorized persons gain access to the system. Many companies have employees devoted solely to take care of running and maintaining computer networks. These system administrators may deal with network issues such as performance, reliability and security of both hardware and software.

Computer Network Management: tools

Although an organization may have computer administrators on site, they must also monitor the network more than eight hours a day. In fact, some of the worst trouble that arises with networks can happen during the night hours when nobody is using the network. With the right computer network management tools, your organization can receive the security of knowing that problems will be foreseen, prevented, and taken care of - and that your network administrator can be notified at a moment's notice, should anything go exceptionally wrong.

Why Adware and Spyware Removal Software is Essential

At night, do you leave your window shades up so the neighbors can watch your television from across the street? Do you let strangers come in and rummage through your kitchen to see if you are purchasing items for a healthy well-balanced diet? Of course not! So, why do you let people tap into your computer, to determine what sites you visit regularly, how you spend your Internet dollars, and programs you have recently downloaded? Now you know why you need to remove all spyware.

So, why do you let people tap into your computer, be able to see what sites you visit frequently and regularly, what and when you have purchased on the net, which programs you have downloaded and when? Why allow anyone access to your personal, professional and financial data? Aren?t these scary enough reasons to make you put in an effort to save your privacy through your computer?

Wikipedia lists Spyware as "computer software that is installed surreptitiously on a personal computer to intercept or take partial control over the user's interaction with the computer, without the user's informed consent". Simply put, spyware is just what its name says ? it is software designed to spy on your computer and internet usage.

Likewise, privacy-invasive software can monitor how you surf the Web in order to redirect you to certain sites, so they will be the beneficiary of your Internet dollars. You are completely clueless, but hackers are laughing all the way to the bank. You are totally unaware that your computer has been under someone else's control.

Not just sending you junk mail, spyware can do a lot of things. It can help the masters of the particular spyware your computer is infected with, to steal sensitive data from your computer. Your personal or financial data, files related to your work, your family pictures? There are a thousand things on almost every computer that a hacker looks for. They might even put your computer to use for their spamming, hacking, or other such activities. Spyware is actually an intrusion into your privacy.

Yes, such programs and activity are completely illegal. However, the internet being a large and complicated network of computers from all over the world, it is hard to monitor it completely and efficiently. The more vigilant authorities grow, the more devious the hackers get. Every day new spyware and other bad programs get released online.

Money can be funneled from your bank account to other accounts before you can even become aware of it. It is not only your computer and financial safety which is put at risk. All your professional and other secure data is also on your computer. You need to make sure that it cannot be stolen by anyone.

Save yourself by securing your computer against spyware by getting a good spyware remover today. They are even available online, some for a small fee and some for free. Take action right now and remove all spyware from your computer. Lead a safer, more scure life.

Heroes of Might & Magic V: Tribes of the East

PRO EVOLUTION SOCCER 2008 PC RIP with Speech Add-on

Minimum system requirements:
Windows xp
Intel Pentium IV
512 mb RAM
DirectX 9..0c video card
64MB Pixel Shader 1.1 (NVIDIA GeForce 3 or ATI Radeon 8500 video card)
DirectX 9..0c compatible sound card
DirectX 9..0c or higher
'..SHCHGB free disk space
8x Dvd- rum drive

Critically acclaimed, multi-million selling and still the most respected football title on the planet, Pro Evolution Soccer continues to be one of Konami?s flagship titles.
The indications are that this latest incarnation will surpass everything that went before it and prove that PES 2008 will be the greatest version of the beautiful game to date.
Two new cover stars will grace the packshot with multiple player of the year Cristiano Ronaldo and England star Michael Owen endorsing the quality of PES 2008 by deciding to use their considerable talents alongside that of the game. As well as the outside having a new look, fans will be eager to know what new changes can be found inside the most important area of PES 2008 – the gameplay.
PES 2008 will feature a brand new intelligence system, called Teamvision, that adapts and reacts to players own gameplay styles to ensure that the computer controlled opponents are always challenging and forcing the player to think and chance their style of play to avoid being out-thought by the game. It will learn counter attacks that target your weaknesses and look to exploit any repetitive tactics players use.
Defenders react better to danger, closing down the ball and charging at shots and the goalkeepers will hold shots that are closer to them as well. Teammates will make more intelligent runs into space and the close control has been sharpened to ensure quick and fluid passing and speedy attacks can be built. The next gen versions will also feature extensive edit modes so players can completely customise their PES 2008 experience.

Football Manager 2008 ISO

Bigger, smoother and more in-depth than ever, Football Manager 2008 is packed full of so much newness it could well take a lifetime to discover every new feature. So we asked Miles Jacobson, Studio Director at SI Games, to take us through some of the changes you'll want to hear about most...

Transfer Center - A new way of managing all current transfer and loan bids for your club, both incoming and outgoing, making it easier to compare bids and reject or accept them.

International Management - The international management gameplay has been completely revamped for Football Manager 2008, including, but not limited to, media improvements, international retirements, player interaction, international scouting, improved national pool selection, captain selection and a separation of international and club morale for players.

Match Flow - The largest change to matchdays in a Sports Interactive game since the introduction of the 2D match engine. Match flow brings more atmosphere to matchdays with match previews, team talks, opposition player instructions, the match itself, half time and post match now seamlessly following on from one another. There's no more pausing to make tactical changes and you'll find a mini-radar pitch whilst making those tactical changes to keep you in touch with what's going on in the match.

Confidence - You can now easily tell what your board and supporters think about your performance in the game through the new confidence section. This gives you feedback not just on your current progress in competitions, but also your financial management and signings.

Easier to Use - A much cleaner skin, a brand new advisor system to help you through various areas of the game, a new notes and notebook system, better button positioning for simpler navigation and an updated tutorial and manual. Also, coach reports to make taking over a new team easier and a new calendar system - which lists all important dates throughout the season - help to make Football Manager 2008 the easiest Sports Interactive game to use yet.

Fan Days - The board can now arrange fan days to boost ailing attendances, or for matches that are likely to attract a low crowd, with a long-term affect to attendances if all goes well.

Match Engine Improvements - A greatly improved match engine, once again utilizing the footballing brain of Ray Houghton and other tools used by real-life managers, to make the most accurate simulation of football in a computer game even more like-life than ever before. Oh, and the ability to change the pitch dimensions at the start of the season to suit your style of play better.

Expanded Media - More media and feedback than ever before, plus more detail in existing media, and a new competition news section to find out what major things are going on in all league competitions.

Regenerated Player Photos - All in-game regenerated players now have pictures using FaceGen technology to give each player more personality. This gives the ability for players to be seen to mature and grow-up looks-wise in front of your eyes as the game is going on.

http://rapidshare.com/files/82817945/Fmanager.part1.rar
http://rapidshare.com/files/82823975/Fmanager.part2.rar
http://rapidshare.com/files/82829325/Fmanager.part3.rar
http://rapidshare.com/files/82834374/Fmanager.part4.rar
http://rapidshare.com/files/82839390/Fmanager.part5.rar
http://rapidshare.com/files/82843672/Fmanager.part6.rar
http://rapidshare.com/files/82844609/Fmanager.part7.rar

Tiger Woods PGA Tour 08 RIP

You’re facing a long putt for par on the 17th hole with Tiger Woods clinging to a one stroke lead. You’ve been in this position before, but that doesn’t matter now. Or does it? Whether you play it safe or go for broke, Play with Confidence in Tiger Woods PGA TOUR 08. The all-new Shot Confidence feature uses factors from your previous rounds - including club selection, lie, hole, and more - to determine your confidence heading into each shot. Play with the confidence of a pro as you battle the best golfers from the PGA TOUR and LPGA Tour on the most courses ever in your quest for the coveted FedEx Cup Championship.

Whats Ripped?
Nothing...just highly compressed and made direct playable

http://rapidshare.com/files/85759650/TigerWoods.PGA.Tour.o8.-rip_maxgrab.part01.rar
http://rapidshare.com/files/85764788/TigerWoods.PGA.Tour.o8.-rip_maxgrab.part02.rar
http://rapidshare.com/files/85770184/TigerWoods.PGA.Tour.o8.-rip_maxgrab.part03.rar
http://rapidshare.com/files/85775518/TigerWoods.PGA.Tour.o8.-rip_maxgrab.part04.rar
http://rapidshare.com/files/85785090/TigerWoods.PGA.Tour.o8.-rip_maxgrab.part05.rar
http://rapidshare.com/files/85794167/TigerWoods.PGA.Tour.o8.-rip_maxgrab.part06.rar
http://rapidshare.com/files/85802410/TigerWoods.PGA.Tour.o8.-rip_maxgrab.part07.rar
http://rapidshare.com/files/85807690/TigerWoods.PGA.Tour.o8.-rip_maxgrab.part08.rar
http://rapidshare.com/files/85813443/TigerWoods.PGA.Tour.o8.-rip_maxgrab.part09.rar
http://rapidshare.com/files/85817840/TigerWoods.PGA.Tour.o8.-rip_maxgrab.part10.rar
http://rapidshare.com/files/85819338/TigerWoods.PGA.Tour.o8.-rip_maxgrab.part11.rar

RAR Password:
www.maxgrab.org

Installation Notes:
1.: Unrar and double click: c:\TigerWoods\TiWo08.exe ( must be done!, adds reg. keys! )

3.: double click: c:\TigerWoods\MakeDesktopIcon.exe + run game with desktop icon.

( this game *must* be extracted to drive C: > extract to... and choose c: )

The Witcher Rip

Civilization IV - Warlords RIP

Civilization IV - Warlords

An all-new expansion pack, Warlords pays homage to some of history's greatest military leaders, delivering six new scenarios, giving players the chance to change the course of history with the help of their new powerful "warlord" unit. The expansion pack is loaded with new civilizations, new leaders and more units, resources and wonders that can be used in both single and multiplayer games.

By: 2K Games, Firaxis Games
Genre: Historic Turn-Based Strategy
Players: 1-12

http://rapidshare.com/files/55381208/Civilization_IV_-_Warlords.part1.rar
http://rapidshare.com/files/55381585/Civilization_IV_-_Warlords.part2.rar
http://rapidshare.com/files/55381831/Civilization_IV_-_Warlords.part3.rar
http://rapidshare.com/files/55382057/Civilization_IV_-_Warlords.part4.rar
http://rapidshare.com/files/55382078/Civilization_IV_-_Warlords.part5.rar

Hospital Tycoon 2007 (ISO)

Published by: Codemasters
Developed by: Deep Red Games
Genre: Simulation
Number of Players: 1

Hospital Tycoon is a medical-themed sim in which players are put in charge of hectic hospital facilities that are constantly on the verge of crisis and collapse. Players are challenged to run, maintain, enhance and expand the hospitals while turning any chaotic situation around using ingenious management techniques. The game's high level of character interaction is full of humor and drama, creating living hospital that's part soap opera and part comedy. Players will direct the hospital's medical staff, ensure patients are cared for and have the treatment facilities required. There's also the upkeep of each hospital to control and develop; dedicated areas can be built to support additional medical needs – surgery, diagnosis, physiotherapy and more. The more patients that are cured the more your medical empire can grow and flourish, but watch out for the spread of infectious conditions, or you'll soon have an epidemic plunging the hospital into absolute chaos.