Windows Domain Controller and their Roles

I really favour Linux/Unix working environmental but sadly commercialism has engulfed our societies as the likes of Windows platforms while the former one doesn't matter how much is rated high still lives in the shadows. And now I have to grasp the Windows lingo all along to fit in an organization. So lets learn something about Windows Domain Controller and their roles.

Before going into any details first its important to understand the differences between the following terms.

• Active Directory: is a directory service that serves as a central location for network administration and security which is responsible for authenticating and authorizing all users and computers within a network of windows domain.
• Forest: is the top-level container of Active Directory (AD) infrastructure. Can contain one or more domains. These domains are interconnected trough a transitive trust. A forest shares a single schema database.
• Domain: is one level below AD forest. Can consist of one or more Organizational Units (OU). A domain shares a single administrator group and same set of objects.
• Domain Controller: A domain can consists one or more domain controllers (DC). A DC holds a directory DB of its perspective domain. The directory DB consists of user, objects, computer objects or more.
• Organizational Unit: is a container within a domain and is used to organize set of users and computers. It is helpful in implementing set of policies to a group, user or computer within a domain.
• Windows DC: A server running the version of Windows Server OS and has AD installed on it and is responsible for allowing host access to Windows Domain resources.

Now coming to the roles; there are specialized DC roles that perform specific roles in Active Directory Domain Services (AD DS) environment. The specialized roles are:

• Global Catalog Servers: A DC designated as a global catalog server stores the objects from all domains in a forest. This is usually the first DC in a forest. Later on other DC can be specified as global catalog servers.
• Operations Master: This is a DC that is designated to perform specific tasks to ensure consistency and to eliminate the potential for conflicting entries in the AD DB.

AD DS defines five operation master roles called:

1. Schema Master: Responsible for propagating changes to all DCs within a forest. Changes regarding schemas required throughout forest should be made on DC serving as schema master. There can be only one schema master in a forest at any time.
2. Domain Naming Master: It is required to keep track of all the domains within an AD forest. The DC with domain naming master is accessed whenever domains are address/removed from a tree or forest. There can be only one domain naming master per forest. It ensures that no two domains have the same name existing in the same tree.
3. Relative Identifier (RID): Allocates blocks of RIDs to each DC in a domain. When a DC creates a new security principal (user, group etc.) it assigns the object a unique security identifier SID. The SID contains a domain SID which us same for all the security principals created in the domain and a RID which uniquely identifies each security principal created in the domain.
4. Primary Domain Controller (PDC) Emulator: PDC receives prefential replication of password changes that are performed by other DCs in the domain and is the source for latest password information. It's also the default time source.
5. Infrastructure Master: is responsible for updating object references in the domain that point to object in another domain. It updates object references locally and uses replication to being all other replicas of domain up to date. Object reference contains GUID global unique identifier, distinguished name and possible a SID. The distinguished name and SID on object reference are periodically updated to reflect changes made to actual object.

- Schema Master and Domain Naming Master performs operations that must occur on only one DC in the forest.

- PDC, RID, Infrastructure Master perform operations that must occur on only one DC in a domain.

HEC Dissolution to Provincial Level.

The Higher Education Commission of Pakistan (HEC) in now dissolved to provincial level. Former chairman of HEC and the pioneer of lucrative educational policies Dr. Atta Ur Rehman is terming this as a "National Disaster." In an interview on a private news television channel he mentioned some the most obvious reasons for this dissolution which are:

1. To avoid degree scrutiny by our political leaders as member of the parliament needs to hold a graduate degree. The verification of these degrees was given to the HEC and as a result created a rift between the commission and the political circles.

2. To get illegal access to huge lands owned by different universities around Pakistan.

3. To further practice corruption within the education sector and to nurture respective political ideologies. As after this, it will be the provincial regulatory committees responsible for the provision of scholarships, grants and to oversee state and private universities. As a result, it would be soon that one would be able to find two-room universities in different corners of the country nurturing different political ideologies.

Now as a graduate myself in Pakistan and hoping to pursue my doctorate studies here; What do students like me fear? To start with, HEC now working as cells around Pakistan would lose its centralized transparent structure as we already have seen how incompetent our provincial structure is. Thanks to the 18th amendment of Pakistan constitution; which is dubbed to be the best thing happened to Pakistan since the 1973 constitution but only if we had a reliable strong political structure. Given the present scenario everyone is aware how dire this step is and what consequences we would be visible in few years time.

I also fear the the different grants and scholarships available to the Pakistani students from different governments and organizations around the would would be stopped. Its has been only few hours since the news of HEC dissolution is announced and already we had a statement from the present HEC chairman Dr. Javaid Laghari that the USAID and World Bank has stopped their aid which sums up to about $550 billion that was to be used by HEC for the coming 5 years to carry out different projects. Apart from these future promises, the present structure of the commission in question is also uncertain of its future like the HEC Digital Library and HEC e-learning.

Now the interesting thing would be to see how the nation responds to this. Dr. Atta-Ur-Rehman and Dr. Javed Leghari are already appearing on different news channels to sum up these mentioned facts to the nation. What matters now is would there be someone to carry out any action on this unfolding situation. I hope and I pray that there would be some patriotic Pakistanis among us that would stand up to this matter and do justice with it.

Mobile Communication Technologies for Dummies.

Different communication technologies and then the different standards between countries and upon it the non-stop introduction of wireless gadgets often makes me confused and eventually I mix up the concepts. Now I decided to make myself a simple/easy to understand table for a quick review of these technologies.

Generation	Name	Year	Frequency	Data Rate
1G	AMPS – Advanced Mobile Phone System (using FDMA)	1980’s	800 – 900 MHz
1G	D-AMPS – Digital AMPS (adding TDMA to AMPS)		800 – 900 MHz
2G	IS-95 (using CDMA)	1990’s	800 MHz
2G	GSM – Global System for Mobile Communication (using TDMA)	1990’s	900 – 1800 MHz
2G	GSM GPRS – General Packer Radio Services (by 3GPP*)	2000		144 Kbps
2.5G	1xRTT – One Time Radio Transmission Technology (by 3GPP2**)	2002		144 Kbps
2.5G	EDGE – Enhanced Data GSM Environment (by 3GPP)	2003		384 Kbps
3G	UMTS – Universal Mobile Telecommunication System	2002	1885 – 2025 MHz	1.92 Mbps
3G	UMTS HSDPA – High Speed Downlink Packet Access	2002		14.4 Mbps
3G	EV-DO – 1x-Evolution-Data Optimized (using CDMA) (by 3GPP2)			2.4 Mbps
3G	EV-DO Rev. A (by 3GPP2)			3.1 Mbps
3G	EV-DO Rev. B (by 3GPP2)			4.9 Mbps
4G	UMB *** – Ultra Mobile Broadband (by 3GPP2)			288 Mbps downstream
4G	LTE – Long Term Evolution (by 3GPP)	2009	1920 Mhz – 3600 Mhz	100 Mbps downstream 30 Mbps upstream

* - 3GPP 3rd Generation Partnership Project. Body responsible of up-gradation of GSM networks in Europe, Japan, North America, South Korea.

** - 3GPP2 3rd Generation Partnership Project. Body responsible for up-gradation of CDMA networks in US (also South Korea and Japan.)

*** - Instead of adopting UMB, it has now been decided favoring LTE instead by the service providers.

4G is currently implemented in Sweden and South Korea. UK has recently declared licenses for 4G service provision. While in Pakistan 2.5G EDGE is currently implemented but not a single provider has upgraded to 3G. Huawei did implemented a couple of experimental 3G sites but its not sure where some operator would adopt it in near future.

P.S: Stuff here has been collected from various online resources and there might be some errors. So please do point them out so I can correct them.

Executable Bit: Wine error in Ubuntu 10.10

If you are bothered by the Windows .exe files execution under the Wine in Ubuntu 10.10 and getting this error:

Blocked: wine start/unix

The file '/media/My Passport/Softwares/Setup.exe' is not marked as

executable. If this was downloaded or copied from an untrusted source, it may be dangerous to run. For more details, read about the executable bit.

Then you are at the right place. Just do the following:

1. Copy the .exe file to your system (home/desktop: Just to make it sure the file is not on a removable media.)

2. Right click on the .exe file. Click Properties.

3. Click Permissions tab.

4. Check the option: Execute: Allow executing file as program.

5. Close and run it.

You would able be execute it without any errors this time with Wine.

"Mapping of User Quality-of-Experience" published.

So it is official now. My research findings are now published by Lambert Academic Publishing. So super excited to receive my first copy any day soon. If you are interested in this area of study you can get your self a copy here.

ISBN-13: 978-3-8433-8978-5
ISBN-10: 3843389780
EAN: 9783843389785

Research Findings.

I started this blog to share my academic achievements I endured during my Masters studies back at Sweden. I wanted to share some interesting results here but due to lack of time I was not able to. Now finally I have decided to give it some time daily and share a topic or two which has some research potential on this platform. I will follow a step by step procedure here based on my research findings in my Master Thesis. Once completed, I will share my ideas on how the work can be extended and carried on. Some of the upcoming blog posts would be:

- The need for mapping user experience to application perceived performance.

• - The plan and what aspects were considered.
• - The implementation and experimentation.
• - The results (which would be divided into many sub posts.)
• - Future work.

Am excited and hopeful that not only this blog will catch interest of QoE/Ux enthusiastic but will also polish my skills and help me get recognized on other platforms I sought for my career.

Social Categorization – Visibility and Invisibility

She just stood there at the front, pointing to the power points slides lit by a projector. The participants were just listening, many of them dozing just like me while the beautiful mid thirties lady just went on discussing the different aspects of social categorization. While discussing one of the aspects of whether social categories can be visible or invisible, she proceeded with a personal example. She just told it to out face. “I was a prostitute for one year in Dubai in the mid nineties.” These very words from the elegant lady mouth landed like a spell on fellow participants. All were just staring at the face of this lady who was just scrolling her eyes around the room with her mouth closes, her face color turned red with sparkling eyes as if tears would start flowing from them any moment. The next 10 to 15 seconds turned the seminar room of almost 40 participants into complete quietness that you could hear the sound of wall clock perking through your ear drums. She was the first one to break the ice by saying “No I was not!” which came as a relief to everyone that as figuring from how sweet this lady was, it would be such a cruel injustice of her being a social taboo. She went on clarifying that she was considered to be a prostitute when she was on her own working for a firm in Dubai in the mid nineties which saw a peak in prostitute business when the local Sheikhs were pretty much fond of getting the taste of blondes from the Europe. She went on explaining on how she learnt few words in Arabic to woo passersby away when cards used to stop for her on the road. And how she would lower her gaze when people used to stare her being as the scum of the society. She explained this one incident that brought her to tears when showing her love to a small kid at a shopping mall, the kid’s mother came around and pulled the child away from her and kept on babbling in Arabic that not to socialize with her as if her invisible social taboo is like a contagious disease that would spread even by affection. She called that year the worse she has ever felt in her life and this made her to resign from her job and leave the country.

She asked whether we have been victims of such invisible social categorization being entrusted upon us. She only had to ask this question for a sea of responses that were to unravel from the participants. We being the social victims? Of what part of our 2 plus years of stay in Europe has made us felt socially acceptable? The conditions might have changed in Dubai at the month for European blondes to be considered prostitutes. In present years a lady with blonde hair would be most likely to be taken for a touring and the only exploitation she would be getting would be from shopkeepers looking for a healthy bargain. But on the other hand brown skinned people like us would find the situation deteriorating day by day in this part of the words. Called by names such a garlic people or paki –whatever you can add with that is been a routine situation which browned skinned people like us have to live through. The very fact that you have to hide your green passport while standing in airport queues just to avoided unnecessary attention you might get from the security. So invisible social categories, where do we fit in now?

Sorry for sounding so naive but I needed to get this out of my system.

Pictures are from Pic 1 and Pic 2.

The lives you live; in the game of life - Sunday Scribblings

Being experimental with life, it always happens that you get to play games or you ought to play games at some crisscrossing highway sections of your life. I happen to play games as well, and am still playing them now. It not that I always realize that this is the game I am playing. The realization comes a little after there comes this GAME OVER sign in front of you and you just realized

that it really was a game.

Today I would be telling you about some of the games I played and keep playing in this life of mine.

The most comprehensive game I still keep on playing is with my supreme Divine. The more I keep telling myself that this isn’t a game, the more it turns out to be a competitive challenge. I move on doing the tasks laid down for me. Sometimes I blink and pass on a few unattended chores, hide from them until you get to that point, you have pretty less life support left to play with and you run again to the chores and tasks laid down for you by the Divine. It also happens with me, a secret of my life I haven’t relieved till now, I put myself to a task, and challenge myself that if am not able to do it, It would be the end for me. And yet I stand up to the challenge. Very less I don’t succeed in it; not that am a pretty hard challenger or that I have that courage and support to stand by it, but it’s the nature of the task that helps me get through it. Still am often out of my breath and sweating as if mid of some Arabian desert.

Another game I found myself playing since past decade or so would be turning a blind eye on entities striking against my moral belief or my self-integrity. The question arises and why I do that. The only answer that keeps echoing in mind is I SIMPLY DON’T WANT TO! Call it fear or call it insecurity. Its ME.

In life there had been numerous times I found myself on cross roads. And I did take decisions. Sometimes by myself; Many times guided by other people. Sometimes I repented them but most of the time I felt completely at home by those very decisions. And that should be the important part of it.

Then there are the multiplayer games which ought to be the favorite category of most of the people for sure. Sometimes the results might not what we always expect. But the thing is how we value those expectations keeping in mind the results we achieve. Sometimes you win, sometimes you lose; maybe both frequencies are not the same. But still we should be thankful at least we are part of the game. Look around; how many people are still left with playing the solo games. These games can be competitive and sometimes can be strategic as well and that’s when partnership plays an important role.

Be it which so ever kind of game, it doesn’t matter that you win or lose it. But the important thing would be that when that sign of GAME OVER comes in front of you, you must be sure no one gets hurt and you for sure have left a smile on every participant face.

Credited to Sunday Scribblings.

The pictures are from Pic1 and Pic2.

Its official!

• So its official now. And this email will explain how (:

Hi!

On Wednesday the 2nd of December at 9 o'clock (9:00~12:00) we'll have three MSc. Thesis defense's in 3235A at Campus Gräsvik. Below, you will find the thesis titles and abstracts.

Welcome!

/Patrik Arlos


Performance Of 3G data Services Over Mobile Network in Sweden, Ravichandra Kommalapati.

The emerging technologies in the field of telecommunications enable us to access high speed data services through mobile handsets and portable modems over the mobile networks. The recent statistics also shows the use of mobile broadband services are increasing and gaining popularity.

In this thesis we have investigated the impact of packet size and data rate on one way delay and packet loss in operational 3G mobile networks through network level measurements. To collect the network level traces an experimental testbed is developed. For accurate measurement Endace DAG cards together with GPS synchronization is implemented. Results were gathered from three different commercial mobile operators in Sweden. From the results it was concluded that the combination of maximum packet size and data rate resulted in minimum one way delay. It is also observed within the big packet size category, that the percentage of packet loss is less as compared to the smaller packer sizes. Such findings may prove e±cient for application developers to make the post of the UMTS network conditions.


Bitrate Analysis On First Person Shooter Games, Bandaru Lokeswara Rao.

Multiplayer games are prominent now a days. In recent years real time multiplayer networked gaming has grown in popularity due to exciting challenges posed in by competing with human opponents. One of the types of multi player games is First Person shooter games. FPS games are becoming popular predominantly over wired networks. In FPS games delay, bitrate and inter packet arrival times has major roles because they determine who wins and loses the game.

This thesis investigates the behavior of bitrate at different parts in the network and at different time scales, which involves analyzing of bitrate traces in each relevant stream of the disturbed network in the game i.e. identification of when the disturbance occurred in the traces, identification of what IP that was disturbed and simple statistics are made at different locations of the stream at same sample frequency. Finally we analyze the behavior of bitrate at different parts of the network and with the help of the statistics made out of them, we compare to the user experience. How the user felt at each and every second while playing the game and how experienced he is in playing the games is been considered and compared with the data which was already collected before in the Dream Hack winter 2007, Tele Communications department of Blekinge Institute of Technology, Sweden.This results thus suggests at which bit rate the network should flow in order to satisfy the end user, as the quality of experience that counts at the last.

Mapping of User Quality-of-Experience to Application Perceived Performance for Web Application, Ashfaq Ahmad Shinwary.

Data services prove to be integral part of the Internet today of which web browsing stands out to be the popular user activity. User perceived quality of web browsing can be affected by delays in the network that can result in higher application download times. Quality of Experience is of highly subjective nature. Majority of the work done is this regard managed to map network metrics to Quality of Experience but the relationship between user perception and application quality was always in vague.

In this thesis work, an effort has been made to map applications metrics to Quality of Experience. A subjective analysis on how the user takes into account the domain of web browsing has been carried out. For this purpose a testbed was developed at Blekinge Institute of Technology on which different users were tested. Specific sequences of delays were introduced on the network which resulted in desired application download times. Conclusions were made by stating that user experience in web browsing is affected by application download times. It was found that user Quality of Experience ratings for download times of more than 3 seconds deteriorated which eventually leads to the conclusion that a user is not in favor of tolerating application download times of more than 3 seconds. Furthermore there exists an exponential relationship between Quality of Experience and application download times.

Patrik Arlos,
Ph.D Telecommunications systems,
School of Computing,
Blekinge Institute of Technology.
Karlskrona, Sweden.

LaTeX Figures

One of the biggest problem that has given me a really hard time while using LaTeX is the use of figures. Most of my figures always were MS Visio drawings. As LaTeX accepts figures in PS or EPS formats, so the normal conversion methods mostly resulted in poor image quality. Googling it I was able to find there are numerous methods. some long, some hectic; most of which didn't worked for me. So here I would be telling you a pretty simple method for conversion of MS Visio images to standard PS formats that can result in high qulaity images for you to use in your LaTeX document provided you have a professional Adobe Reader (any version) and the MS office SAVE AS PDF plugin. Just follow these steps.

1. When you Visio drawing is ready, make sure the page setting is as follows. Goto FILE> PAGE SETUP> PAGE SIZE TAB> there make sure the check box SIZE FIT TO DRAWING CONTENTS is enabled.
2. Make sure you have the Visio to PDF plugin installed. You can get it from http://www.microsoft.com/downloads/details.aspx?FamilyId=F1FC413C-6D89-4F15-991B-63B07BA5F2E5&displaylang=en
3. Once you have the plugin installed. Goto File and click PUBLISH AS PDF or XPS.
4. Now open the PDF file you just created. Once the drawing is opened, saves this as a PS by clicking FILE> SAVE AS and from file format select POST SCRIPT (PS).
5. You are done and ready to use the generated PS image in your LaTeX document (:

PS: Always use Enhanced Metafile (EMF) images in your MS WORLD/POWERPOINT documents as they give you a petty high quality resolution.

EDIT Phase

So far i was of the belief that am finished with my report writing. But thoughts can lead to deception. Couple of days ago i my report was hand over to me after being reviewed by two scholars and boy I really detested the way they put corrections on my writing :( Well anyways before am able to report some of the main contributions here; will have to deal with this finishing of the report once again. This is so tormenting. I was planning to write a paper about it but well; plans are plans!

Linux vs Windows: ISSUES?

Linux vs Windows

From time to time since my relevance with computer knowledge; I been asked a question that Why is Linux preferred over Windows when it comes to main stream network management? I always used to give them crap that Windows GUI is so graphic intensive or Linux had this endless server management capabilities and so on. These points might hold somewhat little significance with the facts but still a scientific proof was needed; even to satisfy my own self inside.

Until a few days ago while carrying on the work on my dissertation (Mapping of User Quality-of-Experience to Application Perceived Performance for Web Applications). It involved capturing of network traces. In order for our time stamps to be very highly accurate; Our professor implemented that we should use the NTP (Network Time Protocol) in order to synchronize all the clocks of machines involved in our experiment. Hence the computers were synchronized to the pool servers available on the NTP.ORG.

At this point it would be useful to inform you that it was a client server setup; our servers were running Linux OS and Windows XP was running on the client. Now that we had synchronized all the clock on the computers with the help of NTP. To get the scientific proof; we compared how much synchronized the clocks were. Again the genius our professor is; he had this tool designed in Perl for comparison of the system clock to see how much they were synchronized with respect to the reference server (i.e. the NTP pool servers).

I would share some statistical results taken form that tool. In the following graph the comparison between the different computers are shown.

Blue and red lines represent a Linux system while the Green represents a Windows XP system. As visible the greenery is all over the place. This graph basically shows how they systems are synchronized with respect to the reference server. On the Y-Axis the deviation between the computers is given in seconds. While on X-Axis time probes are illustrated. Evidently from the graphs the Linux Systems are the most synchronized ones deviating less than a couple of milliseconds from the reference server. While there is a very strange behavior shown by the windows system.

At this point I remembered a news article that appeared online which reported “London Stock Exchange to abandon failed Windows platform” (Available Online: http://blogs.computerworld.com/london_stock_exchange_to_abandon_failed_windows_platform ).

Now next time when some one asks me why is Linux preferred over windows in main stream server management; at least I would not give them any crap :D

DummyNet (KauNet) Delay Behavior

I had to encounter the DummyNet Network Shaper today for some experiments. I had heard it did had some trust issues but was surprised to see it was beyond the limit of trust. Just for an idea let me show you the readings I got for different delay settings. For the experiment I had to emulate the link between the client and the server that was connected to the internet. The delay was implemented on the downlink traffic only. Following was the behavior i caught. The X-Axis is displaying the number of web pages and the Y-Axis is displaying the take taken to load the page in seconds.

For a 250ms delay.

For a 500ms delay.

For a 50ms delay

For a 100ms delay.

For a 0ms delay.

Dual Monitors in Linux with NVIDIA (kubuntu, ubuntu)

Making dual monitors to worik with Linux was what I dealt with today. I was even bribed with a golden star by my professor; if i found a solution to it! And guess what; I go it !! :D

So the solution to it is! ...

Simply go to the terminal.

Make sure you are root mode.

First make sure that the driver is propely installed. Run the command in terminal

$ sudo apt-get install nvidia-glx

Now comming to the configuration; type in the terminal

$ kdesu nvidia-settings

or if kdesu is not supported replace it by "gksudo"

$ gksudo nvidia-settings

This will make the Nvidia X Server Configuration Module load. From there goto

X Server Display Configuration

There select option TwinView in the Configuration Tag.

Click Apply. And you are done!

Don’t forget to click "Save to X Configuration File".

CiaOo...

FireFox - Page Rendering

Few days ago I needed to customize my FireFox (FF) for an experiment I was performing. I wanted to test users for different delay thresholds. I also wanted to try the users with different page rendering scenarios. One of the scenario was that how would user react when the page is loaded at once (instead of incremental leading as is followed by many browsers today).

After a lot of peeking in the about:config tab of FF, intensive googling & numerous forum posts and even chat with the FF support groups, i didn’t found the answer to this very tweak. But in the end i was able to carry out the intended task with another method.

As FF uses the Gecko Page Rendering Mechanism, it follows the concept of flows which makes the FF loads a page after intended milliseconds of delay, till this time whatever data has been received; it’s displayed in the browsers. This flow delays is set in the "nglayout.initialpaint.delay" preference available in under the about:config tab. If you don’t find it there it means that its using the default setting of 250ms.

Many people misunderstand preference and always set it to 0ms as they think the browser will perform faster. It might seem to perform faster but in reality it does not. The MozillaZine knowledge base mentions that "Lower values will make a page initially display more quickly, but will make the page take longer to finish rendering. Higher values will have the opposite effect." which is true.

Anyhooo coming back to the topic. I found that if we increase this value to the maximum, the page can be loaded at once when its completely downloaded which was the exact thing I wanted :D hence I was able to perform my experiments. The page will be loaded before the timer gets expired given if the page has already been downloaded. The purpose of posting this here is that I found this similar question asked again and again by FF users. They may find this entry useful as well.

Working on my dissertation.

This happens when you are nearing the end of your degree; & so am I. After a whole complete year here at Sweden, i have managed to finish the course work of my Master's in Science degree. It's now time to formally end it with a final dissertation. Still have some month to work on this dissertation but am thankful to be at level with the course work. About the dissertation; was lucky enough to be selected with a honorable professor Patrik Arlos at my own university. Things might be tough because of research nature & the high quality as demanded by the professor; but am up for the challenge. Let’s see how it goes (:

Dissertation title: Mapping between Application Perceived Performance & QoEWeb.

Will be doing it in LaTeX; so that’s why am peeking so much into LaTeX blogs lately *Giggle*. Wish me good luck!!

CiaOo