Publicado por: heldercangula | Abril 14, 2015

Toyota Prius Hybrid – BOS

Toyota Prius Hybrid – BOS

Blue ocean strategy is about how any company or organisation can break out of the red ocean of bloody competition or existing industries and create uncontested market space that makes the competition irrelevant, (Mauborgne,2011).

Toyota, the Japanese auto maker reputed for its process innovation, as it developed the Lean Manufacturing and Just in Time manufacturing philosophies. Toyota is also reputed for Toyota Way, collective managerial values and business methods the company pioneered over years and the company is reputed for its quality manufacturing and production.

Kim and Mauborgne offered one of the suggestions in how to begin creating blue oceans by: Reduce your costs while also offering customers more value. One of the example they referenced in the book is the Toyota Lexus, which was launched in USA in 1989 with the price at that time lower of the Cadillac and Lincoln models but with features and quality of the high-end BMW and Mercedes.

The car was launched at  a price less than 20% of the price of BMW and around 35% of the price of the Mercedes respectively. The car became big hit for the company and it made a mark in the United States market as the company was a Japanese company facing tough competition from US auto giants General Motors and Ford Motors. Toyota created a new space of affordable luxury car market and it dominated this uncontested market and steadily built market share in tough US car market. This reflects on what Kim and Mauborgne described as competition. Kim and Mauborgne argues that, ‘’Competing in overcrowded industries is no way to sustain high performance. The real opportunity is to create blue oceans of uncontested market space.’’

Toyota pursuit of Blue Ocean strategy resulted in the launch of Toyota Prius in 1997 which is a full hybrid electric mid-size hatchback, the first mass produced hybrid car and the car is rated as the cleanest car sold in the United States, which was launched in US in 2001. The company sold close to 4 million units and more than half of the sales come from the US market.

Toyota management had encouraged the development hybrid concept car that works on both gasoline and electricity and the current models also include the full electric car. Toyota Prius series created a new market segment of consumers who are highly environmental conscious and also gave an opportunity to all those consumers who wantto focus on  saving the environment as global warming due to carbon fuel emissions had become a major concern worldwide.


50 Lessons, (2011b) Overview: Blue Ocean Strategy: Interview with Renee Mauborgne, [Media], Dublin: SkillSoft

Kaila, R. P., (2014) ‘Blue Ocean Strategy – Toyota Hybrid environmental friendly Car success’, Available at:, (accessed:14/04/2015)

Kim, W. C., & R. Mauborgne, (2004) ‘Blue Ocean Strategy’, Harvard Business Review, 82 (10) pp.76-84. Retrieved from

Publicado por: heldercangula | Abril 2, 2015

External Environment Analysis of Starbucks

External Environment Analysis of Starbucks

Starbucks Corporation is an international coffee and coffee house chain based in Seattle, Washington, United States. It opened as a single small store opened in 1971 and became a coffee giant at the end of the millennium. Starbucks has led a coffee revolution in the United States and beyond. The store was opened by 3 men: Jerry Baldwin, Zev Siegl and Gordon Browker.

Starbucks locations serve hot and cold beverages, whole-bean coffee, full-leaf teas, pastries, and snacks. Most stores also sell packaged food items, hot and cold sandwiches.

Starbucks is the leading and most major name in promoting coffee throughout the world. They have expanded continuously and it has resulted in their growth and popularity. Starbucks revenue is generated both from company-operated retail stores and from specialty operations.

Michael Porters 5 Forces:

According to Porter’s, ‘’Awareness of the five forces can help a company understand the structure of its industry and stake out a position that is more profitable and less vulnerable to attack’’.

The five forces that affect the company in any industry include the competition, the suppliers, the customers, the threat of new entrants and the threat of substitutes. The porters five forces analysis for Starbucks in UK is given below:

Rivalry among established companies:

The coffee industry is fragmented. None is dominant in the industry. Today, Starbucks have over 21,536 stores in 64 countries. Starbucks’ competitors for coffee beverage sales are quick-service restaurants and specialty coffee shops, such as Nestle, Costa,

Dunkin’ Donuts. In 2010, Costa coffee took over Starbucks and gained the biggest market share in England. The other challenge Starbucks face is posed by Nestle coffee. Differentiated from Starbucks, Nestle uses the low price to attract customers, whose price is one fifth of Starbucks’.

Threat of New Entrant:

The innovation and product differentiation can be brought in by new entrants.

Threat of Substitutes:

There are many substitutes, offering similar services and also taking a share of the market available to Starbucks. Starbucks’ biggest potential competitors are the fast-food leading corporations like McDonald and KFC. Both of them have the economic scale as they opened up stores in all over the world and had much more distribution centers. It is easy for them to launch into the coffee industry and take market share from Starbucks.

Bargaining Power of Suppliers:

Starbucks is dominant in doing business with its providers. The number of the coffee bean providers is large, so Starbucks can be strict with the quality of the coffee beans and lower the coffee bean prices.

Bargaining Power of Buyers:

Consumers choosing Starbucks isn’t on the basis of the price but the comfortable environment, high quality of product and its service.


Starbucks was negatively impacted by the external environment factors .Starbucks has had much market power in the gourmet coffee industry.  They have attracted customers. In the current economic state, their prices have caught up to them causing their demand to decrease.  People do not want to spend their limited income on premium coffees that they can get from any of their competitors, like Dunkin’ Donuts, Nestle, McDonalds and Panera Bread. Starbucks has been forced with the changing times and the economy to drive down their prices to compete in the industry.


Liz, (2013) ‘Starbucks’ External Environment Analysis’, Available at:,(accessed: 1/04/15)

Pitek, M., (2009) ‘Competitor Analysis’, Available at:,(accessed: 1/04/15)

Porter, M. E., (2008) ‘The Five Competitive Forces That Shape Strategy’, Harvard Business Review, pp.2-4, Available at:,(accessed: 1/04/15)

UK Essays. November 2013. Internal And External Market Analysis For Starbucks Marketing Essay. [online]. Available from: [Accessed 1 April 2015].

Publicado por: heldercangula | Novembro 7, 2012

Publicado por: heldercangula | Julho 24, 2008

Norton Ghost

Bem,estando a colaborar neste momento com um grupo de Engenheiros Infórmaticos de nacionalidade espanhola na configuração e instalação de um software por eles Desenvolvido em 200 portateis ACER e TOSHIBA fui – me forçado a publicar este artigo sobre o GHOST que é uma ferramenta que ajuda muito.e sabem porque? porque imaginem voçês configurar 200 portateis para serem prontos em dois dias e sem o ghost.?

Software da empresa Symantec, esse software faz copias de HD ou partições do HD. Depois é possível restaurar o backup, mesmo que seja em outro computador.

É um excelente programa, para quem trabalha com manutenção de informática e de redes. Pode-se fazer um backup de uma máquina com todos os drivers e programas instalados, se algo der errado não precisará reinstalar todos os programas e drivers e o sistema operacional tudo de novo.

Você fará uma imagem, cópia fiel de seu HD ou se uma partição, com este programa. Para restaurar a máquina basta que de posse da imagem, em um HD portátil por exemplo, voce faça um boot do Norton Ghost que em 15 minutos você terá sua maquina completamente restaurada e com tudo que você precisa, com todos os arquivos e backups do ponto onde você fez a imagem.

Publicado por: heldercangula | Julho 24, 2008


Bem visto que os IP’s da versão 4 (ipv4) serão substituidos pela versão 6, num futuro muito proxímo decidi, postar este tutorial muito bom sobre IPv6.espero que possam gosta-lo:


Origem: Wikipédia, a enciclopédia livre.


O IPv6 é a versão 6 do protocolo IP. O IPv6 tem como objetivo substituir o padrão anterior, o IPv4, que só suporta cerca de 4 bilhões ( 4 x 109) de endereços, enquanto que o IPv6 suporta 3.4 x 1038 endereços. A previsão atual para a exaustão de todos os endereços IPv4 livres para atribuição a operadores é de Abril de 2010, o que significa que a transição da versão do IPv4 para o IPv6 é inevitável num futuro próximo. O governo dos Estados Unidos da América determinou que todas as suas agências federais devem suportar o protocolo IPv6 até 2008.




Motivações para a mudança de IPv4 para IPv6

  • Espaço de endereçamento. A maior parte dos endereços no IPv4 são de classe C, que são muito pequenas para muitas organizações, os endereços de classe B estão praticamente esgotados.
  • Qualidade de serviço. A convergência das redes de telecomunicações futuras para a camada de rede comum, o IPv6, prevê o aparecimento de novos serviços sobre IP (por exemplo. VoIP, streaming de vídeo em tempo real, etc). O IPv6 suporta intrinsecamente classes de serviço diferenciadas, em função das exigências e prioridades do serviço em causa.
  • Mobilidade. A mobilidade está a tornar-se um factor muito importante na sociedade de hoje em dia. O IPv6 suporta a mobilidade dos utilizadores, onde estes poderão ser contactados em qualquer rede através do seu endereço IPv6 de origem.

 Novidades nas especificações do IPv6

  • Espaço de Endereçamento. Os endereços IPv6 têm um tamanho de 128 bits.
  • Autoconfiguração de endereço. Suporte para atribuição automática de endereços numa rede IPv6, podendo ser omitido o servidor de DHCP a que estamos habituados no IPv4.
  • Endereçamento hierárquico. Simplifica as tabelas de encaminhamento dos routers da rede, diminuindo assim a carga de processamento dos mesmos.
  • Formato do cabeçalho. Totalmente remodelados em relação ao IPv4.
  • Cabeçalhos de extensão. Opção para guardar informação adicional.
  • Suporte a qualidade diferenciada. Aplicações de áudio e vídeo passam a estabelecer conexões apropriadas tendo em conta as suas exigências em termos de qualidade de serviço (QoS).
  • Capacidade de extensão. Permite adicionar novas especificações de forma simples.
  • Encriptação. Diversas extensões no IPv6 permitem, à partida, o suporte para opções de segurança como autenticação, integridade e confidencialidade dos dados.

Formato do datagrama IPv6

Um datagrama IPv6 é constituído por um cabeçalho base, ilustrado na figura que se segue, seguido de zero ou mais cabeçalhos de extensão, seguidos depois pelo bloco de dados.

Formato do cabeçalho base do datagrama IPv6:

  • Tem menos informação que o cabeçalho do IPv4. Por exemplo, o checksum será removido do cabeçalho, que nesta versão considera-se que o controle de erros das camadas inferiores é confiável.
  • O campo ‘Traffic Class’ é usado para assinalar a classe de serviço a que o pacote pertence, permitindo assim dar diferentes tratamentos a pacotes provenientes de aplicações com exigências distintas. Este campo serve de base para o funcionamento do mecanismo de qualidade de serviço (QoS) na rede.
  • O campo ‘Flow Label’ é usado com novas aplicações que necessitem de bom desempenho. Permite associar datagramas que fazem parte da comunicação entre duas aplicações. Usados para enviar datagramas ao longo de um caminho pré-definido.
  • O campo ‘Payload Length’ representa, como o nome indica, o volume de dados em bytes que pacote transporta.
  • O campo ‘Next Header’ aponta para o primeiro header de extensão. Usado para especificar o tipo de informação que está a seguir ao cabeçalho corrente.
  • O campo ‘Hop Limit’ tem o número de hops transmitidos antes de descartar o datagrama, ou seja, este campo indica o número máximo de saltos (passagem por encaminhadores) que o datagrama pode dar, antes de ser descartado, semelhante ao TTL do IPv4.

Fragmentação e determinação do percurso

No IPv6 o responsável pela fragmentação é o host que envia o datagrama, e não os routers intermédios como no caso do IPv4. No IPv6, os routers intermédios descartam os datagramas maiores que o MTU da rede. O MTU será o MTU máximo suportado pelas diferentes redes entre a origem e o destino. Para isso o host envia pacotes ICMP de varios tamanhos; quando um pacote chega ao host destino, todos os dados a serem transmitidos são fragmentados no tamanho deste pacote que alcançou o destino.
O processo de descoberta do MTU tem que ser dinâmico, porque o percurso pode ser alterado durante a transmissão dos datagramas.
No IPv6, um prefixo não fragmentável do datagrama original é copiado para cada fragmento. A informação de fragmentação é guardada num cabeçalho de extensão separado. Cada fragmento é iniciado por uma componente não fragmentável seguida de um cabeçalho do fragmento.

Múltiplos cabeçalhos

Uma das novidades do IPv6, é a possibilidade de utilização de múltiplos cabeçalhos encadeados. Estes cabeçalhos extra permitem uma maior eficiência, devido a que o tamanho do cabeçalho pode ser ajustado às necessidades. Também permite uma maior flexibilidade, porque podem ser sempre adicionados novos cabeçalhos para satisfazer novas especificações.
As especificações actuais recomendam a seguinte ordem:
2-Hop-By-Hop Options Header
3-Destination Option Header
4-Routing Header
5-Fragment Header
6-Authentication Security Payload Header
7-Destination Options Header
8-Upper-Layer Header


O endereçamento no IPv6 é de 128 bits, e inclui prefixo de rede e sufixo de host. No entanto, não existem classes de endereços, como acontece no IPv4. Assim, a fronteira do prefixo e do sufixo pode ser em qualquer posição do endereço.
Um endereço padrão IPv6 deve ser formado por um campo provider ID, subscrive ID, subnet ID e node ID. Recomenda-se que o ultimo campo tenha pelo menos 48 bits para que possa armazenar o endereço MAC.
Os endereços IPv6 são normalmente escritos como oito grupos de 4 dígitos hexadecimais. Por exemplo,


Se um grupo de vários dígitos seguidos for 0000, pode ser omitido. Por exemplo,


é o mesmo endereço IPv6 que:


Existem no IPv6 tipos especiais de endereços:

  • unicast – cada endereço corresponde a uma interface (dispositivo).
  • multicast – cada endereço corresponde a múltiplas interfaces. Enviada uma cópia para cada interface.
  • anycast – corresponde a múltiplas interfaces que partilham um prefixo comum. Um datagrama é enviado para um dos dispositivos, por exemplo, o mais próximo.

Estruturas de endereços de transição

Os endereços IPv6 podem ser compatíveis com IPv4 , podendo o primeiro conter endereços IPv4.
Para tal, os 128 bits do IPv6 ficam assim divididos:

  • campo de 80 bits colocado a ‘0’ (zero)
  • campo de 16 bits colocado a ‘0’ (zero)
  • endereço IPv4 de 32 bits

Endereços IPv6 compatíveis com IPv4:

::<endereço IPv4>

Os endereços IPv6 podem ser mapeados para IPv4 e são concebidos para routers que suportem os dois protocolos, permitindo que nós IPv4 façam um “túnel” através de uma estrutura IPv6. Ao contrário dos anteriores, estes endereços são automaticamente construídos pelos routers que suportam ambos os protocolos.
Para tal, os 128 bits do IPv6 ficam assim divididos:

  • campo de 80 bits colocado a ‘0’ (zero)
  • campo de 16 bits colocado a ‘F’
  • endereço IPv4 de 32 bits

Endereços IPv6 mapeados para IPv4:

::FFFF:<endereço IPv4>
Publicado por: heldercangula | Junho 30, 2008

How to Be a Computer Geek

Little known to most, there are many benefits to being a computer geek. In our high-tech society, being a computer guru can be one of the most high paying jobs available. By tapping into your inner geek, you can develop a most useful skill that will be sure to pay off later in life.

  1. Learn what hardware is.
  2. Learn what software is.
  3. Learn the specs (technical specifications) of your computer.
  4. Learn to navigate a computer without using the explorer window, only by using the command line. Here are some common commands:
    • cd folder (*nix/Windows) to change the directory to folder
    • ls (*nix) or dir (Windows) to list the files or folders in the current directory
    • rm file (*nix) or del file (Windows) to remove file
    • mkdir name (*nix/Windows) or md name (Windows) to make a directory with a name of name
    • cp origfile newfile (*nix) or copy origfile newfile (Windows) to copy origfile to newfile
    • Note: *nix is any Unix based system such as Linux, BSD, or MacOS X (previous versions of Mac OS are not based off of Unix)
  5. Learn to type without looking at the keyboard,
  6. Ask. If someone does something on a computer that you would like to know, ask them about it.
  7. Learning a programming language is a must-do. HTML is not considered a geeky language, nor CSS, HTML is a markup language and CSS is a presentation language. Python and PHP are excellent programming languages for beginner geeks, while Perl and C should only be learned after grasping the basic “geeky” computer and Internet concepts. If you chose to learn HTML learn XHTML.
  8. Start learning basic repair procedures. This can help you out a lot if your or someone else’s computer breaks down, which will also increase your reputation as a computer geek. You may learn the advanced methods, but that may require lessons from an actual computer geek.
  9. Work with others with their computer problems. By interacting with other PC users, you may find that they know things that you don’t and vice versa. However as a computer geek wannabe, you’ll want to know more about computer than your friends, at any given time.
  10. Help others out with their computer problems. Not only will you build a name for yourself, but it is good practice and can help you learn about situations and problems you have not encountered before.
  11. Offer to help others with their computer problems even if they claim they don’t have a problem.
  12. Learn to recognize malware(computer viruses, spyware and the other nasty stuff) before running the daily antivirus/antispyware scans.
  13. Use a restrictive firewall, that would cause normal people to cry because they don’t understand how to use it. Of course, you should know how to use it!
  14. Use an Open Source Operating System
    • Most computer geeks will use an open OS such as BSD or Linux, because it is (usually) free and allows them to do geeky stuff such as programming, running servers and using a command line interface (CLI).
  15. Know the expressionFree as in beer or free as in speech” and what it means.
  16. Use Firefox and install the NoScript addon.
  17. Use Shortcuts.
  18. Know the inner workings of the Internet.
  19. Remember to keep things simple. Skip overwhelming or overly-complicated ideas. Instead, focus on learning the knowledge and skills you may need to accomplish a big idea in the future.
  20. Learn to speak Geek!
Publicado por: heldercangula | Junho 5, 2008

Stop a Rundll Error From Wreaking Havoc on Your PC.

Hey folks my pc was always giving this error whenever i start the pc, so went through those steps and it worked , i decided to post this in my blog..enjoy.

What is a rundll error? 

Rundll.exe files are systems process directly related to your computer’s Windows Registry. All Dll files are a part of vast library that contains code and data that is shared by many programs. This helps to produce speed and memory efficiency in your operating system by reusing the same code or file to run many functions by various programs. An error occurs when program aren’t allowed to access this code.


Why do you have Rundll Errors?

Windows uses rundll files to load programs, files and applications. If the dll file is missing or corrupted, any application using that file cannot be loaded. This will produce a rundll error. The reason why the file has gone missing is often linked to spyware or a virus. This kind of malware often tries to hijack the files being shared by the rundll file. The other programs sharing the file then do not operate efficiently or wont load at all.

How to Find and Delete Rundll ErrorsSTEP 1: IDENTIFY
The first thing you must do is to identify the specific rundll process. This is not a difficult task; there is a vast online process library in which you can evaluate the validity of the process that is running. When the error dialog box opens make not of the process name. For example if the dialog pops up and shows you the dll error:

Error loading C:WINDOWSsystem32usvdgpo.dll

Often you can locate the Run Dll in the exe services. You can open up your services configuration by following instructions below:
1. Open your Start menu.
2. Click Run
3. In the command screen type:services.msc
4. This will bring up the Services Management window. If you drag the mouse to one of the services. It will give you a detailed explanation of the service in question. By right clicking the individual service.
5.Stop the “dll”service immediately.

NOTE: Sometimes the dll process can not be stopped by this method.

Stop the services to fix rundll error

You will have to open your Windows Registry File System. This is an extremely delicate process. You may want to use a good registry cleaner This will often fix the dll error in question, eliminate other errors and also speed up your computer. The registry key: HKEY_LOCAL_MACHINE> SOFTWAREMicrosoftWindowsCurrentVersion/RUN
This action will help you speed up your applications load times considerable. Here is how:
1. Click Start
2. Click Run
3. Type regedit
4. Find this registry key:
HKEY_LOCAL_MACHINE> SOFTWAREMicrosoftWindowsCurrentVersion/RUN

5. In the right section click:”rusvdgpo” = “%System%undll32.exe %System%usvdgpo.dll, [RANDOM LETTERS]”
6. Delete the value and Restart.


rundll.exe is an essential system process. However, it has a large back door vulnerability which makes it prone to malicious purposes by an attacker allowing access to your computer from remote locations, stealing passwords, Internet banking and personal data.

Trojans are usually use this method of attack to share process that invite other malware either more trojans or other forms of spyware. The best defense is to keep your security software up to date and account for the rundll processes on your computer.

Publicado por: heldercangula | Junho 3, 2008

Utilizar uma conta do Windows Live Hotmail no Outlook

Todas as contas do Windows Live Hotmail podem ser utilizadas com o Microsoft Office Outlook 2007 ou Office Outlook 2003, independentemente de se tratar de uma conta do Windows Live Hotmail gratuita ou paga. Para aceder à conta do Windows Live Hotmail com o Outlook, primeiro tem de instalar o Microsoft Office Outlook Connector for Windows Live Hotmail.

Obter informações sobre o Microsoft Office Outlook Connector

O Outlook Connector permite sincronização bidireccional de mensagens de correio electrónico, itens de calendário, contactos, tarefas e notas entre o Outlook e o Windows Live Hotmail.

 Nota   A sincronização do calendário com o Outlook é uma funcionalidade paga, cuja activação requer uma subscrição. Ao efectuar a subscrição do Windows Live Hotmail, poderá sincronizar notas e tarefas, bem como o calendário.


Se não tiver uma conta do Windows Live Hotmail, poderá inscrever-se numa nova conta ou actualizar a sua conta existente do MSN Hotmail para uma conta do Windows Live Hotmail.

Para actualizar do MSN Hotmail para o Windows Live Hotmail, clique na hiperligação Join Windows Live Hotmail quando iniciar sessão na conta. Todas as mensagens, pastas e contactos serão automaticamente apresentados na nova conta. O endereço de correio electrónico não será alterado.

Transferir e instalar o Outlook Connector

  1. Saia do Outlook.
  2. Transfira o Microsoft Office Outlook Connector.
  3. Quando lhe for pedido para abrir ou guardar o ficheiro, clique em Abrir.
  4. Quando lhe for pedido para executar o software, clique em Executar. Nota   Poderá ser apresentado um pedido de segurança, consoante o sistema operativo ou browser utilizado. Se esta caixa de diálogo for apresentada, deverá clicar na opção para continuar a instalação.
  5. Siga as instruções no ecrã para concluir a instalação.
  6. Da próxima vez que iniciar o Outlook, ser-lhe-á pedido para configurar o Outlook Connector. Introduza as seguintes informações:
    • O endereço de correio electrónico
    • A palavra-passe
    • O nome que pretende que seja apresentado na pasta A receber dos destinatários
  7. Clique em OK.




Publicado por: heldercangula | Junho 3, 2008

Microsoft Active Directory (AD), suas funções e objetos

Resumo: Este artigo busca apresentar e explicar o funcionamento básico do
Microsoft Active Directory (AD), suas funções, ferramentas e seus objetos
físicos e lógicos.
1. Informações gerais do Active Directory
O Active Directory que neste artigo chamaremos de AD, surgiu junto com o Sistema
operacional Microsoft Windows Server 2000, ele foi desenvolvido de acordo com o
protocolo LDAP e com certeza é um dos principais motivos de sucesso do Windows
2000 Server e Windows 2003 Server.
1.1 Oquê é o AD?
Podemos dizer que o AD é um serviço de diretório que identifica todos os recursos
disponíveis de um ambiente de rede e fornece informações detalhadas sobre objetos
deste ambiente, tais objetos podem ser computadores, usuários, servidores,
impressoras, etc.
1.2 Qual sua finalidade?
Com o AD, os administradores de rede podem gerenciar de forma mais simples e
eficaz os objetos de seu ambiente. E os usuários deste ambiente de rede podem
utilizar e encontrar rapidamente estes objetos.

2. Principais recursos do AD?
» Autenticação centralizada: Os usuários cadastrados no AD se autentificam em
todos os computadores da empresa, e é a partir desta autentificação que é aplicado a
permissão de leitura, modificação e etc. Tais permissões são aplicadas de forma
imperceptível ao usuário.
» Nível de segurança controlado: Tratasse de um centralizador de políticas de
segurança, com isso é garantido que toda a rede seguirá as políticas de segurança pré
definidas. Um exemplo: A quantidade mínima de caracteres para uma senha.
» Capacidade de integração com sistemas: É possível integrar o AD com sistemas
de gestão ou outros aplicativos, fazendo com que ao invés de o sistema ter o seu
próprio banco de usuários e senhas, ele use os usuários do AD. Facilitando assim o
dia – a –dia do usuário.

» Administração centralizada das estações: Com as ferramentas que o AD nos
oferece é possível que as estações de trabalho sejam administradas por ele. Por
exemplo, para o setor de engenharia a unidade de CDRW ser bloqueada, ou seja, é
possível personalizar os computadores de acordo com a necessidade ou segurança
necessária a cada setor.

» Tecnologia enxergando a organização da empresa. Com o AD é possível
visualizar a organização da empresa, pois é possível adicionar no AD, a empresa
matriz e suas filiais, por exemplo. Tal visualização nos leva a uma administração
mais simples da rede. Na figura1 vemos todas as plantas da empresa JCI, de diversos
segmentos, que se localizam na América do Sul (SA).

Publicado por: heldercangula | Junho 3, 2008

Networking Basics: Part 2 – Routers

In the first part of this article series, I talked about some basic networking hardware such as hubs and switches. In this article, I want to continue the discussion of networking hardware by talking about one of the most important networking components; routers.

Even if you are new to networking, you have probably heard of routers. Broadband Internet connections, such as those utilizing a cable modem or a DSL modem, almost always require a router. A router’s job isn’t to provide Internet connectivity though. A router’s job is to move packets of data from one network to another. There are actually many different types of routers ranging from simple, inexpensive routers used for home Internet connectivity to the insanely expensive routers used by giant corporations. Regardless of a router’s cost or complexity, routers all work on the same basic principles.

That being the case, I’m going to focus my discussion around simple, low budget routers that are typically used to connect a PC to a broadband Internet connection. My reason for doing so is that this article series is intended for beginners. In my opinion, it will be a lot easier to teach you the basics if I am referencing something that is at least somewhat familiar to most people, and that is not as complicated as many of the routers used within huge corporations. Besides, the routers used in corporations work on the same basic principles as the routers that I will be discussing in this article. If you are wanting a greater level of knowledge though, don’t worry. I will talk about the science of routing in a whole lot more detail later in this article series.

As I explained earlier, a router’s job is to move packets of data from one network to another. This definition might seem strange in the context of a PC that’s connected to a broadband Internet connection. If you stop and think about it, the Internet is a network (actually it’s a collection of networks, but that’s beside the point).

So if a router’s job is to move traffic between two networks, and the Internet is one of those networks, where is the other one? In this particular case, the PC that is connected to the router is actually configured as a very simple network.

To get a better idea of what I am talking about, take a look at the pictures shown in Figures A and B. Figure A shows the front of a 3COM broadband router, while Figure B shows the back view of the same router.

Figure A: This is the front view of a 3COM broadband router

Figure B: A broadband Internet router contains a set of RJ-45 ports just like a hub or switch

As you can see in the figures, there is nothing especially remarkable about the front view of the router. I wanted to include this view anyway though, so that those of you who are unfamiliar with routers can see what a router looks like. Figure B is much more interesting. 

If you look at Figure B, you’ll see that there are three sets of ports on the back of the router. The port on the far left is where the power supply connects to the router. The middle port is an RJ-45 port used to connect to the remote network. In this particular case, this router is intended to provide Internet connectivity. As such, this middle port would typically be used to connect the router to a cable modem or to a DSL modem. The modem in turn would provide the actual connectivity to the Internet.

If you look at the set of ports on the far right, you’ll see that there are four RJ-45 ports. If you think back to the first part of this article series, you’ll recall that hubs and switches also contained large groups of RJ-45 ports. In the case of a hub or switch, the RJ-45 ports are used to provide connectivity to the computers on the network.

These ports work the exact same way on this router. This particular router has a four port switch built in. Remember earlier when I said that a router’s job was to move packets between one network and another? I explained that in the case of a broadband router, the Internet represents one network, and the PC represents the second network. The reason why a single computer can represent an entire network is because the router does not treat the PC as a standalone device. Routers treat the PC as a node on a network. As you can see from the photo in Figure B, this particular router could actually accommodate a network of four PCs. It’s just that most home users who use this type of configuration only plug one PC into the router. Therefore a more precise explanation would be that this type of network routes packets of data between a small network (even if that network only consists of a single computer) to the Internet (which it treats as a second network).

The Routing Process

Now that I’ve talked a little bit about what a router is and what it does, I want to talk about the routing process. In order to understand how routing works, you have to understand a little bit about how the TCP/IP protocol works.

Every device connected to a TCP/IP network has a unique IP address bound to its network interface. The IP address consists of a series of four numbers separated by periods. For example, a typical IP address looks something like this:

The best analogy I can think of to describe an IP address is to compare it to a street address. A street address consists of a number and a street name. The number identifies the specific building on the street. An IP address works kind of the same way. The address is broken into the network number and a device number. If you were to compare an IP address to a Street address, then think of the network number as being like a street name, and at the device number as being like a house number. The network number identifies which network the device is on, and the device number gives the device an identity on that network.

So how do you know where the network number ends and the device number begins? This is the job of the subnet mask. A subnet mask tells the computer where the network number portion of an IP address stops, and where the device number starts. Subnetting can be complicated, and I will cover in detail in a separate article. For now, let’s keep it simple and look at a very basic subnet mask.

A subnet mask looks a lot like an IP address in that it follows the format of having four numbers separated by periods. A typical subnet mask looks like this:

In this particular example, the first three numbers (called octets) are each 255, and the last number 0. The number 255 indicates that all of the bits in the corresponding position in the IP address are a part of the network number. The number zero indicates that none of the bits in the corresponding position in the IP address are a part of the network number, and therefore they all belong to the device number.

I know this probably sounds a little bit confusing, so consider this example. Imagine that you had a PC with an IP address of and a subnet mask of In this particular case, the first three octets of the subnet mask are all 255. This means that the first three octets of the IP address all belong to the network number. Therefore, the network number portion of this IP address is 192.168.1.x.

The reason why this is important to know is because a router’s job is to move packets of data from one network to another. All of the devices on a network (or on a network segment to be more precise) share a common network number. For example, if 192.168.1.x was the network number associated with computers attached to the router shown in Figure B, then the IP addresses for four individual computers might be:


As you can see, each computer on the local network shares the same network number, but has a different device number. As you may know, whenever a computer needs to communicate with another computer on a network, it does so by referring to the other computer’s IP address. For example, in this particular case the computer with the address of could easily send a packet of data to the computer with the address of, because both computers are a part of the same physical network.

Things work a bit differently if a computer needs to access a computer on another network. Since I am focusing this particular discussion on small broadband routers that are designed to provide Internet connectivity, let’s pretend that one of the users on the local network wanted to visit the Web site. A Web site is hosted by a server. Like any other computer, a Web server has a unique IP address. The IP address for this particular Web site is

You can easily look at this IP address and tell that it does not belong to the 192.168.1.x network. That being the case, the computer that’s trying to reach the Web site can’t just send the packet out along the local network, because the Web server isn’t a part of the local network. Instead, the computer that needs to send the packet looks at its default gateway address.

The default gateway is a part of a computer’s TCP/IP configuration. It is basically a way of telling a computer that if it does not know where to send a packet, then send it to the specified default gateway address. The default gateway’s address would be the router’s IP address. In this case, the router’s IP address would probably be

Notice that the router’s IP address shares the same network number as the other computers on the local network. It has to so that it can be accessible to those computers. Actually, a router has at least two IP addresses. One of those addresses uses the same network number as your local network. The router’s other IP address is assigned by your ISP. This IP address uses the same network number as the ISPs network. The router’s job is therefore to move packets from your local network onto the ISPs network. Your ISP has routers of its own that work in exactly the same way, but that route packets to other parts of the Internet.


As you can see, a router is a vital network component. Without routers, connectivity between networks (such as the Internet) would be impossible. In Part 3 of this article series, I will discuss the TCP/IP protocol in more detail.

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