Rangkuman CCNA Discovery 2 - Chapter 1

The Internet is a worldwide, publicly accessible network of networks. It enables individuals and businesses alike .In the beginning, the Internet was used strictly for scientific, educational, and military research. The Internet has grown rapidly, and is now global. New technologies are continuously being developed that make the Internet easier and more attractive to use.

                Networking and Internet standards ensure that all devices connecting to the network use the same set of rules. When a new standard is proposed, each stage of the development and approval process is recorded in a numbered Request for Comments (RFC) document so that the evolution of the standard is tracked. Because these organizations create and maintain standards, millions of individuals are able to connect to the Internet using a variety of devices, including personal computers, mobile phones, handheld personal digital assistants (PDAs), MP3 players, and even televisions.

                an individual or business uses to connect to the Internet, the device must connect through an Internet service provider (ISP). An ISP is a company or organization through which a subscriber obtains Internet access.  

In addition to offering connection to the Internet, an ISP can offer other services to subscribers, including:

1 1)      Equipment co-location - A business may opt to have some or all internal network equipment physically located on the ISP premises.

2 2)      Web hosting - The ISP provides the server and application software for storing web pages and web content for the business website.

3 3)      FTP - The ISP provides the server and application software for the FTP site of a business.

4 4)      Applications and media hosting - The ISP provides the server and software to allow a business to provide streaming media such as music, video, or applications such as online databases.

5 5)      Voice over IP - A business can save on long distance telephone charges, especially for internal calls between geographically distant offices, by using Voice over IP (VoIP).

6 6)      Technical support - Many businesses do not have the in-house technical expertise to manage large internal networks. Some ISPs provide technical support and consulting services for an additional fee.

77 )      Point of Presence (POP) - A business has the option of connecting to the ISP through POP, using a variety of access technologies.

To gain access to the Internet, it is first necessary to have a connection to an ISP. ISPs offer various 

connection options. 

The main connection methods used by home and small business users are:

1 1)      Dialup access -Dialup access is an inexpensive option that uses any phone line and a modem. Dialup is the slowest connection option.

2 2)      DSL( Digital subscriber line)- The DSL connection is faster  better than dialup and DSL, is more expensive than dialup. This connection option uses a special high-speed modem that separates the DSL signal from the telephone signal and provides an Ethernet connection to a host computer or LAN.

3 3)      Cable modem- A cable modem is a connection option offered by cable television service providers. The Internet signal is carried on the same coaxial cable that delivers cable television to homes and businesses. 

4 4)      Satellite-  Satellite connection is an option offered by satellite service providers. The user's computer connects through Ethernet to a satellite modem that transmits radio signals to the nearest Point of Presence, or POP, within the satellite network.

Bandwidth is measured in bits per second (bps). Higher bandwidth speeds are measured in kilobits per second (kbps), megabits per second (Mbps), or gigabits per second (Gbps).

There are three main types of high-bandwidth connection options that are used by businesses:

1 1)      T1 connections transmit data up to 1.544 Mbps. T1 connections are symmetrical, meaning that the upload bandwidth is the same as the download bandwidth. E1 adalah standar Eropa yang mentransmisikan data pada 2,048 Mbps.

2 2)      Koneksi T3 transmit data up to 45 Mbps. E3 adalah standar Eropa yang mentransmisikan data pada 34,368 Mbps.

3 3)      Metro Ethernet transmit data up to GBps. Metro Ethernet allows the transfer of large amounts of data faster and less expensively than other high-bandwidth connection options.

After the type of connection is established, it is necessary to connect to the ISP to get access to the Internet. Individual computers and business networks connect to the ISP at the POP. POPs are located at the edge of the ISP network and serve a particular geographical region. They provide a local point of connection and authentication (password control) for multiple end users. An ISP may have many POPs, depending on the size of the POP and the area that it services.

The Internet has a hierarchical structure. At the top of this hierarchy are the ISP organizations. The ISP POPs connect to an Internet Exchange Point (IXP). In some countries, this is called a Network Access Point (NAP)

ISPs are classified into different tiers according to how they access the Internet backbone:

1 1)      Tier 1 ISPs  are the top of the hierarchy. Tier 1 ISPs are huge organizations that connect directly with each other through private peering, physically joining their individual network backbones together to create the global Internet backbone.

2 2)      Tier 2 ISPs are the next tier in terms of backbone access. Tier 2 ISPs can also be very large, even extending across several countries, but very few have networks that span entire continents or between continents.

3 3)      Tier 3 ISPs are the farthest away from the backbone. Tier 3 ISPs are generally found in major cities and provide customers local access to the Internet. Tier 3 ISPs pay Tier 1 and 2 ISPs for access to the global Internet and Internet services.

The ping command tests the accessibility of a specific IP address. The ping command sends an ICMP (Internet Control Message Protocol) echo request packet to the destination address and then waits for an echo reply packet to return from that host. ICMP is an Internet protocol that is used to verify communications.

 

Utilitas traceroute menampilkan jalur bahwa suatu paket mengambil dari sumber ke host tujuan. Setiap router bahwa paket melewati disebut hop sebuah. If a problem occurs, use the output of the traceroute utility to help determine where a packet was lost or delayed.  The Windows tracert utility works the same way. There are also a number of visual traceroute programs that provide a graphical display of the route that a packet takes.

An ISP requires a variety of devices to accept input from end users and provide services. To participate in a transport network, the ISP must be able to connect to other ISPs. An ISP must also be able to handle large volumes of traffic.

Some of the devices required to provide services include:

1 1)      Access devices that enable end users to connect to the ISP, such as a DSL Access Multiplexer (DSLAM) for DSL connections, a Cable Modem Termination System (CMTS) for cable connections, modems for dialup connections, or wireless bridging equipment for wireless access.

2 2)      Border gateway routers to enable the ISP to connect and transfer data to other ISPs, IXPs, or large business enterprise customers.

3 3)      Servers for such things as email, network address assignment, web space, FTP hosting, and multimedia hosting.

4 4)      High capacity air conditioning units to maintain controlled temperatures.

the increased traffic may overload the network, causing router errors, lost packets, and excessive delays. In an overloaded network, subscribers can wait for minutes for a web page to load, or may even lose network connection.

                Scalability is the capacity of a network to allow for future change and growth. Scalable networks can expand quickly to support new users and applications without affecting the performance of the service being delivered to existing users.

The most scalable devices are those that are modular and provide expansion slots for adding modules. Different modules can have different numbers of ports.

ISP organizations consist of many teams and departments which are responsible for ensuring that the network operates smoothly and that the services are available.

Some of the Teams required to provide services include:

1 1)      One-Site Installations team

2 2)      Planning and Provisioning team

3 3)      Network Operations Center  (NOC) team

4 4)      Customer service order entry

5 5)      Help Desk Technical Support.

Each of the network support service teams have their own roles and responsibilities:

1 1)      Customer Service receives the order from the customer and ensures that the specified requirements of the customer are accurately entered into the order tracking database.

2 2)      Planning and Provisioning determines whether the new customer has existing network hardware and circuits and if new circuits need to be installed.

3 3)      The On-site Installation is advised of which circuits and equipment to use and then installs them at the customer site.

4 4)      The Network Operations Center (NOC) monitors and tests the new connection and ensures that it is performing properly.

5 5)      The Help Desk is notified by the NOC when the circuit is ready for operation and then contacts the customer to guide them through the process of setting up passwords and other necessary account information.