wide area network (WAN)

wide area network (WAN) is a telecommunication network that covers a broad area (i.e., any network that links across metropolitan, regional, or national boundaries). Business and government entities utilize WANs to relay data among employees, clients, buyers, and suppliers from various geographical locations. In essence this mode of telecommunication allows a business to effectively carry out its daily function regardless of location.

This is in contrast with personal area networks (PANs), local area networks (LANs), campus area networks (CANs), or metropolitan area networks (MANs) which are usually limited to a room, building, campus or specific metropolitan area (e.g., a city) respectively.

LAN (local area network)

Local area network is a computer network whose network covers only a small area, such as campus computer networks, buildings, offices, in homes, schools or smaller. Today, most LAN technology based on IEEE 802.3 Ethernet switch using the device, which has a data transfer speed 10, 100, or 1000 Mbit / s. In addition to Ethernet technology, the current 802.11b technology (or so-called Wi-Fi) is also often used to form the LAN. Places that provide LAN connectivity with Wi-Fi technology called hotspots.

On a LAN, each node or computer has its own computing power, in contrast to the concept of terminal dump. Each computer can also access resources on the LAN in accordance with the perm

Network address translation (NAT)

Network address translation is a method to connect more than one computer to the Internet network by using a single IP address. Much use of this method due to the limited availability of IP addresses, the need for safety (security), and the ease and flexibility in network administration.

IP addresses

Currently, the widely used IP protocol is IP version 4 (IPv4). With a length of 4-byte address means that there are 2 to the power 32 = 4,294,967,296 available IP addresses. This amount is theoretically the number of computers that can directly connect to the internet. Because of this limitation of most ISPs (Internet Service Provider) will only allocate one address for one user and this address is dynamic, in the sense of a given IP address will be different each time a user to connect to the internet. This will make it difficult for businesses to lower middle class. On the one hand they need more computers are connected to the internet, but on the other hand only one available IP address, which means there is only one computer that can connect to the internet. This can be overcome with the NAT method. With a NAT gateway that runs on one computer, one IP address can be divided into several other computers and they can connect to the internet simultaneously

Routing static and Routing dynamic

Routing Static

a routing table creation manually. Static routing is useful for simple networks where routers only use a few pieces only and is useful for saving bandwidth usage. Manually point is if my friend as a network administrator, type in certain commands to create a static IP routing as an example, suppose I type the following command:
router (config) # ip route network_destination_id subnet_mask default_gateway [administrative_distance]
The following description of the command that I created above:

network_destination_id is the network address of the destination
subnet_mask is the subnet mask of the destination network.
default_gateway is the gateway IP address, router address is usually directly related.
administrative_distance is the value 0-255 given to routing. Increase low value given the high increase its usefulness. If the value is not given then a default value will be used. The default value for directly connected (C) = 0 and statically connected (S) = 1.

subnetting/subnet mask

The subnet mask is the term information technology in the English language that refers to the 32 bit binary number that is used to distinguish the network ID with the host ID, showing the location of a host, whether located on a local network or external networks.

RFC 950 defines the use of a subnet mask which is also called as an address mask as a 32-bit value that is used to distinguish the network ID of the host ID in an IP address. The bits of the subnet mask is defined, are as follows:

- All bits are intended to be used by the network ID is set to a value of 1.
- All bits are intended to be used by the host ID is set to a value of 0.

IP ADDRESS

IP Address is the address given to the network and network equipment that uses the protocol TCP / IP. IP Address consists of 32-bit binary numbers which can be written as four decimal numbers separated by a dot such as 192.16.10.1. Therefore, the IP protocol is the most widely used protocol for forwarding (routing) information in a computer network with one another, then we must truly understand that IP address. But understanding the IP addresses and subnetting often somewhat confusing users. Therefore, in here will be described step by step the concept of an IP address with the hope that you can understand how to use it well. IP Address consists of two parts, namely the network ID and host ID, which determines the address of the network ID and host ID determines the network of network equipment. Therefore, the IP address to give the full address of a network equipment and network address where the equipment is located. This is the same proverbial with the provision of residential address of the house where we are.

Implementation 802 xx

The IEEE 802 Standard comprises a family of networking standards that cover the physical layer specifications of technologies from Ethernet to wireless. IEEE 802 is subdivided into 22 parts that cover the physical and data-link aspects of networking. The better known specifications (bold in table below) include 802.3 Ethernet, 802.11 Wi-Fi, 802.15 Bluetooth/ZigBee, and 802.16.

"Grandaddy" of the 802 specifications. Provides asynchronous networking using "carrier sense, multiple access with collision detect" (CSMA/CD) over coax, twisted-pair copper, and fiber media. Current speeds range from 10 Mbps to 10 Gbps.

Transmission media

 What is Transmission media

Transmission media is a media that connects between the sender and receiver of information (data), because of the distance, then the first data is converted into code / cue, and this signals to be manipulated in various ways to be converted back into data.
 

Usefulness of transmission media

Transmission mediaused in some electronic equipment to connect between the sender and receiver to be able to exchange data. Some electronic devices, such as telephones, computers, television, and radio transmission media need to be able to receive data. As in the receiver, the transmission mediaused to connect two phones are wired. Every electronic device has a transmission mediawhich vary in data delivery.

 Characteristics of transmission media
Characteristics of transmission media is dependent on:
- Types of electronic devices
- Data used by electronic devices such
- The level of effectiveness in the delivery of data
- Size of data transmitted
This type of transmission media
Guided Transmission Media
Guided transmission media or guided transmission mediais a network that uses a cable system.

Twisted Pair Cable
Twisted pair cable or twisted pair cable consists of two conductors are coupled with the aim to reduce or eliminate interference from the outside like lektromagnetik electromagnetic radiation from unshielded twisted-pair cable (UTP), and crosstalk that occurs between adjacent wires. There are two kinds of Twisted Pair Cable, the STP and UTP cable. STP cable (Shielded Twisted Pair) is one type of cable used in computer networks. This cable contains two pairs of wires (four wires) of each twisted pair. STP cable is more resistant to interference disebebkan wires are bent position. At STP cable attenuation to increase at high frequencies giving rise to crosstalk and noise signals. UTP (Unshielded Twisted Pair) is widely used in computer network installation. This cable contains four pairs of twisted-pair wires each (twisted). These cables are not equipped with protective (unshilded). UTP cable is easy to install, small size, and price is cheaper than other types of media. UTP cables are particularly vulnerable to the effects of electrical interference from the surrounding media.

NETWORK APPLICATION

Networking Software Applications and Tools
Network software applications using the Internet or other network infrastructure hardware to perform useful functions.

• Macintosh Network
• Windows Firewall Software
• Network Operating System
• Gaming Network
• FTP Client and Server
• Network Ping (6)
• Microsoft Internet Explorer
• Linux Networking (6)
• Network Programming

INTERNET CONNECTIVITY APPLICATIONS

• Web-server applications (JAVA / PERL-CGI)
• Download file
• Automatic data distribution
• Monitoring and control
• Both real-time and store-and-forward data available architectures
• Connectivity: Wi-Fi 802.11a / b, 2-way pager / cell network, low-cost radio, dial-up services

About the OSI and TCP / IP

OSI (Open Systems Interconnection)

OSI is a conceptual model consisting of seven layers, each layer has a different function. OSI was developed by the international agency that is ISO (International Organization for Standardization) in 1977.

The function of each layer of the OSI:

     1. Physical Layer

Physical Layer is the layer that very simple, relating to electrical (and optical) connections between devices. This layer Serves to define the network transmission media, signaling method, synchronization bits, network architecture (such as Ethernet or Token Ring), network topology and pengabelan. In addition, this level also defines how the Network Interface Card (NIC) can interact with the media cable or radio.

2. Data-link Layer

Data link layer is responsible at the end of the package binary data derived from a higher level into discrete packets before the physical layer. Will send frames (block of data) via a network. Protocol on the data-link layer is Ethernet (802.2 & 802.3), Tokenbus (802.4) and Tokenring (802.5).

3.      Network Layer

Network layer provides routing functionality so that packets can be sent out from the local network segment to a destination that is on a network other.

Some network layer functions:
- Divide the binary data stream into discrete packets with a certain length
- Detect Error
- Fix error with resend the corrupted packet
- Controlling the flow

4. Transport Layer
Transport layer is the center of the fashion-OSI. Serves to break down data into packets of data and provide the serial number of the packages that can be rearranged on the side of the goal as it arrives.

5. Session Layer
This layer coordinates communication between the layer entities they represent. Serves to define how the connection can be established, maintained, or destroyed. In addition, at this level also performed name resolution. Some of the protocol at this layer: NETBIOS: a session interfaces and protocols, developed by IBM, which provides service to the presentation layer and application layer. NETBEUI, (NETBIOS Extended User Interface), a development of NETBIOS used in micro ** oft networking products, such as Windows NT and LAN Manager. ADSP (AppleTalk Data Stream Protocol). PAP (Printer Access Protocol), which is found on a Postscript printer to access the AppleTalk network.

Differences of windows server and linux server

WINDOWS SERVER HOST ING

Window, similar to your personal computer, Microsoft's operating system is commercially owned. Its main benefit is that it can also run Microsoft software such as Access and MS SQL databases.

WINDOWS SECURITY:

Because it is a commercial operating system, it could take a little longer in fixing some security issues (often with the release of the security package) while they usually must be made ​​available through Microsoft.

LINUX SERVER HOSTING

Linux is an open source system that freely circulating, which makes it very cost-effective for the host to provide, maintain, and operate. It also has a very strong position for both speed and stability. It is accepted that the best part of the site that hosts basically the Linux operating system.

 LINUX SECURITY:

Although Linux and Windows can try to deal with both hacking, arguing that Linux is open source, patches to close security holes are implemented very quickly because so many people contribute to making it better every day.

The meaning of hierarchy in the tree topology

Network Topology Tree (Tree) network topology is referred to as a multilevel network topology. This topology is typically used for interconnection between the central with a different hierarchy. For the lower hierarchy depicted in locations with low and growing up had a higher hierarchy. This type of network topology suitable for use on a computer network system.

In tree networks, there are several levels of nodes (node​​). Central or higher level node, another node can set a lower level. Data sent to the central node first. For example to move from computer to the komputer node node-3-7 as well as in the figure, the data must pass through node-3, 5 and node-6 before ending at the node-7.

The excellence of tree network  model like this is, can the formation of a group that required at all times. For example, companies can form a group consisting of terminal accounts, as well as in the other group formed for the sale terminals. The weakness is, if the node that is higher then does not work, then the other group who are below it eventually also became ineffective. The workings of a tree network is relatively slow.

the differences in lan, man, and wan

Ø   Local Area Network (LAN), 

Is a privately owned network within a building or campus-sized to several kilometers.

LAN  often used to connect personal computers and workstations in a corporate office or factories in order to use shared resources (resouce, such as printers) and exchange information.

Ø    Metropolitan Area Network (MAN)
 

      basically a LAN version of the larger and usually use the same technology to the LAN. MAN can include corporate offices are located adjacent or also a town and can be used for private purposes (private) or public. MAN capable of supporting data and voice, even may be associated with cable television networks.

Ø   Wide Area Network (WAN)
 the range covers a wide geographical area, often covering a country or even continent. WAN consists of a collection of machines that aim to run the programs (applications) user.

What sets it apart :
1. a distance

2. Speed ​​data transfer

for Ex: LAN has a limited area but has a 2 KM Sampa 2 MBPS transfer rate, while the WAN has a range up to thousands "of KM but possessed transfer rate up to 64kbps