Network Interface Card

Network Card (UK: network interface card or NIC also abbreviated network card) is a card that serves as a bridge from your computer to a computer network. NIC Type outstanding, divided into two types, namely the physical NIC, and NIC that is logical. Examples of a physical NIC is the NIC Ethernet, Token Ring, and others, while the NIC that is logical is the loopback adapter and Dial-up Adapter. Also referred to as the Network Adapter. Each type of NIC is numbered addresses called MAC address, which can be either static or can be modified by users.


Physical NIC
Generally in the form of a physical NIC cards that can be plugged into a slot in the computer's motherboard, which may be a card with ISA bus, PCI bus, EISA bus, MCA bus, or PCI Express bus. Besides the form of cards that plugged into the motherboard, the physical NIC can also be an external card that a card with a USB bus, PCMCIA, serial bus, parallel bus or Express Card, thereby increasing the mobility (for mobile users).
Physical NIC card is divided into two types, namely:

•     NIC card with a specific network medium (Media-specific NIC): NIC card differentiating into several types based on the network media is used. Examples are Ethernet NIC, which can be a Twisted-Pair (UTP or STP), thinnet, or Thicknet, or even wirelessly (Wireless Ethernet).
•     NIC card with a specific network architecture (architecture-specific NIC): NIC card differentiating into several types, according to the network architecture is used. Examples are Ethernet, Token Ring, and FDDI (Fiber Distributed Data Interface), all of which use a different NIC. Ethernet NIC card can be either Ethernet 10 megabits / sec, 100 megabits / second, 1 gigabit / second or 10 Gigabit / sec.

NIC task is to convert parallel data flow within the computer bus into serial data form that can be transmitted over the network media. Media that is commonly used, among other UTP cable Enhanced Category 5 or Category 5 (Cat5e), fiber-optic cable, or radio (if indeed without cable).
Computers can communicate with the NIC by using several methods, namely I / O is mapped into memory, Direct Memory Access (DMA), or memory to be used together. A parallel data stream is sent to the NIC card in advance and stored in memory in the card before it is bundled into many different frames, before it finally can be transmitted through the network media. The process of making this frame, will add a header and trailer to the data about to be sent, containing the address, signaling, or error-checking information. The frames will then be converted into electronic pulses (voltage, especially for copper cables), pulses of light modulated (especially for fiber-optic cables), or microwave (if using radio / wireless networks).
NIC that is in the receiver to process signals obtained in the form upside down, and turn signals into the bit stream (for a frame network) and convert these bits into parallel data flow in the recipient computer bus. Some of these functions can be directly owned by the NIC, installed in the firmware, or in the form of software that is installed in the operating system.


Logical NIC
Logical NIC  is a type that does not exist physically and use the software fully installed on the operating system and work as if he is a NIC. Examples of logical NIC device is the loopback adapter (in the Windows operating system, must be installed manually or in the UNIX family of operating systems, installed by default, with the lo interface name) and Dial-up adapter (which makes the modem as a networking tool in the operating system Windows). Logical NIC card is made ​​by using emulation techniques.