Application Programming Interface (API)

Application Programming Interface (API)

Application layer

 

·         Combines the features of the top three layers of the OSI model. It consists of the process that applications use to initiate,control, and disconnects from a remote system.

 

Application Programming Interface (API)

 

·         Share functions, subroutines, and libraries that allow programs on a machine to communicate with the OS and other programs.

 

Broadcast

 

·         a frame or packet address to all machines, almost limited to a broadcast domain

 

Broadcast address

 

·         The address a NIC attaches to a frame when it wants every other NIC on the network to read it. In TCP/IP, the general broadcast address is 255.255.255.255. In Ethernet, the broadcast MAC address is FF-FF-FF-FF-FF-FF

 

Cyclic redundancy check (CRC)

 

·         A mathematical method used to check for errors in long streams of transmitted data with high accuracy.

 

Data Link layer

 

·         Identifies devices on the physical layer. MAC addresses are part of the Data Link layer. Bridges operate at the Data Link layer.

 

Datagram

 

·         A connectionless transfer unit created with User Datagram Protocol designed for quick transfers over a packet-switched networ

 

de-encapsilation

 

·         The process of stripping all the extra header information from a packet as the data moves up a protocol stack.

 

EUI-48

 

·         The IEEE term for the 48-bit MAC address to a network interface. The first 24 bit of the EUI-48 are assigned by the IEEE as the organizationally unique identifier (OUI)

 

Frame

 

·         A defined series of binary data that is the basic container for a discrete amount of data moving across a network. Frames are created at Layer 2 of the OSI model.

 

frame check sequence (FCS)

 

·         A sequence of bits placed in a frame that is used to check the primary data for errors.

 

Internet layer

 

·         Same as the OSI's Network layer. Any part of the network that deals with pure IP packets-getting a packet to its destination-is on the Internet layer.

 

Internet Protocol (IP)

 

·         The Internet standard protocol that handles the logical naming for the TCP/IP protocol using IP addresses.

 

IP address

 

·         The numeric address of computer connected to a TCP/IP network, such as the Internet. IPv4 addresses are 32 bits long, written as four octets of 8-bit binary. IPv6 addresses are 128 bits long, written as eight sets of four hexadecimal characters. IP addresses must be matched with a valid subset mask, which identifies the part of the IP address that is the network ID and the part that is the host ID.

 

Link layer

 

·         (Network Interface layer) is similar to OSI's Data Link and Physical layer. The Link layer consists of any part of the network that deals with frames.

 

Logical address

 

·         A programming network address, unlike a physical address that is burned into ROM.

 

logical addressing

 

·         As opposed to physical addressing, the process of assigning organized blocks of logically associated network addresses to create smaller manageable networks called subnets. IP addresses are one example of logical addressing

 

Logical Link Control (LLC)

 

·         The aspect of the NIC that talks to the operating system, places outbound data coming "down" from the upper layers of software into frames, and creates the FCS on each frame. the LLC also deals with incoming frames by processing those addressed to the NIC and erasing ones addressed to other machines on the network.

 

MAC-48

 

·         The unique 48-bit address assigned to a network interface card. This is also known as the MAC address or the EUI-48

 

MAC address

 

·         Unique 48-bit address assigned to each network card. IEEE assigns blocks of possible addresses to various NIC manufactures to help ensure that each address is unique. The Data Link layer of the OSI seven -layer model uses MAC addresses for locating machines.

 

Media Access Control (MAC)

 

·         The part of a NIC that remembers the NIC's own MAC address and attaches that address to outgoing frames.

 

 

media access control address

 

·         Unique 48-bit address assigned to each network card. IEEE assigns blocks of possible addresses to various NIC manufactures to help ensure that each address is unique. The Data Link layer of the OSI seven -layer model uses MAC addresses for locating machines.

 

network interface card (NIC)

 

·         traditionally an expansion card that enables a PC to link physically to a network. Modern computers now use built-in NICs, no longer requiring physical cards but the term "NIC" is still very common.

 

 

Network Interface layer

 

·         The TCP/IP model lumps together the OSI mo

 

Network layer

 

·         Layer 3 of the OSI seven layer model

 

network protocol

 

·         Special software that exists in every network-capable operating system thst acts to create unique identifiers for each system. It also creates a set of communion rules for issues like how to handle data chopped up into multiple packets and how to deal with routers. TCP/IP is the dominant network protocol today.

 

Open Systems Interconnection (OSI) seven-layer model

 

·         An architecture model based on the OSI protocol suite, which defines and standardizes the flow of data between computers.

 

Organizationally Unique Identifier (OUI)

 

·         The first 24 bits of a MAC address, assigned to the NIC manufacturer by the IEEE.

 

Packet

 

·         Basic component of communion over a network. A group of bits fixed maximum size and well-defined format that is switched and transmitted as a complete whole through a network. It contains source and destination address, data, and control information. See also Frame.

 

Payload

 

·         The primary data that is sent from a source network device to a destination network advice tgft

 

physical address

 

·         An address burned into a ROM chip on a NIC. A MAC address is an example of a physical address

 

 

Physical layer

 

·         Defines hardware connections and turns )binary into physical pulses (electrical light). Repeaters and hubs operate at the physical layer.

 

Presentation layer

 

·         Manages data encryption, hides the differences among various types of computer systems.

 

Protocol

 

·         An agreement that governs the procedures used to exchange information between cooperating entities; usually inculcates how much information is to be sent, how often it is sent, how to recover from translation errors, and who is to receive the information.

 

Router

 

·         A device that connects separate networks and forwards a packet from one network to another based only on the network address for the protocol being used. For example, on IP router looks at the IP network number. Routers operate at Layer 3 (Network) of the OSI seven-layer model.

 

Segment

 

·         The bus cable to which computers on an Ethernet network connection.

 

Session layer

 

·         Manages connections between machines. NetBIOS and Sockets operate at the Session layer

 

Session software

 

·         Handel the process of differentiating among various types of connections on a PC.

 

Subnet

 

·         Each independent network in a TCP/IP internet

 

Switch

 

·         A Layer 2 (Data Link) multiport device that filters and forwards frames based on the MAC addresses.

 

TCP segment

 

·         The connection-oriented payload of an IP packet. A TCP segment works on the transport layer.

 

Transmission Control Protocol (TCP)

 

·         Part of the TCP/IP protocol suite, operates at layer 4 (Transport) of the OSI seven-layer model. TCP is a connection-oriented protocol.

 

Transmission Control Protocol/ Internet Protocol (TCP/IP) model

 

·         A set of communication protocols developed by the U.S. Department of Defense that enables dissimilar computers to share information over a network.

 

Transport layer

 

·         Combines the features of OSI's Transport and Session layers. It is concerned with the assembly and disassembly of data, as well as connection-oriented and connectionsless communication.

 

UDP datagram

 

·         A connectionless networking container used in UDP communication

 

Unshielded twisted pair (UTP)

 

·         A popular cabling for telephone and network composed of pairs and wires twisted around each other at specific intervals. The twist serve to reduce interference (Crosstalk). The more twist, the less interference. The cable has no metallic shielding to protect the wires from external interference, unlike its cousin, STP. 10BaseT uses UTP, as do many other networking technologies =. UTP is available in a variety of grades, called categories, as defined in the following:

Category 1 UTP: Regular analog phone lines, not used for data communications.

Category 2 UTP: Supports speeds up to 4 Mbps

Category 3 UTP: Supports speed up to 16 Mbps

Category 4 UTP: Supports speed up to 20 Mbps

Category 5 UTP: Supports speed up to 100 Mbps

Category 5e UTP: Supports speed up to 100 Mbps with two pairs and up to 1000 Mbps with four pairs.

Category 6 UTP: Improved support for speeds up to 10 Gbps

Category 6a UTP: Expands the length of 10-Gbps
communication to the full 100 meters commonly associated with UTP cabling.

 

User Datagram Protocol (UDP)

 

·         A protocol used by some older applications, most prominently TFTP (Trivial FTP), to transfer files. UDP