Networking Fundamentals: Chapter 2

A packet sniffing application, used for network troubleshooting, analysis. This program captures packets on the NIC and decodes packet contents for readability.
A set of rules governing communication.
Layered Model
consists of various layers that enable the development and explanation of technology to be done on a modular basis. This allows for interoperability amongst different technologies within and between the different layers.
The medium used to transport information form a sender to a receiver
A process where multiple digital data streams are combined into one signal.
1) A network device that filters, forwards, and floods frames based on the destination of each frame. This switch operates at the data link layer on the Open System Interconnection (OSI) model.

2) A general term applied to an electronic or mechanical device that allows a connection to be established as necessary and terminated when there is no longer a session to support.

End Devises
a devise such as a desktop or mobile device that is used by an end user.
A computer system that accesses a service on another computer remotely by accessing the network.
Intermediary Devices
A device that connects directly to end user devices or provides end user routing to other networks. For instance, a router is an example of an intermediary device.
Host Access
An address of an network host. When talking about host addresses, we are usually talking the network layer address.
The process of transforming data from one form to another form. Line encoding is a process by which information from a source is converted into symbols to be communicated.
Local Area Network (LAN)
A local Network, or a group of interconnected local networks that are under the same administrative control. In the early days of networking, LANs were defined as small networks that existed in a single physical location. While LANs can be a single local network installed in a home or small office, the definition of LAN has evolved to include interconnected local networks consisting of many hundreds of hosts, installed in multiple buildings and locations.
A system internal to an organization such as a web site that is explicitly used by internal employees or students. Can be accessed internally or remotely.
A device that communicates over a network.
typically used to identify a certain process or service on a computer. When a remote device wishes to access a certain service on a server, for example, it will direct that data to a certain port that will identify the kind of service that device wants to use.
Logical Topography
The map of devices on a network and ho they communicate with one another. Shows the flow of data on a network.
A tool that shows the path in real-time from the source device to the destination device. It reports the IP addresses of all the routers (or hoops) in a path.
Protocol suite
Set of Communications protocols that implement the protocol stack on which networks run.
a group of computers that cooperatively. TCP/IP is an example of a protocol suite. The protocols involved in TCP/IP work together to provide communications amongst computer networks.
Institute of Electrical and Electronics Engineers
An international non-profit organization for the advancement of technology related to electricity. It has more then 360,000 members in around 175 countries.
Internet Engineering Task Force (IETF):
Task force consisting of over 80 working groups responsible for developing Internet standards. The IETF operates under the auspices of ISOC.
Web server
A server the responds to HTTP request and responding with the HTTP response data. A Web server also holds the directory structure of web sites and their associated images and other media files.
Web browser
GUI-based hypertext client application, such as Internet Explorer, Mosaic, and Netscape Navigator, used to access hypertext documents and other services located on innumerable remote servers throughout the WWW and Internet.
Hypertext Transfer Protocol (HTTP):
Is a method used to transfer or convey information on the Would Wide Web. Its original purpose was to provide a way to publish and retrieve HTML pages
Transition Control Protocol (TCP)
Is the protocol used as the basis of most Internet Services. It is used in conjunction with the Internet protocol (IP). It allows for reliable communication, ensuring that packets reach their intended destinations.
Internet Protocol (IP)
Network Layer Protocol in the TCP/IP stack offering a connectionless internetwork service. IP provides features for addressing, type-of-service specification, fragmentation and reassembly, and security. Documented in RFC 791.
Operating System
A software that preforms basic tasks such as controlling and allocating memory, prioritizing system requests, controlling input and output devices, facilitating networking, and managing file systems.
The wrapping of data in a particular protocol header.
Hyper Text Markup Language. Source code that web sites are written in. Web browsers download the source code from web servers and “translate” the code into visual format the end user to see.
The informational data at the beginning of a data block that devices use to process the datagram.
The layer two PCU witch has been encoded by a data link layer protocol for digital transmission. Some different kinds of frames are Ethernet frames and PPP frames.
The control information appended to data when data is encapsulated from network transmission.
Physical Address
A data-link-layer address, for example a MAC address.
International Organization for Standardization
An international standard-setting organization composed of representatives from various national standards bodies. Also called IOS. There are many ISO standers that span various industries ranging from quality standards of information security standards.
Error Recovery
A procedure that allows a user to recover from errors such as failure of either host system or transfer process.
User Datagram Protocol (UDP)
A connectionless transport layer protocol in the Transmission Control Protocol/Internet Protocol (TCP/IP) protocol stack. UDP is a simple protocol that exchanges datagram’s without acknowledgment or guaranteed delivery, and requires that error processing and retransmission be handled by other protocols. UDP is defined RFC 768.
E-mail client
Program used to download and send email. Email clients used pop3 to receive emails and use SMTP to send emails.
Streaming Media
Multimedia that is continually downloaded to the receiving host as the end-user views the material. This allows for the end-user to view the material without having to fully downloading the multimedia file to their computer.
User Datagram Protocol (UDP)
is a simple protocol that exchanges data without acknowledgements or guaranteed delivery. UDP relies on applications to handle error processing and retransmission.
Proxy Server
A server that acts as a kind of relay between the client and the destination server on the Internet. The proxy server acts on behalf of the client to the Internet go to the proxy server first. The proxy evaluates them, and if allowed, re-establish the requests on the outbound side of the Internet. This is also the case on inbound traffic.
The amount of data that can be transmitted in a certain amount of time. For digital bandwidth, it is usually in pits per second (bps). For analog bandwidth, it is expressed in cycles per second, or Hertz (Hz).
MAC Address
Standardized data link layer address that is required for every port or device the contacts to a LAN. Other devices in a network use these addresses to locate specific ports in the network and to create and update routing tables and data structures. MAC addressing are 6 bytes long and are controlling by the IEEE.
Logical Address
A network layer address. An address that can be changed at any time unlike a data-link-layer address, which is burned in the NIC.
IP Address
IP Address: Unique number that devices use in order to identify and communicate with each other on a computer network utilizing the Internet Protocol standard (IP).
Short for Internet Protocol version 4. It is the current version of Internet protocol.