Questions 1-250 Flashcards
(43 cards)
What is a “packet”?
A data unit for the Network Layer (layer 4) of the OSI model of computer networking. Data that is transmitted through this later is always called a packet.
What is a “frame”?
A data unit for Data Link layer (layer 2) of the OSI model of computer networking. Data that’s transmitted through this later of the network is always called a ‘frame’.
What is a “segment”?
A data unit of the Application to Transport Later (layers 6 and 7) of the OSI model of computer networking. Data transmitted through this layer of the network is always called a ‘segment’.
What is “same-layer interaction”?
Two computers use a protocol to communicate with the same network layer on another computer. A header is transmitted between the two computers to communicate what each computer wants to do.
What is “adjacent-layer interaction”?
On a single computer, one layer provides a service to a higher layer. The software implements the requests to the next lower network later to function.
What is a “protocol data unit (PDU”?
This refers to how data is encapsulated in a computer.
What is “encapsulation”?
This is the process of putting headers (and sometimes trailers) around data to indicate what layer or layers of the network the data is originating from. It is used when data is being sent by one computer from another.
What is “decapsulation”?
The process of removing headers and trailers around data to make sure it is received by a computer in a coherent form. It is used when data is received by a computer from another computer.
What is a “networking model”?
This is a general term that refers to standards that when followed by devices in a network allow all the devices within the network to communicate. Examples of these models include TCP/IP and OSI.
What is a “twisted pair”?
This is a transmission medium that consists of two insulated wires, with the wires twisted around each other in a spiral. An electrical circuit flows over the wire pair, with the current in opposite directions on each wire, which significantly reduces the interference between the two wires.
What is a “switched ethernet”?
An Ethernet that uses a switch, not a hub, so that the devices connected to one switch port don’t have to use the bandwidth available on another port. Switched Ethernet provides more capacity than shared Ethernet.
An example of this is the narrow road to a village being replaced with a series of roads for bikes, trucks, and pedestrians accordingly.
What is a “switch”?
A network device that filters, forwards, and floods Ethernet frames (aka data packets) based on the destination address.
What is a “straight through cable”?
In Ethernet, a cable that connects the wire to pin number 1, pin 2 on one end to pin 2 on the other. In general, this cable runs through the wire to connect the pins for both sending and receiving data.
What is “shared Ethernet”?
An Ethernet uses a hub, or even the original coaxial cabling (a cable that is used to transmit radio signals, but also works with Internet connections) to transmit data. This causes devices to take turns sending data because they have to share the available bandwidth along with all the other functions of the hub.
An analogy is that the Ethernet is like a two-lane road as if the road is the only way to get into a town.
What is “protocol type field”?
a field in the LAN header that identifies the type of header (aka the previous protocol used) that follows the initial LAN header.
Protocol type fields includes the DIX Ethernet Type field, the IEEE 802.2 DSAP field and the SNAP protocol field.
What is a “pinout”?
A description, either in words or pictures, of how electronic signals are transmitted through each pin and receptacle in a connector, which connects the Ethernet cord to the computer.
What is a “hub”?
A LAN device that provides a centralized connection point for LAN cabling, which focuses on repeating any received electrical signal out of all other ports, thereby creating a logical bus-tech speak for a common electrical path along which data can be sent from one computer to another computer.
What is “half-duplex”?
Any communication in which only one device at a time can send data.
What is “classful addressing”?
This concept is that an IPv4 address has three parts: the network, subnet, and host. These are defined by the subnet mask and the Class A, B, and C rules for network calssification.
What is “classless addressing”?
The concept that an IPv4 address has two parts: the prefix part and the host part - as defined by the mast, with no consideration of Class A, B, and C rules for network classification.
What are “binary masks”?
These are a string of binary numbers (1s and 0s)s that are converted to create a specific output value. In the case of networking, this value is the subnet mask.
What is the “Dotted Decimal Notation (DDN)”?
This is a presentation format for subnet masks in which 8 bits of binary numbers are converted into a decimal equivalent value.
What is a “decimal mask”?
a subnet mast that is done in dotted decimal notation.
What is a “prefix notation”?
The is a shorter way to write a subnet mast in which the number of binary 1s in the mask is simply written in decimal.
For instance, /24 denotes the subnet mast with 24 binary 1 bits in the subnet mask. The number of bits of value binary 1 in the mast is considered to be the perfect length.
