CompTIA Network+ Ch.2
Error control
A connection service in the LLC sub-layer of the data link layer, that allows the recipient of data to let the sender know if the expected data frame was not received or if it was received, but it corrupted.
Flow control
A connection service in the LLC sub-layer of the data link layer, that limits the amount of data a sender can send at one time
MUXing
Abbreviation for Multiplexing
The OSI Model (top down)
Application Presentation Session Transport Network Data Link Physical
Cyclic Redundancy Check
CRC means...
physical (addressing)
Data link layer uses what kind of addressing
port number
How the application layer of the TCP/IP stack protocols are identifiable
Network Layer (layer 3)
IP addresses reside at which layer of the OSI reference model?
Internet Protocol
IP means....
Synchronizing transmissions
In the LLC sub-layer of the data link layer, Process by which senders and receivers of data frames need to coordinate when a data frame is being transmitted and should be received.
Isochronous transmissions
In the LLC sub-layer of the data link layer, a method of performing a synchronization, when network devices look to a common device in the network as a clock source
Asynchronous transmissions
In the LLC sub-layer of the data link layer, a method of performing a synchronization, when network devices reference their own internal clocks
Synchronous transmissions
In the LLC sub-layer of the data link layer, a method of performing a synchronization, when two network devices that want to communicate between themselves must agree on a clocking method to indicate the beginning and ending of data frames.
Connection services
In the LLC sub-layer of the data link layer, a service in which acknowledgment messages that the sender receives from the recipient device as feedback.
Transport Layer (Layer 4)
In the OSI Model, Acts as a dividing line between the upper layers and lower layers. Specifically, messages are taken from the upper layers (5-7) and encapsulated into segments for transmission to the lower layers (1-3). Similarly, data streams from the lower layers are decapsulated and sent to Layer 5 or some other upper layer.
Data Link Layer (Layer 2)
In the OSI Model, Concerned with the packaging of data into frames and transmitting those frames on a network, performing error detection/correction, uniquely identifying network devices with an address (MAC), and handling flow control.
Physical Layer (Layer 1)
In the OSI Model, Concerned with the transmission of bits on a nework.
Application Layer (Layer 7)
In the OSI Model, It provides application services to a network. An important concept is that end-user applications do not reside at the application layer; supports services USED by end-user applications. (email, web, ftp). Also advertises available services.
Network Layer (Layer 3)
In the OSI Model, Primarily concerned with forwarding data based on logical addresses.
Presentation Layer (Layer 6)
In the OSI Model, Reponsible for the formatting of data being exchanged and securing the data with encryption.
Session Layer (Layer 5)
In the OSI Model, Responsible for setting up, maintaining and tearing down sessions.
Method of transmitting on the media
In the data link layer, in the MAC sub-layer, a strategy for determining when a device is allowed to transmit on the media.
Physical Addressing
In the data link layer, type of addressing using MAC addressing in which the first 24 bits of the 48-bit is the vendor code, and the last 24 bits are unique values.
how a Level 3 device knows how to reach various network addresses.
In the network layer, Route discovery and selection means....
store-and-forward (network)
In the network layer, a network using message switching is sometimes called...
Packet reordering
In the network layer, allows packets to be placed in the appropriate sequence as they are sent to the receiver.
Flow control (congestion control)
In the network layer, helps prevent a sender from sending data more rapidly than the receiver is capable of receiving the data.
switching
In the network layer, making decisions about how data should be forwarded
Packet (switching)
In the network layer, type of switching in which a data stream is divided into packets and routed
Circuit (switching)
In the network layer, type of switching in which a dedicated communication link between two parties are built up in order for those parties to communicate, and torn down when communication is done, similar to a phone call
Message (switching)
In the network layer, type of switching that is usually not well-suited for real-time because of latency; a data stream is divided into messages, which are tagged with the destination, and can sometimes be stored along the path to the receiver.
Broadband
In the physical layer, Bandwidth usage that divide the bandwidth into different channels such as a cable modem.
Baseband
In the physical layer, Bandwidth usage that uses all the available frequencies on a medium to transmit data such as Ethernet.
Asynchronous synchronization
In the physical layer, a sender indicates that it's about to start transmitting by sending a start bit to the receiver, it sends a stop bit to indicate that it has finished its transmission.
Multiplexing strategy
In the physical layer, allows multiple communications sessions to share the same physical medium
Frequency-division multiplexing (FDM)
In the physical layer, divides a medium's frequency range into channels, and different communication sessions transmit their data over different channels.
Statistical time-division multiplexing (StatTDM)
In the physical layer, dynamically assigns times slots to communications sessions on an as-needed basis.
Time-division multiplexing (TDM)
In the physical layer, supports different communication sessions on the same physical medium by causing the sessions to take turns.
Synchronous synchronization
In the physical layer, synchronizes the internal clocks of both the sender and receiver to ensure that they agree on when bits begin and end.
Synchronizing bits
In the physical layer, when one bit stops and another bit starts
Sliding window
In the transport layer, Where window size begins with one segments, if there is a successful acknowledgment of that one segment, the window size doubles to two segments, and so on with exponential increase in window size until the receiver does not acknowledge successful receipt or configured maximum window size is reached.
User Data-gram Protocol (UDP)
In the transport layer, a connection-less transport protocol that provides unreliable transport
Transmission Control Protocol (TCP)
In the transport layer, a connection-oriented transport protocol, that provides reliable transport
Windowing
In the transport layer, one or more segments are sent at one time, and a receiver can acknowledge the receipt of all the segments in a window with a single acknowledgment
Buffering
In the transport layer, when a device allocates a chunk of memory (sometimes called a buffer or queue) to store segments of bandwidth is not currently available to transmit those segments.
Logical Link Control
LLC means...
Logical (topology)
Layer 2 devices in the MAC sub-layer, view a network as this type of topology
Media Access Control
MAC means...
The TCP/IP Stack Layers (bottom up)
Network Interface Internet Transport Application
logical (addressing)
Network layer uses what kind of addressing
OSI
Open Systems Interconnection Reference Model
Protocol Data Unit
PDU means....
well-known ports
Ports numbered 1023 and below are called...
ephemeral ports
Ports numbered above 1023 are called...
Transmission Control Protocol
TCP means...
5, 6, and 7 (session, presentation, and application)
TCP/IP stack's Application layer encompasses the technologies added by what layers of the OSI Model?
3 (network)
TCP/IP stack's Internet layer encompasses the technologies added by what layers of the OSI Model?
1 and 2 (physical and data link)
TCP/IP stack's network interface layer encompasses the technologies added by what layers of the OSI Model?
4 (transport)
TCP/IP stack's transport layer encompasses the technologies added by what layers of the OSI Model?
Internet Layer
TCP/IP stack, Maps to L3 of the OSI (network layer). Routed protocols (IP, IPX, Appletalk), the layer focuses on IP as the protocol to be routed through a network.
Transport Layer
TCP/IP stack, Maps to L4 of the OSI (transport layer). The two primary protocols found are TCP and UDP.
Application Layer
TCP/IP stack, Maps to L5,L6,L7 os the OSI (session, presentation, application). Protocols are listed by port numbers.
Network Layer
TCP/IP stack, encompasses the technologies adressed by L1 and L2 of the OSI model. (Physical and Data Link)
Time-Division Multiplexing
TDM means...
Data link layer
The layer with these devices include switches, bridges, and NIC. pg40
Physical Layer (Layer 1)
The layer with these devices, hubs, wireless access points, and network cabling, repeater, wireless access points...
TTL
The value in this field is decremented by one every time this packet is routed from one IP network to another, if the value ever reaches 0, the packet is discarded from the network
TCP (Transmission Control Protocol)
This type of communication uses windowing or sliding window.
physical topology
Topology of the Layer 1 of OSI
TCP (Transmission Control Protocol)
Type of physical layer protocol that does error checking
UDP (User Data-gram Protocol)
Type of physical layer protocol that does not do error checking
User Data-gram Protocol
UDP
Network Basic Input Output System
What does NetBIOS stand for?
Time-to-Live
What does TTL stand for?
Below 1024 (1023 and below)
What is the range of well-known TCP and UDP ports?
Setting up
What part of the session layer is Negotiating services require during the session?
Maintaining
What part of the session layer is acknowledging receipt of data?
Setting up
What part of the session layer is assigning numbers to a session's communications flows to uniquely identify each flow?
Setting up
What part of the session layer is checking user credentials?
Setting up
What part of the session layer is negotiation which device begins sending data?
Maintaining
What part of the session layer is reestablishing a disconnected session?
Maintaining
What part of the session layer is transferring data?
Tearing down
What part of the session layer is when a session can be disconnected based on the mutual agreement of the devices in the session?
Baseband
Which approach to bandwidth usage consumes all the available frequencies on a medium to transmit data?
Data link layer (layer 2)
Which layer of the OSI reference model contains the MAC and LLC sub-layers?
H.323
Which session layer protocol can help set up, maintain, and tear down a voice or video connection?
Transport layer (layer 4)
Windowing is provided at what layer of the OSI reference model?
application services
a function of the application layer that includes file sharing and email
service advertisement
a function of the application layer that includes sending out advertisements, making the availability of a service known to other devices on the network
ICMP (Internet Control message protocol)
a transport layer protocol that is used by utilities such as ping and traceroute
NetBIOS
an application programming interface that allows computer-to-computer communication over a small LAN and is one example of a session layer protocol
PDU
bits that are grouped together
Queue
has a finite capacity and can overflow when buffering
data formatting
in the presentation layer, formatting the text or other types of data using either ASCII or EBCDIC in a format that allows compatibility between the communicating devices
encryption
in the presentation layer, this can be used to scramble up the data in such a way that if the data were intercepted, a third party would not be able to unscramble it.
Multiplexing
putting stuff together
CRC (Cyclic Redundancy Check)
synchronous communication that runs a mathematical algorithm on the data.
Demultiplexing
taking stuff apart
Binary (1s and 0s)
the presence or the absence of voltage on a wire can be represented by....
application programming interface
what does API stand for?
American Standard Code for Information Interchange
what does ASCII stand for?
Extended Binary Coded Decimal Interchange Code
what does EBCDIC stand for?
