Test 1 Flashcards
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What is ISP?
Internet Service Provider
What is LAN?
Local Area Network
What is TCP/IP?
Transmission Control Protocol/Internet Protocol. A set of communication protocols developed by the U.S. Department of Defense that enables dissimilar computers to share information over a network.
What is OSI?
Open Systems Interconnect
What are the seven layers of the OSI model?
- Application
- Presentation
- Session
- Transport
- Network
- Data Link
- Physical
What is ISO?
International Organization for Standardization
How many bits in a byte?
8 bits
How many bytes in a kilobyte?
1,000 bytes
How many bytes in a megabyte?
1 million
How many bytes in a gigabyte?
1 billion
What is the ASCII Table?
ASCII stands for American Standard Code for Information Interchange.
What is in the physical layer?
It defines hardware connections and turns binary into physical pulses (electrical or light). Repeaters and hubs operate at the physical layer.
What is a NIC?
Network Interface Card.Traditionally, an expansion card that enables a PC to link physically to a network. Modern computers now use built-in NIC’s, no longer requiring physical cards, but the term “NIC” is still very common.
What is the MAC address?
Media Access Control. The part of a NIC that remembers the NIC’s own MAC address and attaches that address to outgoing frames.
What is OUI?
Organizationally Unique Identifier, The first 24 bits of a MAC address, assigned to the NIC manufacturer by the IEEE.
What is IEEE?
Institue of Electronics and Electrical Engineers. The leading standards-setting group in the U.S.
What is ARP?
Address Resolution Protocol. A protocol in the TCP/IP suite used with the command-line utility of the same name to determine the MAC address that corresponds to a particular IP address.
What is topology?
The pattern of interconnections in a communications system among devices, nodes, and associated input and output stations. Also describes how computers connect to each other without regard to how they actually communicate.
What is a Ring Topology?
A network topology in which all the computers on the network attach to a central ring of cable.
What is a Bus Topology?
A network topology that uses a single bus cable that connects all of the computers in line. Bus topology networks must be terminated to prevent signal reflection.
What is a Mesh Topology?
Topology in which each computer has a direct or indirect connection to every other computer in a network. Any node on the network can forward traffic to other nodes. Popular in cellular and many wireless networks.
What is a Star Topology?
A network topology in which all computers in the network connect to a central wiring. (connected to a hub)
What is a Star Bus Topology?
A hybrid of the star and bus topologies that uses a physical star, where all nodes connect to a single wiring point such as a hub and a logical bus that maintains the Ethernet standards. One benefit of a star-bus topology is fault tolerance.
What is a Star-Ring Topology?
A hybrid of the Token Ring topology and the physical star.
What is a collision?
The result of two nodes transmitting at the same time on a multiple access network such as Ethernet. Both frames may be lost or partial frames may result.
What is a BNC Connector?
A connector used for 10Base2 coaxial cable. All BNC connectors have to be locked into place by turning the locking ring 90 degrees.
What is UTP?
Unshielded Twisted Pair. A popular cabling for phone and networks composed of pairs of wires twisted around each other at specific intervals. The more twists serve to reduce interference (also called cross-talk). The more twists, the less interference. Different categories: CAT 1-5, 5e, 6, 6a
What is an STP cable?
Shielded Twisted Pair. A cabling for networks composed of pairs of wires twisted around each other at specific intervals.
How much speed can CAT 3 Cabling operate?
Up to 16 Mbps 16/16
How much speed can CAT 4 operate?
Up to 20 Mbps
How much speed can CAT 5 operate?
Up to 100 Mbps 100/100
How much speed can CAT 5e operate?
Support for 100 Mbps using two pairs and support for 1000 Mbps using four pairs.100/1000
How much speed can CAT 6 operate?
UTP wiring with improved support for 1000 Mbps. 250/1000
What is fiber optics?
A high-speed physical medium for transmitting data that uses light rather than electricity to transmit data and is made of high-purity glass fibers sealed within a flexible opaque tube. Much faster than conventional copper wire.
What is FireWire?
An IEEE 1394 standard to send wide-band signals over a thin connector system that plugs into TV’s, VCR’s, TV cameras, PCs, and so forth. This serial bus developed by Apple and Texas Instruments enables connection of 60 devices at speeds ranging from 100 to 800 Mbps.
What is Plenum?
Usually a space between a building’s false ceiling and the floor above it. Most of the wiring for networks is located in this space. Plenum is also a fire rating for network cabling.
What is PVC?
Polyvinyl Chloride. A material used for the outside insulation and jacketing of most cables. Also a fire rating for a type of cable that has no significant fire protection.
What is Ethernet?
Name coined by Xerox for the first standard of network cabling and protocols. Ethernet is based on a bus topology. The IEEE 802.3 subcommittee defines the current Ethernet specifications.
What is an RJ Jack?
Registered Jack. Connectors used for UTP cable on both telephone and network connections.
What is CSMA/CD?
Carrier Sense Multiple Access/Collision Detection. Access method that Ethernet systems use in LAN technologies, enabling frames of data to flow through the network and ultimately reach address locations. Known as a contention protocol, hosts on CSMA/CD networks send out data without checking to see if the wire is free first. If a collision occurs, then both hosts wait a random time period before retransmitting the data.
What is Attenuation?
The degradation of signal over distance for a networking cable.
What is a Preamble?
A 64-bit series of alternating 1s and 0s, ending with 11, that begins every Ethernet frame. The preamble gives a receiving NIC time to realize a frame is coming and to know exactly where the frame starts.
What is a crossover cable?
A special UTP cable used to interconnect hubs/switches or to connect network cards without a hub/switch. Crossover cables reverse the sending and receiving wire pairs from one end to the other.
Lines 1 and 2 transmit. 3 and 6 receive.
What is TIA/EIA?
Telecom Industry Association/Electronics Industry Alliance. The standards body that defines most of the standards for computer network cabling. Many of these standards are defined under the TIA/EIA 568 standard.
What is a Bridge?
A device that connects two networks and passes traffic between them based only on the node address, so that traffic between nodes on one network does not appear on the other network. For example, an Ethernet bridge only looks at the MAC address. Bridges filter and forward frames based on MAC addresses and operate at Layer 2 (Data Link Layer) of the OSI seven-layer model.
What is a Broadcast Domain?
A network of computers that will hear each other’s broadcasts. The older term collision domain is the same, but rarely used today.
What is a STP?
Spanning Tree Protocol. A protocol that enables switches to detect and repair bridge loops automatically.
What is a switch?
A device that filters and forwards traffic based on some criteria. A bridge and a router are both examples of switches.
What is Full Duplex?
Any device that can send and receive data simultaneously.
What is Half Duplex?
Any device that can only send or receive data at any given moment.
What is Encapsulation?
The process of putting the packets from one protocol inside the packets of another protocol. An example of this is TCP/IP encapsulation in Ethernet, which places TCP/IP Packets inside Ethernet frames.
What is LLC?
Logical Link Control. The aspect of the NIC that talks to the operating system, places data coming from the software into frames, and created the FCS on each frame. The LLC also deals with incoming frames-processing those that are addressed to this NIC and erasing frames addressed to other machines on the network.
What is FCS?
Frame Check Sequence. A sequence of bits placed in a frame that is used to check the primary data for errors.
What is CRC?
Cyclic Redundancy Check. A mathematical method that is used to check for errors in long streams of transmitted data with high accuracy. Before data is sent, the main computer uses the data to calculate a CRC value from the data’s contents. If the receiver calculates a different CRC value from the received data, the data was corrupted during transmission and is resent. Ethernet frames have a CRC code.
What is a 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.
What is a Hub?
An electronic device that sits at the center of a star topology network, providing a common point for the connection of network devices. In a 10BaseT Ethernet network, the hub contains the electronic equivalent of a properly terminated bus cable. Hubs are rare today and have been replaced by switches.
What is a 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-FF.
What is an IP address?
The numeric address of a 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 witha valid subnet mask, which identifies the part of the IP address that is the network ID and the part that is the host ID.
What is a 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, an IP router looks only at the IP network number. Routers operate at Layer 3 (Network) of the OSI seven-layer model.
What is a packet?
Basic component of communication over a network. A group of bits of 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.
What is the Network Layer?
Layer 3 (OSI model) Moves packets between computers on different networks. Routers operate at the Network Layer. IP and IPX operate at the Network Layer.
What is the Data Link Layer?
Layer 2 (OSI model) Identifies devices on the Physical Layer. MAC addresses are part of the Data Link Layer. Bridges operate at the Data Link Layer.
What is the Transport Layer?
Layer 4 (OSI model) Breaks data down into manageable chunks. TCP, UDP, SPX, and NetBEUI operate at the Transport Layer.
What is the Session Layer?
Layer 5 (OSI model) Manages connections between machines. NetBIOS and Sockets operate at the Session Layer.
What is the Presentation Layer?
Layer 6 (OSI model) Which can also manage data encryption, hides the differences among various types of computer systems.
What is the Application Layer?
Layer 7 (OSI model) Provides tools for programs to use to access the network (and the lower layers). HTTP,FTP, SMTP, and POP3 are all examples of protocols that operate at the Application Layer.
What are the four layers of the TCP/IP Model?
- Link
- Internet
- Transport
- Application
What is UDP?
User Datagram Protocol. A protocol used by some older applications, most prominently TFTP (Trivial FTP), to transfer files. UDP datagrams are both simpler and smaller than TCP segments, and the do most of the behind-the-scenes work in a TCP/IP network.
What is the Link Layer (TCP/IP model)?
Layer 1. Similar to the OSI’s Data Link layer and Physical layers. The Link Layer consists of any part of the network that deals with frames.
What is the Internet Layer (TCP/IP model)?
Layer 2. Same as 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.
What is the Transport Layer (TCP/IP)?
Layer 3. 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 connectionless communication.
What is the Application Layer (TCP/IP)?
Layer 4. Combines the features of the top 3 layers of the OSI model It consists of the processes that applications use to initiate, control, and disconnect from a remote system.
Describe the typical network frame.
To-Recipient’s Mac Address; From-Sender’s MAC address; data; FCS
Describe the Ethernet frame.
Preamble. Recipient MAC. Sender MAC. Type. Data. Pad. FCS.
Describe 10BaseT.
Speed: 10 Mbps; Signal Type: Baseband; Distance: 100 meters; Node Limit: Max 1024 nodes per hub, Topology: Star-bus: Physical Star, logical bus; Cable Type: CAT 3 or better UTP cabling with RJ-45 connectors
Describe 100BaseT.
Speed: 100 Mbps; Signal Type: Baseband; Distance: 100 meters between hub and node; Node limit: 1024 hubs/node; Topology: Star-bus topology: physical star, logical bus; Cable Type: CAT5e or better
Describe 100BaseFX.
Speed: 100 Mbps; Signal Type: Baseband; Distance: 2 kilometers between the hub and node; Node limit: 1024 nodes/hub; Topology: Star-bus topology: physical star, logical bus; Cable Type: Multimode fiber-optic cabling with ST or SC connectors.
What is EMI?
Electromagnetic Interference. Interference from one device to another, resulting in poor performance in the device’s capabilities. This is similare to having static on your TV while running a hair dryer, or placing two monitors too close together and getting a “shaky” screen.
An Ethernet frame can have up to how many bytes?
1,500 bytes of data
Which standard specifies multimode cabling?
10BaseFL, 100BaseFX,
