Insy 3303 Scott Johnson Chapter 4-6

PDU

- Protocol data unit ThePDU contains information that is needed to transmit the message through the network.

Segment

- The Protocol Data Unit (PDU) at the transport layer is called a segment

DHCP

- The most common standard for dynamic addressing is Dynamic Host Configuration Protocol (DHCP).

RFP

- request for proposal (RFP) , requesting to buy tiems for company use.

BN

A backbone network (BN) is a large central network that connects almost everything on a single company site

Packet

A packet is the unit of data that is routed between an origin and a destination on the Internet

Routing protocols

A routing protocol is a protocol that is used to exchange information among computers to enable them to build and maintain their routing tables

Subnet

A subnet mask neither works like an IP address nor does it exist independently of them. Instead, subnet masks accompany an IP address and the two values work together. Applying the subnet mask to an IP address splits the address into two parts, an extended network address, and a host address.

ACK

Acknowledgement is a signal passed between communicating, processes, computers, or devices to signify acknowledgment .

Baselining

Baselining is a method for analyzing computer network performance. The method is marked by comparing current performance to a historical metric, or "baseline".

Common Carrier

Big phone carriers such as at&T

IOS

Cisco Internetwork Operating Systems (IOS)

Information Bits

Each communication protocol has both information bits and overhead bits. Information bits are those used to convey the user's meaning

EIGRP

Enhanced Interior Gateway Routing Protocol (EIGRP) is a dynamic hybrid interior routing protocol developed by Cisco and is commonly used inside organizations.

HDLC

High-level data link control (HDLC) is a formal standard developed by the ISO often used in WANs.

ICMP

Internet Control Message Protocol (ICMP) is the simplest interior routing protocol on the Internet. ICMP is simply an error-reporting protocol that enables computers to report routing errors to message senders. ICMP also has a very limited ability to update routing tables.

Error Detection

It is possible to develop data transmissionmethodologies that give very high error-detection performance. The only way to do error detection is to send extra data with each message. These error-detection data are added to each message by the data link layer of the sender on the basis of some mathematical calculations performed on the message (in some cases, error-detection methods are built into the hardware itself).The receiver performs the same mathematical calculations on the message it receives and matches its results against the error-detection data that were transmitted with the message. If the two match, the message is assumed to be correct. If they don't match, an error has occurred.

LAN

Local area network, which are connected by a back bone

Over head bits

Overhead bits are used for purposes such as error checking and marking the start and end of characters and packets.

Polling

Polling is the process of sending a signal to a client computer that gives it permissionto transmit.With polling, the clients store all messages that need to be transmitted.

Access Layer 167

Provides access to the network, network designs begins with it, primary wireless LAN.

QoS

Quality of Service (QoS) routing is a special type of connection-oriented messaging in which different connections are assigned different priorities. For example, videoconferencing requires fast delivery of packets to ensure that the images and voices appear smooth and continuous; they are very time dependent because delays in routing seriously affect the quality of the service provided

RTP

Real-Time Transport Protocol (RTP), TP contains information about the sending application, a packet sequence number, and a time stamp so that the data in the RTP packet can be synchronized with other RTP packets by the application layer software, if needed.

RSVP

Resource Reservation Protocol (RSVP) and Real-Time Streaming Protocol (RTSP) both permit application layer software to request connections that have certain minimum data transfer capabilities. As one might expect, RTSP is geared toward audio/video streaming applications, whereas RSVP is more general purpose.

RIP

Routing Information Protocol (RIP) is a dynamic distance vector interior routing protocol that is commonly used in smaller networks, such as those operated by one organization. The network manager uses RIP to develop the routing table

Segmenting

Segmenting means to take one outgoing message from the application layer and break it into a set of smaller segments for transmission through the network. It also means to take the incoming set of smaller segments fromthe network layer and reassemble them into one message for the application layer.

DNS

Server name resolution is the translation of application layer addresses into network layer addresses (e.g., translating an Internet address such as www.yahoo.com into an IP address such as 204.71.200.74).This is done using the Domain Name Service (DNS)

Error prevention

Shielding (protecting wires by covering them with an insulating coating) is one of the best ways to prevent impulse noise, cross-talk, and intermodulation noise. Moving cables away from sources of noise (especially power sources) can also reduce impulse noise, cross-talk, and intermodulation noise. For impulse noise, this means avoiding lights and heavy machinery. Locating communication cables away from power cables is always a good idea. For cross-talk, this means physically separating the cables from other communication cable

UDP

TCP/IP has a second type of transport layer protocol called User Datagram Protocol (UDP). UDP PDUs are called datagrams. Typically, UDP is used when the sender needs to send a single small packet to the receiver

LLC

The data link layer performs two main functions and therefore is often divided into two sublayers. The first sublayer (called the logical link control [LLC] sublayer) is the data link layer's connection to the network layer above it.

E-commerce Edge

The final network architecture component is the e-commerce edge. The e-commerce edge is a special LAN with a group of severs that enables electronic data exchange between the organization and the external entities with which it does business (such as its customers or suppliers)

Data Center

The fourth network architecture component is the data center, which contains the organization's servers (e.g., database servers, email servers).

Enterprise Edge

The last three components of the network architecturemake up the enterprise edge, the parts of the network that are at the edge of an enterprise campus and connect that campus to the rest of the world

Distribution Layer

The second network architecture component is the building backbone network, which some vendors call the distribution layer, because it distributes network traffic to and from the LANs.

MAC

The second sublayer (called the media access control [MAC] sublayer) controls the physical hardware.The MAC sublayer software at the sending computer controls how and when the physical layer converts bits into the physical symbols that are sent down the circuit

Core layer

The third network architecture component is the campus backbone (sometimes called the core layer), which connects all the buildings on one campus. The campus backbone is usually faster than the backbones we use inside buildings because it typically carriesmore traffic than they do. We use routers or layer 3 switches that do routing when we design the campus backbone.

Turnpike Effect

The turnpike effect is an expression that means that traffic increases much faster than originally forecast. It comes from the traffic forecasting that was done for the construction of the early interstate highways.

Throughput

Throughput is the total number of information bits received per second, after taking into account the overhead bits and the need to retransmit frames containing errors.

Reaper

To avoid attenuation, telephone circuits have repeaters or amplifiers spaced throughout their length. Usually on digital

TCP/IP

Transmission Control Protocol/Internet Protocol , TCP/IP is the transport/network layer protocol used On the Internet. It is the world'smost popular protocol set, used by almost all BNs and WANs. TCP/IP allows reasonably efficient and error-free transmission. Because it performs error checking, it can send large files across sometimes unreliable networks with great assurance that the data will arrive uncorrupted. TCP/IP is compatible with a variety of data link protocols, which is one reason for its popularity.

Transmission Efficiency

Transmission efficiency is defined as the total number of information bits (i.e., bits in the message sent by the user) divided by the total bits in transmission (i.e., information bits plus overhead bits). For example, let's calculate the transmission efficiency of asynchronous transmission

TCP connection

Whenever a computer transmits data to another computer, it must choose whether to use a connection-oriented service via TCP or a connectionless service via UDP.

Frame

With synchronous transmission, all the letters or data in one group of data are transmitted at one time as a block of data.This block of data is called a frame.

Synchronous Transmission

With synchronous transmission, all the letters or data in one group of data are transmitted at one time as a block of data.

Bottle neck

a circuit that is filled almost to its capacity and thus is the critical point that determines whether users get good or bad response times.

Stimulation

a mathematical technique inwhichthe network comes to life andbehaves as it would under real conditions, is used tomodel the behavior of the communication network.

Error control

error control is defined to be a layer-2 function—it is the responsibility of the data link layer.

BGP

is a dynamic distance vector exterior routing protocol used on the Internet to exchange routing information between autonomous systems—that is, large sections of the Internet. Although BGP is the preferred routing protocol between Internet sections, it is seldomused inside companies because it is large, complex, and often hard to administer.

Asynchronous Transmission

is often referred to as start-stop transmission because the transmitting computer can transmit a character whenever it is convenient, and the receiving computer will accept that character.

Building Block Design Process

many other organizations now use a simpler approach to network design that we call the building-block process. The key concept in the building-block process is that networks that use a few standard components throughout the network are cheaper in the long run than networks that use a variety of different components on different parts of the network.

NAK

negative acknowledgment, if the packet had a negative error

ARP 132

stands for address resolution protocol, basically translate the subnet to another computer then it is being processed by all computers in the same LAN..

Circuit loading

the amount of data transmitted on a circuit

Cost Assessment

the relative costs of the technologies are considered

ARQ 100

this stands for automatic repeat request. Once error has been detected, it must be corrected. The simplest, most effective, least expensive, And most commonly used method for error correction is retransmission. With retransmission, a receiver that detects an error simply asks the sender to retransmit the message until it is received without error. There's two types, stop and wait and continuous.

Address Resolution 130

to send a message, must be able to translate application layer address of the destination to the network layer address and translate that to the data link layer address

TLD

top level domain

Multicasting

which is sending messages to a group of computers rather than to one computer (which is normal) or every computer on a network (called broadcast)