CCNA Certification Institute】 【】 weak Chinese English vocabulary analysis..

<br> CCNA Introduction to Cisco's most basic certification, which tests the concept and the emphasis on network theory, for starters, many professional English terminology difficult to understand, leading to student learning progress dimension difficult. .CISCO certification of the original series of teaching materials, professional product of high frequency words, as long as the candidates are familiar with this, I believe it will learn more with less. .IEEE802.3 10BaseT ----- original part of the standard, 1OBaseT is 1OMb / s baseband Ethernet specification that uses two pairs of twisted-pair cable (Category 3, Category 4 or 5 class), a pair of used to send data .the other for receiving data. .1OBaseT each range limitation of about 100 meters. .See Ethernet and IEEE 802.3. .1OOBaseT ----- standards-based IEEE 802.3U, 1OOBaseT UTP wiring using baseband Fast Ethernet specification. .When no traffic occurs. .1OOBaseT Send link pulse on the network (more than 1OBaseT used contain more information.) .See 10BaseT, Fast Ethernet and IEEE 802.3. .100BaseTX ----- standards-based IEEE 802.3U, 100BaseTX is the use of two pairs of UTP or STP wiring 10OMb / S baseband Fast Ethernet specification. .First on line to receive data; second on line to send data. .To ensure correct signal timing, a 100BaseTX segment can not exceed 100 meters long. .A & B bit signaling (A and B bit signaling )----- for T-1 transmission equipment, sometimes referred to as "the first 24-channel signaling." .In this program, each T-1 in the sixth frame of each channel used to send the monitor a bit signaling information. .AAA ----- authentication (Authentication), authorization (Authorization) and statistics (Accounting) Cisco developed a provider of network security systems. .Played, see authentication. .authorization and accounting AAL ATM Adaptation Layer ----- a data link layer service-related sub-layer, data link layer to accept data from other applications and the ATM layer with one byte of the payload section 48 .. .AAL CS and SAR are the two sub-layers. .At present, ITU-T recommendations of the four AAL is AAL1, AAL2, AAL3 / 4 and AAL5. .AAL sources used by them - the distinction between regular destination, whether they are CBR or VBR, but also whether they are used for connection-oriented or connectionless mode data transfer. .See AAL1, AAL2, AAL3 / 4, AAL5, AT and ATM layerAAL1 ATM Adaptation Layer 1 ----- ITU-T recommendations one of the four AAL for connection-oriented and requires a constant bit rate of the time-sensitive .services, such as synchronized traffic and uncompressed video. .See AAL2 ATM Adaptation Layer played 2 ----- ITU-T recommendations one of the four AAL for connection-oriented, variable bit rate support services, such as voice traffic, see AAL AAL3 / 4 ATM Adaptation Layer .One of the four AAL 3/4-----ITU-T proposed to support also supports connection-oriented connectionless link. .Mainly used in the ATM network to send SMDS packets. .See AAL AAL5 ATM Adaptation Layer 5 ----- ITU-T recommendations one of the four AAL, mainly used to support VBR connection between the business side to send the classic IP over ATM and LANE traffic. .The AAL recommendation to use the easiest SEAL, provide a lower bandwidth overhead and simpler processing requirements, but also providing reduced bandwidth and error recovery capabilities. .See AAL AARP AppleTalk Address Resolution Protocol ----- in the AppleTalk protocol stack of the data link addresses to network addresses AARPprobepackets (AARP )----- AARP probe packets sent packets to determine a non- .Extended AppleTalk network, a given node ID is used by another node. .If the end of the node ID is used, the node can be used to send the node ID, if the node ID is already in use, the sending node will select a different ID and sends more AARP probe packets. .See AARP ABM Asynchronous Balanced Mode ----- When two stations can begin transmission, ABM is a peer support between the two stations, and point to point communication of HDLC (or one derived protocols) communication technology ABR region .----- border routers in one or more of the OSPF OSPF area border router, ABR was used to connect OSPF areas to the OSPF backbone area access layer (the access layer )----- Cisco three-layer hierarchical model .layer. .Access layer enables users to access the Internet. .access link (link )----- access the switch using a link, is a virtual VAN (VLAN) part. .Link link to transfer information from more than one VLAN. .ccess list ()----- router to access the table a set of test conditions kept it on the network to determine a variety of business "traffic of interest," and from the router. .access method ()----- network device access methods to obtain access to the million-style network. .access rate (access rate )----- defined circuit bandwidth rate. .For example, T-1 access circuit rate of 1.544Mb / s. .In the Frame Relay and other technologies, can be a part of the T-1 connection (such as 256kb / s), but the access rate and clock rate is still I.544Mb / S access server (ie access server )----- .The so-called "network access server", it is a communication process, through the network and terminal emulation software to connect to asynchronous devices - a LAN or WAN, to provide the support agreement synchronous or asynchronous routing. .accounting (statistics )----- AAA is one of the three components. .Statistical model for security auditing and logging capabilities to provide acknowledgment (confirmation )----- from a network device to another network device authentication, that an event has occurred. .Can be abbreviated as ACK. .Control NAK. .Allowed cell rate ACR ----- ATM Forum for ATM traffic management definition of a name. .Congestion control measures using dynamic control, ACR minimum cell rate (MCR) and peak cell rate (PCR) between the changes. .See MCR and PCR active monitor (Activity Monitor )----- the mechanism used to manage the token ring. .Ring with the highest MAC address of the network nodes into Activity Monitor and manage to prevent the loop and ensure that the token is not lost like the task. .address learnmng (address learning )----- used in conjunction with the transparent bridge was informed that all devices on the Internet hardware address. .Then switch with a known hardware address (MAC) filtering the network address mapping (address mapping )----- by network address from one format to another format, this method allows alternate operation of different protocols address mask .(address mask )----- a bit combination descriptor, it identifies which part of an address on behalf of the network or subnet and which part represents hosts. .Sometimes referred to as the mask. .Played see subnet mask address resolution (ARP )----- addressing scheme used to resolve differences between a computer process. .Address resolution method to track the general definition of a network layer (third layer) addresses to data link layer (second layer) address. .See the address mapping. .adjacency (adjacent to the use of common media section )----- neighboring routers and end-established relationship between the nodes to exchange routing information. .administrative distance (the distance )----- management between 0 and 255, a number that represents a routing value of the credibility of information sources. .The smaller the value, the higher the level of constitutional integrity of the administrative weight (weighted )----- management network administrator for a given network link specified rating value. .It is PTSP exchange one of four link metrics, used to test the reliability of ATM network resources. .ADSU ATM data service unit (ATM Data Service Unit )----- by HSSI-compatible mechanism for ATM networks connected to the terminal adapter. .See DSU advertising (notice )----- routing or service updates are sent to a given interval of the process, allowing other routers on the network can maintain a current record of AEP AppleTalk routing response protocol (AppleTalk Echo Protocol): the two .connectivity between two AppleTalk nodes of a test in which a node sends a packet to another node and to receive feedback in response to or copy. .AFI authority and format identifier (Authority and Format Identifier )----- NSAP ATM address part of its ATM address depicting the type and format of the IDI section. .AFP AppleTalk File Protocol (AppleTalk Filing Protocol )----- a presentation layer protocol, supporting AppleShare and Mac OS file sharing, allows users to share files on the server and applications. .AIP ATM Interface Processor (ATM Interface Processor )----- support AAL3 / 4 and AAL5. Cisco 7000 series routers that interface to minimize performance bottlenecks UNI. .Participation AAL3 / 4 private AAL5. .algorithm (algorithm used to solve a problem )----- a set of rules or processes. .Algorithm is generally used in the network traffic from that source the best route to its destination. .alignmenterror (alignment error )----- an Ethernet network error occurred, in which the frame received bit extra, that a number is not divisible by 8. .Alignment errors are usually caused by the conflict the result of frame damage. .all-routes explorer packet (full routing probe packets across the entire SRB )----- a network to detect packet trace to a given destination, all possible paths. .Probe packets, also known as the Global Environment. .See also explorer packet, local explorer packet, and Spanning explorer packet. .AM amplitude modulation (Amplitude modulation )----- changes from the representative of the carrier signal amplitude modulation method of a message. .See modulation. .AMI Alternate Mark Inversion (Alternate Mark Inversion )----- T-1 and E-1 circuit on a line code, each bit cell used during the 0 "01," said an alternate peer "11" or " .00, "said. .Sending device must maintain a density of AMI but not independently of the data stream. .Binary code, also known as Alternate Mark Inversion. .Control B8ZS. .See ones density. .amplitude (analog or digital waveform amplitude )----- maximum. .analog transmission (analog transmission )----- by the signal amplitude, frequency and phase information that different combinations of signal transmission. .American National Standards Institute ANSI (American National Standards Institute )----- by the U.S. companies, governments and members of other volunteer organizations, it coordinates standards-related activities, and approval of the American National Standards represent the United States in the International Organization for Standardization .. .ANSI help in communications, networks and technology to create international and U.S. standards. .It has been published for engineering products and technologies Ding more than 13,000 kinds of standards ranging from screws to the network protocol rib, all-inclusive. .ANSI is a member of IEC and ISO. .anycast ----- an ATM address, it shared by multiple end systems, allowing the request sent to a special service node. .AppleTalk ----- Apple Computer Inc. Macintosh environment in the design of communication protocols using the group, currently has two versions. .Early Phase 1 protocol to support a physical network, there is only one network number that resides in a region. .Later Phase 2 protocols support more than one single physical network, logical network, allows the network to exist in multiple areas. .See zone. .Application layer (application layer )----- OSI reference network model of the seventh floor, in addition to the OSI model the application (such as email or file transfer) to provide services. .B8ZS Binary 8 zero substitution ----- binary encoding of a line, connecting the remote interpretation in the T-1 and E-1 circuit transmission link eight consecutive zero, it uses a special code .instead. .The density of this technology to ensure that a data stream from the constraints. .Also known as bipolar 8-zero substitution. .Contrast AMI. .See ones density. .backbone (backbone )----- essential part of the network, which provides to send to other networks and from other network traffic initiated by the main path. .back end (the back-end )----- provide services for the front end of a node or software program. .See the server. .bandwidth (the bandwidth used )----- network signal between the highest and lowest frequency interval. .Usually, it involves a network protocol or media rated throughput. .bandwith on demand (BoD, on-demand bandwidth )----- This feature allows an additional B channel is used for a specific connection to increase the amount of available bandwidth. .baseband (baseband )----- a feature of network technology, it uses a carrier frequency. .Ethernet is an example. .Also called "narrowband." .Of broadband. .baseline (baseline )----- baseline information includes historical data about the network and routine use of information. .This information can be used to determine whether the network may cause problems recent changes. .Basic Management Setup (basic management set up) ----- Cisco router in building mode. .Only to provide adequate management and configuration to make the router work, so that only one can telnet to the router and configure it. .baud (bits per second baud )----- (b / s) of the synonym, if each signal element represents a bit to say. .It is a unit of signaling speed equivalent to separate the signals transmitted every second number of elements. .BDR Backup Designated Router (Backup Designated Router )----- an OSPF network is used to prevent the failure of the backup designated router. .beacon (beacon )----- a FBDT device or token ring frames, it noted that a serious problem in the ring, such as a broken cable. .Beacon frame contains the address of the downstream station. .See also failure domain. .BECN explicit congestion after the pass between the tubes (Backward Explicit Congestion Notification )----- BECN congestion encountered by the frame relay network path bit set in the frame. .DTE receiving frames with the BECN may ask to take the necessary high-level protocol flow control measures. .Contrast FECN. .BGP4 BGP Version 4 (BGPversion4 )----- most common on the Internet inter-domain routing protocol version 4. .BGP4 routing to support and use the computer system CTDR to reduce the size of the routing table. .See CIDR. .BGP Identifier (BGP identifier )----- the buildings to identify the segment that contains a value of BGP speakers. .This is the router sends a BGP OPEN message, choose a random value. .BGP neighbors (BGP neighbors to start a communication process )----- dynamic routing of information in exchange for the two routers running BGP; they use the OSI reference model layer 4 of a TCP port. .In particular, the use of TCP port 179. .Also known as "BGP peers are." .BGP peers (BGP peer who )----- See the BGP neighbors. .BGP speaker (BGP speaker advertises its prefixes or routing )----- router. .bidirectional shared tree (bi-directional shared tree multicast shared tree )----- a way. .This method allows group members from the source or near the RP) receives the data. .See RP (rendezvous point). .binary (a binary 1 and 0 with )---- character count of two ways. .Binary counting system as the basis for the expression of all the digital information. .binding (binding )----- LAN configured in a network layer protocol to use a frame type. .BIP-bit cross-parity (Bit Interleaved Parity )----- ATM used to monitor link error in a way, in the previous block or frame of the link cost to send a check bit or word. .This allows that transmission bit errors and for the maintenance of information transmission. .BISDN Broadband TSDN (Broadband ISDN )----- for the management of high-bandwidth technologies (such as video) to create the ITU-T standard. .BISDN currently uses ATM technology and SONET-based transmission circuits to provide 155Mb / s and 622Mb / s and higher data rates between. .See also BRI, ISDN and PRI. .bit (bit, bit )----- a number; a 1 or a 0.8 to form a byte. .bit-oriented protocol ()----- bit-oriented protocols, regardless of content and frame, type of data link layer protocol is responsible for transmission frame. .And byte-oriented protocol, more efficient bit-oriented protocols, and can reliably full-duplex operation. .Compared byte-oriented protocol. .block size (block size )----- available hosts in a subnet number. .Block size can generally be used to increment 4,8,16,32,64 and 128. .Boot ROM (Boot ROM )----- for the router to router to release the boot mode. .Then boot mode using an operating system boot the device. .The ROM can also hold a small Cisco IOS. .boot sequence (boot sequence )----- define how a router guide. .Configuration register tells the router where to boot from the IOS and how to configure. .bootstrap protocol (boot protocol used to dynamically allocate )----- IP address and gateway to the requesting client agreement. .border gateway (border gateway )----- easy in autonomous systems with different communications router, a router. .border peer (such as those boundaries on a peer group )----- management of equipment, it exists in the edge of a level design. .When any member of such group wants to find a resource, it sends a probe to the boundary of the other person. .Then the other person on behalf of the border router to forward the request the request, thus eliminating the duplication of traffic. .border router (border router )----- usually open shortest path first (OSPF) is defined as an area connected to the backbone area routers. .But the border routers can also be connected to the Internet router company. .See OSPF. .BPDU Bridge Protocol Data Unit (Bridge Protocol DataUnit )----- bridges in the network to exchange information, define the interval to send an initialization packet spanning tree protocol. .Basic Rate Interface BRI (Basic Rate Interface )----- easy in the video, data and voice communications between the circuit-switched ISDN interface, which consists of two B channels (each of 64Kb / s) and one D channel (16Kb / .s) composition. .Contrast PRT. .See BISDN. .bridge (Bridge )----- network connection between them two and a device to transmit data packets. .Two must use the same protocol to communicate. .Bridging function in the data link layer, OSI reference model is layer 2. .The purpose of the bridge is based on a special frame MAC address filtering, send or spread of any into the frame. .bridge group (group )----- bridge configuration in the router to use the bridge, the bridge group defined by a unique number. .Bridge network traffic in the same set of numbers between the bridge all the interfaces. .bridge identifier (bridge ID )----- used for Layer 2 switched network discovery and selection in the root bridge. .Bridge ID is the bridge priority and MAC address based on the combination. .bridge priority (the priority )----- set bridge STP bridge priority. .By default, the priority of all bridges is set to 32768. .bridging loop (loop )----- bridge network bridge, if a network has more than one link and open the STP protocol when the end of the loop. .broadband (cable broadband )----- in a few separate multiplexed signals of a transmission technology. .Telecommunications, broadband at more than 4KHz (typical voice grade) bandwidth channel classification. .LAN technology in its use of analog signaling by coaxial cable classification. .Contrast baSeband. .broadcast (radio )----- a data frame or packet is transmitted to the local segment (defined by the broadcast domain) on each node. .Broadcast is indicated by the broadcast address, the destination network and host address bits are all 1. .Also known as "local broadcasting." .Contrast directedbroadcast. .broadcast address (broadcast address )----- addressing the logical addressing and hardware used. .Logical addressing, the host address for the whole 1. .For the hardware address, hardware address in hex for the entire 1 (ie all the F). .broadcast domain (Radio City )----- received from a device group, issued a broadcast frame on any device the device group. .Because they do not forward broadcast frames, broadcast domains are usually surrounded by a router. .broadcast storm (on the network broadcast storm )----- an unwelcome event, which consists of any number of radio caused by simultaneous transmission segment. .Its appearance may run out of network bandwidth, resulting in overtime. .buffer (buffer )----- dedicated to processing and transmission of the data storage area. .Buffer used to receive / store from the fast devices are usually sporadic bursts to compensate differences in processing speed. .Data to be sent in the receipt of the person's information is stored in advance. .Also known as the "information buffer." .bursting (burst )----- number of technologies (including ATM and Frame Relay) are considered to be sudden. .This means that user data can exceed the bandwidth reserved for the connection is normal, but can not exceed the port rate. .An example of this situation on a T-1 128Kb / s Frame Relay CIR-dependent vendors, there may be short more than 128Kb / s rate for transmission. .bus topology (bus topology LAN )----- off a straight line structure in which each station from the transmission network, the length of the media is copied by all other stations to receive. .Contrast ring and star. .bus (bus) by any physical path (usually copper )----- wire or a digital signal can be used to send data from a part of the computer to the other part. .BUS BUS ----- simulation in the LAN, is responsible for parsing all the radio and with unknown (not registered) address of the packet into ATM virtual circuits required for point to point hardware or software. .See LANE, LEG, LEGS, and LES. .BX.25 AT & T on the use of X.25. .See X.25. .bypass mode (bypass mode )----- delete an interface FDDI and Token Ring network operation. .bypass relay (relay bypass )----- apply to a Token Ring interface can ring off and effectively out of a device. .byte (byte) 8 bits. .See octet. .byte-oriented protocol (byte-oriented protocol )----- order to mark the boundaries of the frame, a user character set to use the special character of the data link communications protocol. .These agreements generally have been replaced by bit-oriented protocols. .Contrast bit-oriented protocol. .cable range (cable range) in the extended AppleTalk network, the nodes on the network using the existing number ranges assigned. .Cable can be a range of values can also be a sequence of several successive network number. .Node address is the scope of the value of their cable set. .cable range (cable range )----- the extended AppleTalk network, the nodes on the network using the existing number ranges assigned. .Cable can be a range of values can also be a sequence of several successive network number. .Node address is the data circuit-terminating equipment (data circuit terminating equipment )----- DCE to DTE equipment between the timing. .data compression (data compression )----- See compression. .data direct VCC (VCC )----- ATM data directly between the two LEG established a two-way point to point virtual control connection (VCC), is defined by the Phase 1 LAN emulation is one of three data connections. .Because the data directly to VCC does not guarantee QoS, they are usually set aside for the UBR and ABR connections. .Contrast control distribute VCC and control direct VCC. .data encapsulation (data encapsulation )----- a protocol agreement in the data information in another part of the process of being packaged or contained. .In the OSI reference model, the data flowing through the stack, each layer of the upper layer of packaging it immediately. .data frame (data frame )----- OSI reference model data link layer protocol data unit on the package. .Encapsulated packets from the network layer and to prepare the network data transmission medium. .datagram (as a network layer datagram )----- without pre-established virtual circuit unit and a transmission on the media logical collection of information. .IP datagrams have become the main Internet unit of information. .Layers in the OSI reference model, the term cell (cell), frame (frame), packet (message) and section (segment) also define these logical information groupings. .Data Link Control layer (data link control layer )----- SNA architecture model layer 2, which is responsible for a given physical link to transfer data and the equivalent of OSI reference model data link layer. .Data Link layer (data link layer )----- OSI reference model layer 2, which ensures reliable data transmission through the physical link, mainly related to the physical addressing, line discipline, network topology, error notification, the frame .order delivery and flow control. .IEEE has further divided this layer as the MAC sublayer and LLC sublayer. .Also known as link layer. .With SNA data link control layer in comparison. .See the Application layer, LLC, MAC, Network layer, Physical layer, Presentation layer, Session layer and Transport layer. .data terminal equipment (data terminal equipment )----- see DTE. .DCC Data Country Code (Data Country Code )----- ATM Forum developed the design for the private network to use one of two ATM address formats, "compared ICD. DCE data communications equipment (JIA defined) or data circuit-terminating equipment .(defined by ITU-T )----- constitute UNI (such as a modem), a communication network system and the link. DCE provides a physical connection to the network, and to forward traffic between DTE and DCE .provide a synchronous data transfer clock signal. contrast DTE. D channel (D channel 1) Data ----- a full duplex channel, 16Kb / s (BRA) or 64Kb / s (PRI) ISDN channel. Contrast B channel ., E channel, and H channel. 2) SNA in order to not provide any external processor and a connection between the main memory. DDP Datagram Delivery Protocol (Datagram Delivery Protocol )----- group as responsible for the AppleTalk protocol .Internet to send data through a connectionless protocol reported. DDR-demand-dial routing (dial-on-demand routing) ----- by the sending station to allow the router to be automatically begin and end a circuit-switched session technology. through .imitation remains active, the router terminals to deceive the activities of the session as a treat. DDR allows a modem or external ISDN terminal adapter ISDN or telephone lines in the routing. DE discard eligible (Discard Eligibility )----- .Frame Relay networks to tell the switch, if the switch is too busy, a frame can be discarded. DE is the frame of a field, if the committed information rate (CIR) is over-scheduled or set to 0, by the sending router open. .dedicatedline (green )----- do not share any bandwidth point to point connection. de-encapsulation (removable )----- layered protocol technology used, in which a layer from the layer protocol data unit (PDU) in .remove header information. See encapsulatio. default route (default route )----- used to guide static routing table entry frame, and its next hop is not in the dynamic routing table make clear. delay (delay) - .---- Department buried a start from the sender to the first response they receive the elapsed time between. is also a packet from its source through a path to move to the time required for their destination. See latency. demarc .(boundaries )----- customer premises equipment (CPE) with the telephone company demarcation point between carrier equipment. demodulation (modem )----- letter I prepared to return to their original form of a series of steps. reception ., the analog modem signal demodulation to the original form of the number of buildings (in turn, sent it to digital data modulated analog signal). See modulation. demultiplexing (demux )----- will be a multi-output flow .multiplexed signal composed of a single output stream back into the process. See multiplexing. designated bridge (bridge )----- specify a segment from the bridge to forward frames to the routing process, with the lowest path cost .bridge. designated port (designated port )----- and Spanning Tree Protocol (STP) to specify that the forwarding port. If a number of links to the same network, STP will shut down - a port to prevent network loops. .designated router (DR, designated router )----- as a multi-access network to create an OSPF router LSA, which is in the OSPF operation tasks for the completion of other special needs. at least two routers connected multi- .OSPF network access through the OSPF Hello protocol to select a router, which allows multi-access network only need to reduce the number of adjacent, thus reducing the factory routing of traffic and the actual size of the database. destination address (destination address )----- .receives the packet network address of the device. DHCP Dynamic Host Configuration Protocol (Dynamic Host Configuration Protocol )----- DHCP BootP protocol is a superset. This means that it uses the same protocol structure BootP, but it adds an enhanced .. When a client request, the network dynamically configure a protocol with the server client. Two major enhancement is the address pool and the lease time. dial backup (the backup dial-up connection Dial Backup )----- often used as a frame .Following connection to provide redundancy. backup link in an analog modem is activated. directed broadcast (direct broadcast )----- a data packet is transmitted to the frame or on a remote segment of a particular node group. Direct Broadcasting by .broadcast address that all bits are 1, it is a destination subnet address. discovery mode (find mode )----- also known as dynamic configuration, this technology is AppleTalk interface is used to obtain from a working node .information about attached networks. The information is then used by the interface to configure itself. distance-vector routing algorithm (distance vector routing algorithm )----- order to find the shortest path, the routing algorithm repeats a given route .the hop number, require each router sends its complete routing table updates, but only to its neighbors. This routing algorithm has generated loop trend, but more than a simple link-state algorithm. See the link-state routing al .-gorithm and SPF distribution layer (distribution layer )----- Cisco three-layer hierarchical model of the middle layer, it helps to design, install and maintain Cisco hierarchical networks. distribution layer is the access layer device connection point. .done in this layer routing. DLCI data link connection identifier (Data-Link Connection Identifier )----- frame relay network is used to identify virtual circuits. DLSw data link switching (Data Link Switching) - .---- IBM developed in 1992, data link switching (DLSw), in order to provide router-based network of SNA (System Network institutions) and NeIOS protocol support. SNA and NetBIOS is not routable protocol, does not contain .Any logical network layer 3 information. DLSw protocol encapsulated in those TCP / IP messages, these messages can be routed and a remote source route bridging (RSRB) of the options. DLSw + Cisco's DLSw implementation ---- .- In addition to supporting RFC standards, Cisco added the purpose is to increase scalability and improve performance and usability enhancements. DNS Domain Name System (Domain Name System )----- used to resolve host names to IP addresses. DSAP Destination Service Access .Fire Point (Destination Service Access Point )----- a network service access point node, the destination of the packet specified in the field. See SSAP and SAP. DSR modem ready (Data Set Ready) - .--- When the DCE is powered and ready to run, the EIA/TIA-232 interface circuit is also busy. DSU data service unit (data service unit )----- this device is used to make the data terminal equipment (DTE) institutional .The physical interface to adapt to T-1 or E-1 and the like and is responsible for signal timing transmission equipment. It is usually combined with the channel service unit together and called the CSU / DSU. See CSU. DTE data terminal equipment (data terminal equipment) - .---- no one in the user - network interface and as a destination, source or both of the client devices. DTE, including multiplexers, protocol converters and devices like computers. to a data network connection is .resulting from the use of the device clock signal data communications equipment (DCE), such as a modem formed. See DCE. UTR data terminal ready (Data Terminal Ready )----- an active communication with the DCE ETA/TIA- .232 circuit, said DTE to send or receive data has been prepared state. DUAL Diffusing Update Algorithm (Diffusing Update Algorithm )----- used in the Enhanced IGRP, this convergence of computing algorithm is provided throughout the route loop-free operation. .DUAL authorized to synchronize simultaneously involved in the topological version of the router, not with the router from the impact of this change. See Enhanced IGRP. DVMRP multicast routing from the amount of agreement between (Distance Vector Multicast Routing Protocol )---- .- mainly based on Routing Information Protocol (RTP), the Internet gateway protocol to implement a common, IP Multicast enrichment model, using TGMP transfer between its neighbors routing packets. See IGMP. DXI Data Exchange Interface (Data .Exchange Interface )----- described in RFC 1482, DXI defines a network device (such as routers, bridges, or hubs) of the effect. they complete the package with a special package DSU ATM network from a FEP role. .dynamic entries (dynamic entry )----- used at Layer 2 and Layer 3 devices dynamically create the hardware address table or logical address table. dynamic routing (dynamic routing )----- network revision. also .called "adaptive routing", the technology automatically adapts to traffic or materials buried dynamic VLAN (Dynamic DLAN )----- created in a special entry in the server manager, the server all the devices on the Internet with the hard failure .domain (domain )----- fault in the failure of the token ring area. When a station to obtain a serious failure (such as a network cable is disconnected there) information, it sends a beacon frame, including the report of the failure of the station, .It NAUN and everything between. This defines the failure domain. and then start the so-called beacon auto-configuration process. See autore configuration and the beacon. fallback (back )---- ATM network, this mechanism is used to .find a path, if it can not find a conventional method, then. The device features a relaxation of requirements (such as delay), a group trying to find a way to meet the needs of the most important path. Fast Ethernet (Fast Ethernet) .---- speed lOOMb / s Ethernet specifications. lOBaseT ten times faster than Fast Ethernet, while retaining mechanisms such as MAC, MTU and frame format of the nature of the class. These make a similar application and management of existing lOBaseT .tools can be used for Fast Ethernet network. Fast Ethernet is based on an extension of IEEE802.3 specification (IEEE 802.3U). contrast Ethemnet. See lOOBaseT, IOOBaseTX and IEEE. fast switching (use of rapid exchange )---- .route cache to speed packet switching through a router, a Cisco feature. comparative process switching. fault tolerance (fault tolerance )---- network device or communications link failure without interruption to the extent of communication. fault tolerance can be increased to a remote .auxiliary network routers. FDM Frequency Division Multiplexing (Frequency-Division Multiplexing )---- from several channels to allow the information in a line frequency allocation bandwidth access technology. See TDM, ATDM and statistical multiplexing. .FDDI Fiber Distributed Data Interface (Fiber Distributed Data Interface )---- ANSIX3T9.5 standard definition of a LAN can be up to 200Mb / s rate and the cable running to use token passing media access technology. for redundancy.