Nortel Multiservice Switch 7400/15000/20000 Terminology NN10600-005
Document status: Standard Document issue: 7.2S1 Document date: March 2006 Product release: PCR7.2 and up Job function: Product Fundamentals Type: NTP Language type: U.S. English Copyright © 2006 Nortel. All Rights Reserved. NORTEL, the globemark design, and the NORTEL corporate logo are trademarks of Nortel.
Contents What’s new 4 Secure shell (Ssh) on Nortel Multiservice Switch 15000 and 20000 4 Load Re-balancing on Parallel Links 4 List of terms 5 Nortel Multiservice Switch 7400/15000/20000 Terminology NN10600-005 7.2S1 Standard PCR7.
What’s new Terms that apply to the following features were added to this document: • Secure shell (Ssh) on Nortel Multiservice Switch 15000 and 20000 (page 4) • Load Re-balancing on Parallel Links (page 4) Attention: To ensure that you are using the most current version of an NTP, check the current NTP list in NN10600-000 Nortel Multiservice Switch 7400/ 15000/20000 What’s New.
List of terms 802.3 An IEEE standard defining Ethernet communications. AAL See ATM adaptation layer (AAL) (page 12). AAL1 See ATM adaptation layer type 1 (AAL1) (page 13). AAL2 See ATM adaptation layer type 2 (AAL2) (page 13). AAList See active alarm list (page 7). AAL2 channel identifier (CID) A numerical value associated with a virtual channel connection (VCC) narrowband timeslot. For non-switched trunks, the association is fixed when the VCC is established.
-6List of terms abstract syntax notation 1 (ASN.1) A complex data description language used for defining data in a machineindependent manner. ASN.1 is defined in ITU-T and ISO specifications. ACC See access call control (ACC) (page 6). acceptable routing path A path that satisfies the traffic requirements for an ATM PNNI call and for which the optimization metric is within the specified variance interval. Acceptable routing paths are used for ATM network load balancing.
-7List of terms ACR See available cell rate (ACR) (page 16). active alarm list A list of active alarms, residing on each running card, that have been raised but not yet cleared. actual shaping rate (ASR) The shaping rate that is applied to a given ATM virtual channel connection (VCC) or virtual path connection (VPC). This value is based on the traffic descriptor type parameters and the quality of service specified for the connection, and is determined through traffic shaping.
-8List of terms adjacency A relationship formed between selected neighboring routers for the purpose of exchanging routing information. Not every pair of neighboring routers becomes adjacent. adjacent network identifier (ANID) A numeric identifier assigned to an adjacent network that is directly connected to this network through at least one X.25 or X.75 gateway. ADPCM See adaptive differential pulse code modulation (ADPCM) (page 7). ADTF See allowed cell rate decrease time factor (ADTF) (page 9).
-9List of terms alarm agent An entity residing on every function processor (FP) and control processor (CP) that receives alarm events from a variety of services/applications. alarm Notification of an unusual, important, or abnormal event. An event can be degradation of service or quality of service conditions, processing errors, outof-service conditions, software errors, administrative conditions, or security violations.
- 10 List of terms alternate clock master For Nortel Multiservice Switch 7400 nodes, the bus tap in slot 0 or slot 15, which is the alternate clock signal for a backplane bus. This term can also be applied to the processor card that contains the bus tap. See also clock master (page 28). alternate mark inversion (AMI) A digital line encoding technique in which a zero is transmitted by no pulse while a one is transmitted by a pulse opposite in polarity to the previous pulse.
- 11 List of terms APC See access protocol control (APC) (page 6). APS See automatic protection switching (APS) (page 15). application Nortel Multiservice Switch software is partitioned into distinct software applications. Applications contain features that are loaded on cards to provide services. A Multiservice Switch node can run multiple software applications simultaneously. An example of an application is frame relay service. See also application version (AV) (page 11).
- 12 List of terms ASBR See autonomous system boundary router (ASBR) (page 15). ASCII See American standard code for information interchange (ASCII) (page 10). ASIC See application-specific integrated circuit (ASIC) (page 11). ASM See address space manager (ASM) (page 7). ASN.1 See abstract syntax notation 1 (ASN.1) (page 6). ASPEN See voice gateway control protocol (VGCP) (page 145). ASR See actual shaping rate (ASR) (page 7). AS weight policy See autonomous system weight policy (page 15).
- 13 List of terms ATM adaptation layer type 1 (AAL1) An AAL protocol used to transfer constant bit rate traffic such as voice and video. ATM adaptation layer type 2 (AAL2) An AAL protocol used to transfer variable bit rate traffic. ATM adaptation layer type 5 (AAL-5) An AAL protocol used to transfer variable bit rate, delay-tolerant, connectionoriented traffic that requires minimal sequencing or error detection support.
- 14 List of terms ATM IP function processor Nortel Multiservice Switch ATM node function processor that uses the Multiservice Switch queue controller (PQC) and ATM queue manager (AQM) ASICs to provide enhanced cell processing and ATM traffic management capabilities. ATM layer A layer in the B-ISDN protocol stack that transfers ATM cells. It is positioned between the physical layer and the AAL. ATM link A standards-based ATM connection.
- 15 List of terms attribute Defines the behavior or information associated with a specific component. Attributes are either operational or provisionable. See also operational attribute (page 93) and provisionable attribute (page 107). attribute type Specifies the structure of the attribute’s value (for example, decimal, hex, BCD, integer, or IP address). attribute value The current setting for an attribute. The structure of the value is dictated by the type of attribute.
- 16 List of terms availability-bit signaling The availability-bit (A-bit) signaling technique exchanges availability status between the two ends of a frame relay permanent virtual channel (PVC) connection. A-bit signaling permits each end of a PVC to determine if the remote end is ready to process data. availability message packet (AMP) An availability message packet (AMP) is a status message sent by a hunt group member to its hunt group server.
- 17 List of terms backbone router A router that has an interface to the backbone, including area border routers (ABR). A backbone router that has connections only to other backbone routers also functions as an internal router. backplane The printed circuit board into which control and function processors on a shelf are seated. The backplane serves two functions: distributes power to all processor cards on the shelf, and supports the bus that transports data and signaling between processor cards.
- 18 List of terms bandwidth-elastic connection See elastic connection (page 47). bandwidth-non-elastic connection See non-elastic connection (page 90). bandwidth management Allows both connectionless and path-oriented traffic to share the same Nortel Multiservice Switch trunk while ensuring that trunk bandwidth is not oversubscribed to by circuits carrying voice and video traffic.
- 19 List of terms 2 See backplane control system (BCS) (page 17). Be See excess burst size (Be) (page 50). bearer channel (B-channel) In ISDN connections, a 64 kbit/s digital bidirectional channel for carrying voice and data traffic. BECN See backward explicit congestion notification (BECN) (page 17). beginning of message (BOM) The first cell in a series of cells that result from segmentation of higher-layer packets or frames.
- 20 List of terms BITS See building-integrated timing supply (BITS) (page 21). bit-transparent data service (BTDS) Nortel Multiservice Switch application that transports continuous synchronous data (isochronous) that has already been subjected to some form of encoding across the network without interpretation. The continuous data stream is broken into fixed sized cells and sent through the network. block A a series of contiguous memory locations. User data is stored in a block.
- 21 List of terms BPV See bipolar violation (BPV) (page 19). break-before-make rerouting See connection recovery (page 33). BRI See basic rate interface (BRI) (page 18). BRM See backward resource management cell (BRM) (page 17). broadband inter-s interface (B-ICI) An interface between public ATM networks. broadcast To send one or more messages to multiple addresses on one or more networks. BSR See bootstrap router (BSR) (page 20). BT See burst tolerance (BT) (page 22).
- 22 List of terms bundle Grouping of one or more physical links using the formats and procedures of the multilink frame relay (MLFR) standards. The bundle operates as a logical interface function that emulates a single physical interface to the Q.922 data link layer. bundle link A multilink frame relay (MLFR) sub-component that controls operation of one of the bundle’s physical links.
- 23 List of terms BWOD See bandwidth on demand (BWOD) (page 18). cable management area One of the four divisions of the shelf. It allows orderly management of cables and acts as an exhaust duct for hot air. cache management system (CMS) A feature that allows the user to configure the IP local cache table size. CAC See connection admission control (CAC) (page 33). call Communication between two subscribers who are connected to endpoints of the network.
- 24 List of terms call server resource module (CSRM) A DPN-100 resource module that is directly connected to and provides call server functions for a Nortel Multiservice Switch network. candidate bootstrap router (C-BSR) A router configured to participate in a BSR election and acts as a BSR if elected. candidate rendezvous point (C-RP) A router configured as a potential rendezvous point for a specified range of multicast addresses. CAR See connection address resolution (CAR) (page 32).
- 25 List of terms CBC See connection bandwidth control (CBC) (page 33). CBR See constant bit rate (CBR) (page 34). C-BSR See candidate bootstrap router (C-BSR) (page 24). CC See congestion control (CC) (page 32). CCITT See Comité Consultatif International Télégraphique et Téléphonique (CCITT) (page 30). CCR See current cell rate (CCR) (page 37). CCS See common channel signaling (CCS) (page 30). CCT See call correlation tag (CCT) (page 23). CDL See component description language (CDL) (page 31).
- 26 List of terms cell A small, fixed-length data unit, with associated control header (cell header), that is transmitted across the network. Many cells can be required to carry a complete message for a customer. The ATM cell is 53 bytes long. cell delay variation (CDV) The allowable variation in time that a cell can take to travel over a virtual connection. Also, the measurable variation in the interval between ATM cells arriving at a network element.
- 27 List of terms cell switching A hardware-based switching technology in which data entering the network is broken down into one or more fixed-length cells. The cells are transported independently through the network and reassembled at the destination. cell transfer delay (CTD) The time it takes a cell to travel from one end of a virtual connection to the other.
- 28 List of terms CIDR See classless inter-domain routing (CIDR) (page 28). CIR See committed information rate (CIR) (page 30). circuit emulation service (CES) A service that converts and transports data from one circuit format to another. For example, a CES can convert DS1 circuit data to ATM cells at the ingress node for transport over an ATM network, and then reconvert the data to its original DS1 circuit format at the egress node.
- 29 List of terms CLP See cell loss priority (CLP) (page 26). CLR See cell loss ratio (CLR) (page 26). CLR alarm An alarm that is issued subsequent to an associated SET alarm when the fault condition no longer applies. These alarms have an activeListStatus value of “CLR”. cluster See Multiservice Switch cluster (page 85). cluster border node Nortel Multiservice Switch nodes that reside on a cluster boundary, connected by backbone-cluster border links to the backbone.
- 30 List of terms cold standby Applications and features that operate with a standby instance that is not synchronized with the active instance of the software. During an equipment switchover, cold standby applications incur longer outages than hot standby and warm standby applications, and all connections must be re-established. COM Continuation of message. See beginning of message (BOM) (page 19).
- 31 List of terms common part convergence sublayer (CPCS) A sublayer of the AAL-5 layer. common queuing An ATM queuing structure in which traffic from two or more connections is placed on a single queue during node congestion. Traffic is processed in round-robin fashion within the common queue. Compare with PHB (page 101). common transmit clock (CTC) mode An IMA configuration in which the same transmit clock is used for all physical links in the IMA group.
- 32 List of terms component instance When more than one of a component type exists, they are differentiated by an instance value. The instance value is information (such as a decimal or a string) appended to the component type. component model An OSI-like management model describing Nortel Multiservice Switch nodes in terms of a set of components arranged into hierarchies. Components contain attributes that are arranged in attribute groups. Components support verbs that take options.
- 33 List of terms connection admission control (CAC) A preventative ATM traffic management strategy through which Nortel Multiservice Switch nodes evaluate a connection request based on the traffic characteristics of both established connections and the requested connection. The request is accepted if the new connection does not jeopardize the QOS of established connections.
- 34 List of terms connection-oriented routing (CO) A routing service in which the path used by the frames or cells is determined when the connection is set up and remains fixed for the duration of the connection (barring network problems). Each path is set up on the nodes of that path and each packet needs a minimum of routing information.
- 35 List of terms control plane protection (CPP) An IP feature designed to protect the Nortel Multiservice Switch against certain denial of service (DoS) attacks on the control plane. This control plane can be defined as all packets that have locally destined IP addresses within a VR, VCG, RTR, or VRF address space and are terminating on the Multiservice Switch node. control processor (CP) A type of processor card optimized to support the software that performs complex, memory-intensive processes.
- 36 List of terms CPP See control plane protection (CPP) (page 35) CPCS See common part convergence sublayer (CPCS) (page 31) CPE Customer premises equipment. CPeD A control processor with external (BITS) DS1 timing support. C-plane See control plane (C-plane) (page 34). CQC See cell queue controller (CQC) (page 26). CQC function processor A type of Nortel Multiservice Switch ATM node function processor that uses a cell queue controller (CQC) ASIC.
- 37 List of terms cross-net polling The process of periodically exchanging a status message across the subnet between the two end points of a PVC. This message indicates the status of the source to the destination. CRS See call redirection server (CRS) (page 23). CS-ACELP See conjugate-structure, algebraic-code-excited linear prediction (CSACELP) (page 32). CSRM See call server resource module (CSRM) (page 24). CSS-IE See connection scope selection information element (CSS-IE) (page 33).
- 38 List of terms customer identifier (CID) The customer identifier is used in customer network management (CNM) to limit the user’s access to components that belong to the same customer identifier. A CNM operator can send commands only to components provisioned with the same CID as the operator. A CNM operator receives only data collection system (DCS) data, such as alarms, that is generated by components provisioned with the same CID as that of the operator.
- 39 List of terms data flow preservation The process of maintaining uninterrupted data flow over a sequence of potentially disruptive events. Connection preservation is implied whenever data flow is preserved. Data flow preservation does not guarantee that data is never discarded (for example, due to either congestion or error conditions). See connection preservation (page 34). data link control (DLC) An interface that provides logical link control connection services.
- 40 List of terms data path object environment A data path object environment is one of the two programming environments that are extensions of the operating system. The data path object environment supports the functions of Nortel Multiservice Switch network services, that is, functions that associate with data path processing. data service unit (DSU) A type of interface used to connect a terminal to a digital medium. In most cases, it is used in conjunction with a CSU.
- 41 List of terms DR See designated router (DR) (page 41). default gateway The gateway used to reach a destination if no other route is known or provided. Defense Network Secure Information Exchange (DNSIX) A protocol defined in RFC 1038 and RFC 1108 for passing confidential data securely over a network. delta channel (D-channel) A bidirectional channel, also known as the D-channel, used to carry call control messages and signaling information over ISDN links.
- 42 List of terms differentiated services code point A 6-bit field in an IP packet header that is used for specifying differentiated service parameters for the IP packet. Digital Private Network Signaling System No 1 (DPNSS 1) A common-channel signaling protocol intended for use between PBXs in private networks through time slot 16 of a 2.048 Mbit/s digital transmission system. Similarly, it can be used through time slot 23 of a 1.544 Mbit/s digital transmission system.
- 43 List of terms DNA See data network address (DNA) (page 39). DNSIX See Defense Network Secure Information Exchange (DNSIX) (page 41). domain See PNNI routing domain (page 103). domain-based rerouting (DBR) An ATM Forum standard protocol that enables the PNNI network to employ a rerouting mechanism that protects a connection segment within one or more local rerouting domains. double-ended accounting Accounting records are generated at both the ingress and egress ends of the connection.
- 44 List of terms DPRS See dynamic packet routing system (DPRS) (page 45). DRAM Dynamic random access memory. drop precedence (DP) Drop precedence refers to the importance of an IP packet. A drop precedence value is assigned to a packet to control its loss sensitivity relative to other packets when they are placed on the same queue. Generally, a drop precedence value of low indicates the packet is less likely to be discarded when the queue is congested.
- 45 List of terms DTL originator The first lowest-level node within the entire PNNI routing domain to build the initial DTL stack for a given connection. DTL terminator The last lowest-level node within the entire PNNI routing domain to process the connection (and thus the DTL for the connection). DTMF See dual tone multi-frequency (DTMF) (page 45) dual-bus mode A configuration in which both backplane buses are available to carry cells between operational cards.
- 46 List of terms E3 The 34.368 Mbit/s interface defined in ITU-T G.703 and G.704. E.164 The ITU-T recommended numbering plan for ISDN that includes the numbering plan for public switched telephone networks. early packet discard (EPD) EPD is a feature that applies a more stringent discard policy to the first cell of an AAL-5 frame than it does to subsequent cells. This reduces the number of incomplete frames in the network and thereby increases the throughput.
- 47 List of terms egress accounting A method of collecting information based on customer use of network resources. The information is used by the service provider to develop billing policies and quality of service parameters. As the name implies, this information is collected at the exit (egress) points of the network for each frame relay data link connection (DLC).
- 48 List of terms A class scheduler uses emission priority to determine relative importance between service classes for the purpose of determining which service class data is forwarded to the next queue. end of message (EOM) cell The last cell in a series of cells that result from segmentation of higher-layer packets or frames. The EOM cell marks the last cell in the cell series that represents one packet or frame. endpoint (EP) The software managing the subscriber access point.
- 49 List of terms cards. One-for-n FP sparing requires a sparing panel and only applies to electrical FPs (copper-based as opposed to fiber optical). See also spare card (page 125). equivalent bit rate (EBR) The bandwidth (in bit/s) that the network reserves for a FR-ATM connection. The EBR or requested bandwidth computation for each connection request determines the CAC mechanism. equivalent cell rate (ECR) The bandwidth (in cell/s) that the network reserves for a particular ATM connection.
- 50 List of terms excess burst size (Be) The amount of data (in bits) that a network agrees to transfer over a measured interval if network bandwidth is available. excess information rate (EIR) The sustainable rate of data transfer in excess of CIR that the network delivers if there is available bandwidth. It is related to excess burst (Be) and measurement interval (T) as EIR = Be/T. exit border node The node that progresses a call over an outside link.
- 51 List of terms exterior reachable address An address that a node can reach through a PNNI routing domain but that is not located in that PNNI routing domain. external address plan (EAP) An address plan that is not the Nortel Multiservice Switch internal address plan. Examples of EAPs are a DPN internal address plan and an IP address plan. external border gateway protocol (EBGP) BGP configuration in which sessions are established between routers in different autonomous systems (ASs).
- 52 List of terms fair buffer allocation (FBA) Guarantees that connections or classes receive a fair portion of the total available cell buffers in a function processor. FAS See frame alignment signal (FAS) (page 54). fast management information protocol (FMIP) The proprietary fast management information protocol (based on OSI/ASN.1 principles) implemented between a Nortel Multiservice Switch node and Nortel Multiservice Data Manager workstation, to manage the node.
- 53 List of terms FECN See forward explicit congestion notification (FECN) (page 54). file A set of related records that are treated as a unit for the purposes of storage and retrieval. file prober Software residing on the Nortel Multiservice Data Manager workstation that uses FTP to transfer accounting data from the Nortel Multiservice Switch node to the host computer. file transfer protocol (FTP) A TCP/IP protocol used to transfer files across an internet.
- 54 List of terms foreign address An address or address prefix that does not match the summary addresses provisioned on any given node. forward congestion indication (FCI) A bit in the Nortel Multiservice Switch common header set to indicate that congestion was experienced by packets travelling through the Multiservice Switch network. Congestion in the subnet and at the access is indicated by BCI/FCI bits.
- 55 List of terms frame link monitoring (FLM) Provides the ability to distinguish between physical line failure and customer premises equipment failure in the case of a system failure at the access to a Nortel Multiservice Switch frame relay node. framed protocol A set of formal rules describing how to transmit frames. HDLC framing uses a standard protocol for the sequential transmission of individual frames.
- 56 List of terms transmission facilities (high-quality digital facilities), which are affected by far fewer transmission errors. Furthermore, many functions such as sequencing flow control and retransmission are performed by end user equipment. Frame relay-to-ATM interworking function (FR-ATM IWF) A Nortel Multiservice Switch frame relay service that provides interworking functions between frame relay PVCs and ATM PVCs using AAL-5. See also, FR-ATM interworking service (page 56).
- 57 List of terms free list threshold A free list threshold is a specific number of blocks used in the determination of the congestion state of the free list. A free list can define several thresholds. As the free list size crosses each threshold, the free list enters a more severe congestion state. For example, ATM FPs define three free list thresholds.
- 58 List of terms gateway 1 See accounting gateway (page 6). 2 See DPN gateway (page 43). 3 See external gateway (EG) (page 51). 4 See FR-ATM gateway (page 56). 5 See gateway identifier (GID) (page 58). 6 See internal gateway (page 66). 7 See X.25 gateway (page 149). 8 See X.75 gateway (page 149). gateway identifier (GID) An integer that uniquely identifies an X.25 gateway or an X.75 gateway in a network. GCRA See generic cell rate algorithm (GCRA) (page 58).
- 59 List of terms agnostic, it can shape four emission priorities (EPs), and it does not have a usage parameter control (UPC) function because that is done by a different ASIC called ATLAS (on the same card). global rerouting domain In the context of the global rerouting protocol, the entire set of nodes in the PNNI network including all nodes belonging to all local rerouting domains.
- 60 List of terms hard rerouting See connection recovery (page 33). HDB3 See high-density binary 3 zero maximum encoding (HDB3) (page 60). HDLC See high-level data link control (HDLC) (page 61) HDLC mode See frame-cell trunk (page 54). HDLC-transparent data service (HTDS) A service that transports HDLC-framed data across the network without interpretation, except that interframe flags are not transmitted. The efficiency of the transmission is increased by not transmitting flags.
- 61 List of terms high-level data link control (HDLC) An ITU-TSS link layer protocol standard for point-to-point and multipoint communications. high-speed serial interface (HSSI) An EIA/TIA-613 physical layer standard. Similar to V.35 and V.11, HSSI is an interchange circuit that transfers serial data between DTE and DCE at speeds ranging from 1 Mbit/s to 52 Mbit/s. hitless CP switchover The switch of activity from the active CP to a standby CP without restarting the FPs on the shelf.
- 62 List of terms hop count The number of hops it takes for a packet to make it from a source to a destination, that is the number of nodes (routers) between a source and a destination. Each switch or router traversed by a packed is considered a hop. horizontal link A link between two logical nodes that belong to the same peer group. host computer The central controlling computer in a network of computers.
- 63 List of terms I80960 A 32-bit Intel embedded processor that is one of the processing engines of control processors and function processors. It coordinates all activity on these processor cards. IAD See Integrated Alarm Display (IAD) (page 65). IBGP See internal border gateway protocol (IBGP) (page 66). ICR See initial cell rate (ICR) (page 64). ICMP See Internet control message protocol (ICMP) (page 67). IGMP See Internet group management protocol (IGMP) (page 67).
- 64 List of terms in-band synchronization The process through which the accounting system takes a simultaneous snapshot of the accounting data at each end of the virtual circuit. This snapshot is used to generate an accounting record. incumbent segment An active connection segment that is in the process of being replaced by an alternate connection segment. independent link A single physical link used directly by the ATM layer. It is not part of an IMA group.
- 65 List of terms instance Information (such as a decimal or a string) appended to the component type. When more than one of a component type exists, they are differentiated by an instance value. instance type The data type for a component instance. The null data type is used for nonreplicated components, and the compound data type is used for multi-indexed components. instance value The actual component instance value as permitted by its type.
- 66 List of terms 2 See Telnet (page 133). 3 See local management interface (LMI) (page 75). 4 See SNMP (page 123). interior gateway protocol (IGP) An Internet protocol used to exchange routing information with an Autonomous System. interim interswitch signaling protocol (IISP) IISP provides interconnection between Nortel Multiservice Switch nodes as well as interconnection between Multiservice Switch and non-Multiservice Switch nodes (Nortel Networks-family nodes and devices from other vendors).
- 67 List of terms Internet control message protocol (ICMP) A collection of error conditions and control messages exchanged by IP modules in both hosts and gateways. Examples consist of echo requests and replies and notification of discarded datagrams. Internet group management protocol (IGMP) A protocol that is used between routers and locally attached hosts to communicate multicast group membership information.
- 68 List of terms inverse multiplexing for ATM (IMA) A feature available on Nortel Multiservice Switch nodes that supports the transparent transmission of ATM cell data over a link group. IMA transparently distributes a single stream of ATM layer cell traffic onto multiple physical links for transmission across the links, and then combines the traffic back into the original ATM layer cell sequence at the remote end.
- 69 List of terms IPSec A security feature that defines a suite of cryptographic protocols and an architecture used to protect packets at the network layer. IP tunneling A feature available on Nortel Multiservice Switch nodes that allows you to connect physically separate IP networks that share the same address space through an IP network on a different address space. IPIFR See Internet protocol interface over frame relay (IPIFR) (page 67).
- 70 List of terms JT2 A 6312 kbit/s interface defined in TTC JT-G.703. Consists of a framing structure of 789 bits made up of 98 time slots (8-bit) followed by 5 framing bits as defined in TTC JT-G704. junctor virtual circuit (JVC) A virtual circuit used to extend the subnet to the legacy data module in a Passport 4400 access unit. The JVC permits the establishment of a general virtual circuit (GVC) connection over a Multiservice Passport access network link (MPANL) service.
- 71 List of terms layer In the OSI reference model, a collection of related network processing functions that comprise one level of a hierarchy of functions. LC 1 See link controller (LC) (page 72). 2 See logical channel (LC) (page 76). LCN See logical channel number. LCo See logical connection (LCo) (page 76). LD-CELP See Low-delay code excited linear prediction (LD-CELP) (page 77). LDS See link delay synchronization (LDS) (page 73). leaf Is sometimes used interchangeably with party.
- 72 List of terms LIF See loss of IMA frame (LIF) (page 77). line 1 A dedicated private or leased facility that connects user equipment to the Nortel Multiservice Switch network. A line can be a link. 2 In SONET, a part of a connection between STS-n multiplexers. 3 In SDH, a part of a connection between STM-n multiplexers. line automatic protection switching (APS) 1 Automatic protection switching applied to SONET and SDH lines.
- 73 List of terms link delay synchronization (LDS) A circumstance in which the receiving end of an IMA link group has measured and compensated for the differential delay over a physical link. If this is the case, then the link is considered to be in link delay synchronization (LDS). link group (LG) 1 A group of links (Nortel Multiservice Switch trunks or DPN gateways) between two nodes that can share traffic between the nodes.
- 74 List of terms 2 See logical node (LN) (page 76). LNID See logical node identifier (LNID) (page 76). LNN See logical network number (LNN) (page 76). Load Re-balancing on Parallel Links When a new Private Network-Network Interface (PNNI) parallel link is added, or an existing PNNI parallel link is dropped and then recovered, the bandwidth is distributed equally across the parallel links.
- 75 List of terms local bus A 32-bit bus on a processor module joining local memory (SRAM and DRAM), boot ROM, SBIC, and the microprocessor. local domain edge node A node that has at least one inter-domain link. local domain link type In the context of the local rerouting protocol, a PNNI link can be described as an intra-domain link or an inter-domain link. local leaf Relevant to a single node in a PMP call.
- 76 List of terms logical channel (LC) A logical division of a Nortel Multiservice Switch trunk that constitutes part of a path. A logical channel is used in a single direction and is locally identified by a logical channel number. logical connection (LCo) A logical connection is an association between two endpoints in the Nortel Multiservice Switch network for the purpose of exchanging data.
- 77 List of terms logical processor type (LPT) Defines the characteristics of an LP. The LPT specifies which software needs to be loaded and provides some processor engineering parameters. long loop The ABR VS/VD scenario where FRM cells transit the node to the egress FP before the node turns them around to become BRM cells. LOS See loss of signal (LOS) (page 77).
- 78 List of terms LP See logical processor (LP) (page 76). LP instance One defined instance of a logical processor. In addition, when a spare card is available, an LP instance can be used to implement equipment sparing. LPD See late packet discard (LPD) (page 70). LPT See logical processor type (LPT) (page 77). LRB See Load Re-balancing on Parallel Links (page 74). LSA See link state advertisement (LSA) (page 73). LSR See label switching router (LSR) (page 70).
- 79 List of terms management data router (MDR) Collects surveillance data from multiple Nortel Multiservice Switch nodes and distributes it to multiple Nortel Multiservice Data Manager network operation centers. management information base (MIB) A database containing configuration and status information relating to a specific managed object or objects. Provides a description of all the components and variables within a component that a network management system can access.
- 80 List of terms MCDN See Meridian 1 ISDN Primary Rate Interface (MCDN) (page 81). MCR See minimum cell rate (MCR) (page 81). MCS See frame relay managed cut-through switching (MCS) (page 55). MDCR See minimum desired cell rate (MDCR) (page 81). MDP See Management Data Provider (MDP) (page 78). MDR See management data router (MDR) (page 79). measurement interval (T) The time interval over which rates and burst sizes are measured.
- 81 List of terms Meridian 1 ISDN Primary Rate Interface (MCDN) A common-channel signaling protocol intended for use between members of the Nortel Networks Meridian family of Private Telecommunication Network Exchanges. The signaling information is carried through time slot 16 of a 2.048 Mbit/s digital transmission system. Similarly, it is carried through time slot 23 of a 1.544 Mbit/s digital transmission system.
- 82 List of terms mixed-mode (MX) A type of function processor that incorporates ports supporting different types of optical fiber (Meridian devices only). A mixed-mode FP contains at least one port that operates in single mode and one port that operates in multimode. MLFR See multilink frame relay (MLFR) (page 83). MM See multimode (MM) (page 84). MMTC See multimedia traffic classes (MMTC) (page 84). model A way of describing Nortel Multiservice Switch nodes for management purposes.
- 83 List of terms MTU See maximum transmission unit (MTU) (page 79). mu-law Normally written as m-law. A technique for translating pulse code modulated voice into 64 kbit/s digital voice channels. m-law is used in North America, Japan, and other countries that use DS-1 function processors. See also A-law (page 9). multicast border router (MBR) A router that participates in more than one multicast domain.
- 84 List of terms multimedia traffic classes (MMTC) Subscriber options that enable you to select the traffic handling preferences from the network to meet the application requirements. MMTC handle delaysensitive multimedia traffic and minimize the delay transfer time and delay variance through the Nortel Multiservice Switch network. multimode (MM) Optical fiber that is capable of propagating light signals of two or more wavelengths (modes).
- 85 List of terms Multiservice Access Function Processor (MSA8 FP), 8-port The 8-port DS1 or E1 function processor card which provides Multiservice capability on the Multiservice Switch 7400. Multiservice Passport access network link (MPANL) A Nortel Multiservice Switch link support service designed to communicate with Passport 4400 access units. MPANL includes proprietary protocol elements derived from ITU-T X.36 (frame relay) and signaling protocols (Q.922 and Q.933).
- 86 List of terms Multiservice Switch trunk over ATM The transport mechanism used by Nortel Multiservice Switch trunks to carry cell traffic on an ATM-based interface. Multiservice Switch trunking system The software system that implements Nortel Multiservice Switch trunking functions, such as managing links with other Multiservice Switch nodes or DPN-100 modules. MVP-E See multipurpose voice platform enhanced echo cancellation (MVP-E) (page 84). MX See mixed-mode (MX) (page 82).
- 87 List of terms NEBS See Network Equipment Building System (NEBS) (page 87). NEP See nailed-up endpoint (NEP) (page 86). Network Clock Synchronization (NCS) System A system used to synchronize the clocking of multiple ports and nodes in the Nortel Multiservice Switch network. NCS can be synchronized to the signal originating from a single internal source or to a source external to the network. NCS ensures the accurate transmission and reproduction of synchronous data (for example, BTDS uses NCS).
- 88 List of terms network interworking function (NIWF) The FR-ATM network interworking function (NIWF) enables frame relay CPE connectivity across frame relay networks interconnected over a backbone ATM network. The NIWF encapsulates frame relay traffic over ATM and multiplexes many frame relay DLCIs to one ATM VCC. The FR-ATM network interworking function is based on the FRF.5 standard. See also, FR-ATM interworking service (page 56).
- 89 List of terms Network Time Synchronization (NTS) System A system that maintains time-of-day synchronization for all devices in the Nortel Multiservice Switch network. NTS resides in the control processor software and synchronizes the local real-time clock interface module from an IP-reachable network management system time server connection. NTS also accepts local operator commands for setting the local time.
- 90 List of terms nodal state parameter Information that captures an aspect or property of a node. node ID A unique number used to identify a specific Nortel Multiservice Switch node within a network. See NN10600-060 Nortel Multiservice Switch 7400/15000/ 20000 Component Reference for more information.
- 91 List of terms non-real time variable bit rate (NRT-VBR) A QOS class that defines the throughput connection history as bursty with an expected low cell loss ratio (CLR) for transmitted cells. NRT-VBR supports statistical multiplexing for connections, with no associated delay bounds. NRTVBR is designed to support non-real time applications. non-operational card A processor card that cannot provide service. The card can be absent, unprovisioned, locked, or has not yet finished loading its software.
- 92 List of terms NTP See network time protocol (NTP) (page 88). NTS See Network Time Synchronization (NTS) System (page 89). numbering-plan indicator (NPI) The part of a given data network address that defines the numbering plan to which it belongs. Examples of numbering plans defined by ITU-T are X.121 and E.164. OAM See operations, administration, and maintenance (OAM) (page 93). OC-3 Optical carrier level 3.
- 93 List of terms Open Systems Interconnection (OSI) A suite of communication protocols, network architectures, and network management standards produced by the International Standards Organization (ISO). The aim of OSI is to provide information transfer in a nonproprietary environment. The protocols are open in nature, that is, defined in an agreed forum by vendors and government committees.
- 94 List of terms option An option modifies the behavior or provides more information about a verb being applied to a component. For example, the display -p option shows provisioned data and the display -o option shows operational data. option type The data type of an option. option value The entered value for an option, as permitted by its type. OSI See Open Systems Interconnection (OSI) (page 93). OSI state Nortel Multiservice Switch systems define component states according to the OSI standards.
- 95 List of terms P See “provider nodes (P)” (page 107). P-node See “provider nodes (P)” (page 107). P’ Provider node within the Carrier’s Carrier domain. PA See path administrator (PA) (page 97). PABX See private branch exchange (PBX) (page 105). packet Packet is a term that can be used interchangeably with frame to mean a variable-length data unit. The term frame means a generic variable-length data unit. Packets are generally used in layer 3 and frames in layer 2.
- 96 List of terms Packet over SONET When POS is supported, the generic queue manager (GQM) function processor (FP) cards of a Nortel Multiservice Switch 7400, Multiservice Switch 15000, or Multiservice Switch 20000 nodes transmit or receive packets over SONET (POS), or over SDH. POS handles whatever the packetbased data is because it is a layer 3 protocol over a layer 1 transmission with no layer 2.
- 97 List of terms Passport 4400 A low-cost Nortel Multiservice Switch network access unit capable of multiplexing voice, fax, video, and LAN traffic onto a frame relay interface. Passport Carrier Release (PCR) The Passport Carrier Release (PCR) is the software load that runs on these members of the Nortel Multiservice Switch family: • Multiservice Switch 7400 series • Multiservice Switch 15000 • Multiservice Switch 15000 VSS • Multiservice Switch 20000 One load supports all of these nodes.
- 98 List of terms path bumping Path bumping is the forced rerouting of an existing path by a new higher priority path of another logical connection. Bumping happens when there is not enough bandwidth in the selected Nortel Multiservice Switch trunk to establish a new path. The rerouting can in turn cause bumping of other paths. A bumped path can be rerouted on another Multiservice Switch trunk if the route selection criteria of the path are satisfied.
- 99 List of terms P-SPVC See permanent switched permanent virtual circuit (P-SPVC) (page 100). P-switched permanent virtual circuit (P-SPVC) See permanent switched permanent virtual circuit (P-SPVC) (page 100). PBX See private branch exchange (PBX) (page 105). PCM See pulse code modulation (PCM) (page 109). PCR See peak cell rate (PCR) (page 100) or Passport Carrier Release (PCR) (page 97). PCS See processor control system (PCS) (page 106). PDU See protocol data unit (PDU) (page 107).
- 100 List of terms peak cell rate (PCR) The maximum transfer rate into a network, defined as upper bound on the inverse of the time interval between two consecutive ATM cell emissions. peer database exchange protocol A protocol between two neighboring ATM nodes to synchronize their topology databases over an RCC channel. peer group A set of logical nodes that the network engineer groups together for the purposes of creating a routing hierarchy. All members of the group exchange PTSEs.
- 101 List of terms permanent virtual channel (PVC) The ATM name for permanent virtual circuit. See permanent virtual circuit (PVC) (page 101). permanent virtual circuit (PVC) 1 In a frame relay network, a type of virtual circuit (VC) whose endpoints must be configured by the network operator. It is a logical connection that, once established, remains in place even when it is not being used. In ATM networking, PVC is known as a permanent virtual channel.
- 102 List of terms physical link Single physical interface that interconnects two devices in a network. PID See process identifier (PID) (page 105). PIM See protocol independent multicast-sparse mode (PIM-SM) (page 107). ping The ping command is a debugging method used to determine the reachability of another node, the path(s) to another node, and the round trip delay to another node.
- 103 List of terms PNNI routing domain A group of topologically contiguous systems that are running one instance of PNNI routing. PNNI topology state element A collection of PNNI information that is flooded among all logical nodes within a peer group. PNNI topology state packet A type of PNNI routing packet that is used for flooding PTSEs among logical nodes within a peer group. PMS See port management system (PMS) (page 104). pools See bandwidth pools (page 18).
- 104 List of terms port-VLAN identifier (PVID) The port-VLAN identifier (PVID) represents the default VLAN identifier in VLAN mode that treats untagged, priority tagged, and PVID tagged traffic. The PVID on Nortel Multiservice Switch nodes is always set to a value of 1. port management system (PMS) A software system that controls and monitors the physical interfaces that are supported on function processors. power converter Converts primary power inputs into secondary operating voltages.
- 105 List of terms primary rate interface (PRI) An integrated services digital network (ISDN) interface standard that is designated in North America as having a 23B+D channels. All circuit-switched B channels and D channels operate at 64 kb/s. priority field A 32-bit (p-bit) field in the TCI sub-header of the IEEE 802.1Q tag header. This field represents the user priority of an Ethernet packet.
- 106 List of terms processor card section The section of the shelf assembly that contains processor cards and the backplane that allows the processor cards to communicate with each other. processor control system (PCS) Nortel Multiservice Switch subsystem responsible for managing the processor cards. PCS detects when a processor becomes available for service, maps the appropriate LP to execute on it, loads its software, and monitors its execution to detect any outage that occurs.
- 107 List of terms protocol data unit (PDU) A unit or a packet of information exchanged between peer entities in a particular protocol stack. The PDU is typically submitted to the next lower (server) layer for transfer to its peer and can contain an embedded PDU of the next higher (client) layer. protocol independent multicast-sparse mode (PIM-SM) A protocol for routing multicast traffic to sparsely populated receivers that supports scalable multicast routing, independent of any unicast routing protocol.
- 108 List of terms provisioning data The data that is entered to configure Nortel Multiservice Switch modules. In other systems, it has been known as service data, configuration data, or tables. provisioning journaling Represents the journaling of configuration changes on the disk.
- 109 List of terms pulse code modulation (PCM) A standardized method of producing digital speech. Defined in ITU-T G.711. PVC 1 See permanent virtual channel (PVC) (page 101). 2 See permanent virtual circuit (PVC) (page 101). PVG See packet voice gateway (PVG) (page 96). PVID See port-VLAN identifier (PVID) (page 104). PVP See permanent virtual path (PVP) (page 101). Q interface signaling (QSIG) An internationally defined inter-PBX signaling standard.
- 110 List of terms queue A linked list of buffers that stores user or control data that is incoming or outgoing from a processor card. The data can be in the form of frames or cells. queue length The number of blocks that currently make up the queue. queue limit The maximum number of blocks that can be attained by the queue length. queue threshold A specific number of blocks used in the determination of the congestion state of the queue. A queue can define several thresholds.
- 111 List of terms reachability spanning tree A collection of PNNI nodes that are reachable from the local PNNI node. reachable NSAP address The subcomponents address (provisioned under the Trk component) and summaryAddress (provisioned under the Rtg component) that are broadcast and stored in the Base Routing Topology Database. They are also referred to as reachable addresses. See NN10600-435 Nortel Multiservice Switch 7400/ 15000/20000 Operations: Path-Oriented Routing System for more information.
- 112 List of terms remote alarm indication (RAI) On DS1, DS3, E1, and E3 interfaces, a signal transmitted in the outgoing direction when the interface determines that specific defects have persisted long enough to declare a received signal failure. remote defect indication (RDI) A signal transmitted in the upstream direction when a downstream fault is detected. The RDI signal is used at the physical and the ATM layer. remote group The remoteGroup component allows the X.
- 113 List of terms requested shaping rate (RSR) One of a set of ATM traffic characterization values used to define traffic characteristics through the traffic descriptor types. RSR defines the traffic shaping rate that is requested for a connection. This parameter is optional. If defined, the requested rate is used as a basis for determining the actual shaping rate; if not defined, traffic shaping is determined by the PCR and SCR rates defined for the connection through the traffic descriptor type.
- 114 List of terms resource module (RM) A DPN-100 network backbone device. Resource modules can also serve as call server resource modules (CSRM). resource reservation protocol (RSVP) The primary protocol used for resource reservation in IP networks. response Information generated by a component either as a result of some verb being applied to it or asynchronously to signal some event such as an alarm. A response can contain several response attributes.
- 115 List of terms RID subnet A group of interconnected Nortel Multiservice Switch nodes that share a routing identifier (RID). RIP See routing information protocol (RIP) (page 116). RM 1 See resource module (RM) (page 114). 2 See resource management (RM) cell (page 113). root node The root node of an ATM PMP call represents the first point of entry into the network for the PMP call. As a result, this node contains the root of the multicast tree.
- 116 List of terms routing class of service (RCOS) A set of parameters that describes how a frame is treated while it is being routed. Examples of these parameters are: priority, reliability, delay, and throughput. routing computation The process of applying a mathematical algorithm to a topology database to compute routes. Many types of routing computations can be used. The Dijkstra algorithm is one particular example of a possible routing computation.
- 117 List of terms RSI See Remote Server Interface (page 112). RSR See requested shaping rate (RSR) (page 113). RSVP See resource reservation protocol (RSVP) (page 114). RTD See round trip delay (RTD) (page 115). rtVBR See real time variable bit rate (rt-VBR) (page 111). S/D See source/destination (page 124). SA See security association (SA) (page 118). SAD 1 See speech activity detection (SAD) (page 126). 2 See also security association database (SAD) (page 118).
- 118 List of terms SCR See sustainable cell rate (SCR) (page 129). SCS See software control system (SCS) (page 124). SDS See software distribution site (SDS) (page 124). SDH See synchronous digital hierarchy (SDH) (page 131). SDU See service data unit (SDU) (page 119). SEC SDH Equipment Clock. secondary control bus (SCB) The secondary control buses enable the processor cards to communicate with the software embedded on any fabric card.
- 119 List of terms security policy database (SPD) A database containing all of the policies that define the security protocols for all IP traffic flows in and out of a peer. segmentation and reassembly (SAR) sublayer A sublayer of an AAL that performs segmentation of the higher-layer PDUs into ATM cell payloads and receives ATM cell payloads to be reassembled into higher-layer PDUs.
- 120 List of terms serving capacity One of the traffic parameters used by the CAC algorithm to determine if the link of the particular node can accommodate a VCC or a VPC connection point. SET alarm An alarm that is issued when a fault condition is detected. These alarms have an activeListStatus value of “SET”. SETS See synchronous equipment timing source (SETS) (page 131).
- 121 List of terms shared bus interface controller (SBIC) An ASIC used to manage and manipulate queues and blocks within the shared memory and to coordinate all direct memory access (DMA) into the shared memory. The queue controller (QC) is part of the SBIC. shared memory A common memory pool on a processor card in which all blocks, buffers, and queues are stored. Frames enter Nortel Multiservice Switch nodes from a network link to the interfacing function processor where they are stored in memory.
- 122 List of terms signal processing module (SPM) A hardware module on the voice services function processor that processes signaling information. simple network management protocol (SNMP) A multivendor standard network management protocol that polls components in the network, typically over an IP-based network. The protocol data units are encoded in ASN.1. SNMP concentrates primarily on the observation and control of the network. It is defined by RFC 1157 and RFC 1213.
- 123 List of terms SIWF See service interworking function (SIWF) (page 119). SM See single-mode (SM) (page 122). Small form-factor pluggable optical transceiver module The small form-factor pluggable (SFP) optical transceiver module is a fiber optical unit that interfaces between each optical module socket (port) on the faceplate of a function processor (FP) card and the fiber optical cables with LC small form connectors.
- 124 List of terms soft permanent virtual path (SPVP, soft PVP) Soft PVPs support the same functionality as a permanent virtual path but eliminate the need to manually provision each node along the connection. The endpoint is provisioned but the connection route is selected automatically. software control system (SCS) The software system that manages the software installed in a shelf.
- 125 List of terms SPT See shortest path tree (SPT) (page 121).
- 126 List of terms specified path connection A connection that is created using a specified path. speech activity detection (SAD) A function performed by Nortel Multiservice Switch system when processing voice calls that saves bandwidth by not transmitting the silent portions of a conversation. Typical telephone conversations consist of 40 to 60 percent silence. SPF See shortest path first (SPF) (page 121). SPI See security parameter index (SPI) (page 118).
- 127 List of terms stability timer This timer allows the detection of repetitive main FP card failures and is used to cause a switchover if a main function processor in a one-for-n sparing configuration fails within one hour after it starts running as the active FP. See also sparing timer (page 125) standard virtual path terminator A type of virtual path terminator that allows simultaneous traffic management at both the VP and VC level.
- 128 List of terms static route A static IP route is a provisioned IP route.
- 129 List of terms subcomponent A component hierarchically named within another (for example, lp/0 v35/0 is a subcomponent of lp/0). subnet mask A method for identifying the subnet field from the host field of an address. This divides a network into smaller administrative units called subnetworks or subnets. successive SET alarm A SET alarm received while there is an outstanding SET alarm against the same NTP index and component name.
- 130 List of terms A configured SPVC that uses the switched connection between networks is a permanent SPVC (P-SPVC). The switched connection at the NNI that enables connectivity between networks is a switched SPVC (S-SPVC).
- 131 List of terms switched virtual path (SVP) 1 A type of virtual path (VP) that is established and torn down by subscriber applications on an as-needed basis. It is a logical connection that remains in place only for the duration of data transfer. User equipment signals the desired destination, and the connection route is selected automatically through SVP signaling. 2 See also virtual path (VP) (page 142).
- 132 List of terms T4 Timing towards a 2 MHz (or 2 Mbit/s, no payload) synchronization interface. tag control information (TCI) Tag control information (TCI) is a subheader of the IEEE 802.1Q tag header. It consists of two octets encoded with user-priority bits, a canonical format indicator field, and a VLAN identifier. tag protocol identifier (TPID) Tag protocol identifier (TPID) is a subheader of the IEEE 802.1Q tag header. It consists of two octets encoded with the 802.1Q tag type for VLANs.
- 133 List of terms TDT See traffic descriptor type (TDT) (page 135). Telnet A terminal access protocol for accessing remote devices over an IP-based network. The protocol provides support for various types of terminals and is typically found in IP- or UNIX-based environments. To establish a Telnet connection, you need both a Telnet client and a Telnet server. The Telnet client resides on the local device and connects to the Telnet server on the remote device.
- 134 List of terms timer-mode accounting When TODA is disabled, an accounting record is generated every 12 hours for each connection. TM See traffic management (TM) (page 135). TMS See Time Management System (TMS) (page 133). TODA See time-of-day accounting (TODA) (page 133). topology maintenance A software system that performs network topology discovery and maintenance for the Nortel Multiservice Switch node.
- 135 List of terms trace destination interface The interface on which a path or connection trace terminates when it completes normally. trace destination node The node that terminates the path or connection trace for a given connection and has an outgoing trace destination interface. trace source interface The interface at the trace source node that is designated as the starting point for the path or connection trace of a given connection.
- 136 List of terms transit network An OSPF network with more than one router. transit node A logical representation of a node, which is also known as a hop node. It is composed of an address called node ID and an egress port called port ID. translation mode One of two modes of the FR-ATM interworking service. When translation mode is chosen for a PVC, the FR-ATM interworking function performs the mapping of upper layer protocol encapsulations between the two incompatible encapsulation methods.
- 137 List of terms trivial file transfer protocol (TFTP) A protocol that governs transferring files between nodes without protection against packet loss. trunk The generic term for a physical connection, not a Nortel Multiservice Switch network-specific term. trunk conditioning (TC) A technique whereby a constant bit pattern is applied to specific time slots to indicate downstream that the system has detected a fault in the upstream data path.
- 138 List of terms UBR with MDCR See unspecified bit rate (UBR) with minimum desired cell rate (MDCR) (page 138). UDP See user datagram protocol (UDP) (page 139). UMTS See Universal Mobile Telecommunications System (page 138). UNI See user-to-network interface (UNI) (page 139). UNI scope The membership scope associated with group addresses. unicast forwarding A packet forwarding mode that delivers the packet to a single destination (egress node).
- 139 List of terms uplink An uplink is a logical link representing the connectivity from a border node to an upnode. Uplinks are the basis for horizontal links between nodes. upnode An upnode is the node that represents a border nodes’s outside neighbor in the common peer group. It must be a neighboring peer of one of the border node’s ancestors. usage parameter control (UPC) A traffic management strategy that enforces traffic characteristics at network access points.
- 140 List of terms V5.2 An interface specification defined in the ETSI EN 300 324-1 and ETSI EN 300 347-1 standards. A V5.2 interface connects a local exchange in a PSTN network to a number of remote end users. variable The field in a component name that can be used to store an attribute. The attribute denotes the external representation of a variable. A variable is the internal representation of an attribute.
- 141 List of terms verb The command or action to be applied to a component. Verbs take options and produce responses. For example, the delete verb removes a component from the edit view. VID See VLAN identifier (VID) (page 145). view A database used to store provisioning data. The current view contains the current data. The edit view contains data used to edit the current view. The committed view contains information used in case of a restart or reset.
- 142 List of terms virtual circuit (VC), frame relay networking In frame relay networking, the equivalent of a physical connection to a destination address using shared facilities. Virtual circuits can be permanent (PVC) or switched (SVC). The virtual circuit is anchored in the function processors that are connected to the end user devices. Virtual Circuit System (VCS) The software system that allows Nortel Multiservice Switch networks to offer virtual circuits.
- 143 List of terms In ATM networking, a unidirectional transport of ATM cells belonging to virtual channels that are associated by a common identifier value called VPI. virtual path connection (VPC) A logical association among, or a group of, virtual channels that have the same traffic characteristics and follow the same path in a network.
- 144 List of terms virtual router redundancy protocol (VRRP) A protocol that specifies an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. virtual router redundancy protocol backup (VRRP backup) The set of VRRP routers available to assume forwarding responsibilities for a virtual router should the current master router fail.
- 145 List of terms VLAN identifier (VID) A VLAN identifier (VID) is a 12-bit field in the TCI subheader of the IEEE802.1Q tag header. VM See Virtual Media (VM) (page 142). voice band data (VBD) Modulated data calls, typically fax and modem calls, carried on a voice connection. voice compression The process of electronically modifying a 64-kbit/s voice channel to obtain a channel of 32 kbit/s or less for the purpose of increased efficiency in transmission.
- 146 List of terms voice processing module (VPM) A hardware module on the voice services function processor that processes voice and voice band data. voice profile (VP) A collection of parameters used in voice networking SVC establishment to define the quality of service for a particular call, depending on the dialed number. voice service Voice service allows you to interconnect voice switches, such as PBXs.
- 147 List of terms VPN extender (VpnXc) A special server card that increases the scalability of IP VPN services. It has its own dedicated processor and memory and acts as the IP VPN control plane, hosting all IP VPN virtual routers. VpnXc See VPN extender (VpnXc) (page 147). VPT See virtual path terminator (VPT) (page 143). VPT-CAC See virtual path termination CAC (VPT-CAC) (page 143). VR See virtual router (VR) (page 143). VRAP See virtual router access point (VRAP) (page 143).
- 148 List of terms VTDS Voice transparent data service. See transparent data service (TDS) (page 136). VUNI See virtual interface (page 142). waiting delay The time a frame or cell waits in a transmission queue before it gets transmitted. WAN See wide area network (WAN) (page 148). warm standby Warm standby applications reduce service outages during an FP or CP switchover.
- 149 List of terms wild-carded binary-coded decimal (BCD) The binary-coded decimal data type with the addition of the ? character to represent any possible value. wildcard pattern A wildcard pattern consists of a character string, with one or more wildcard (*) characters, where * matches zero or more characters. wildcarding Using the asterisk (*) wildcard character or a wildcard pattern to match more than one component.
- 150 List of terms XNTP A Nortel Multiservice Switch system feature that controls the setting of network time. xPD A generic term for any of a number of packet discard algorithms (for example, EPD, PPD, WRED). Y-Protection A Y-protection configuration enables two matched fiber optical FPs to have hitless equipment protection (EP) and hitless software migration (HSM) while the far-end interface does not support automatic protection switching (APS) or multiplex section protection (MSP).
Nortel Multiservice Switch 7400/15000/20000 Terminology Copyright © 2006 Nortel. All Rights Reserved. Publication: NN10600-005 Document status: Standard Document issue: 7.2S1 Document date: March 2006 Product release: PCR7.2 and up Job function: Product Fundamentals Type: NTP Language type: U.S. English NORTEL, the globemark design, and the NORTEL corporate logo are trademarks of Nortel.
