Table of Contents

A
B
C
D
E
G
I
L
M
N
P
Q
R
S
T
U
V

glossary

A
API	Application Programming Interface. APIs are supplied as CORBA IDL files with Cisco VPN Solutions Center products. After compiling these IDL files to produce language-specific implementation files for the target language of your choosing, you can use these APIs to incorporate MPLS-VPN features in third-party client-application source code.
area	Segments and their attached devices. Areas are usually connected to other areas through routers, making up a single autonomous system. See also AS. See also region.
AS	Autonomous System. A collection of networks under a common administration sharing a common routing strategy. Autonomous systems are subdivided by areas or regions. An autonomous system must be assigned a unique 16-bit number by the IANA. Specific to BGP for MPLS VPN Solution.
ATM	Asynchronous Transfer Mode.
ATM-LSR	A label switch router with a number of LSC-ATM interfaces. The router forwards the cells among these interfaces using labels carried in the VPI/VCI field.
ATM edge LSR	A router that is connected to the ATM-LSR cloud through LSC-ATM interfaces. The ATM edge LSR adds labels to unlabeled packets and strips labels from labeled packets.
autonomous system	See AS.

B
baseline	A set of data collected from targets. For example, the latest configuration files for a list of Cisco Routers, or the latest configuration files, IP unnumbered information, and PVC information for a list of Cisco Routers. MPLS VPN Solution software automatically maintains baselines that correspond to: 1) the latest PE configuration files in the Provider Administrative Domain (with one baseline per PAD); 2) the latest configuration files of the CEs and PEs in the VPNs that the customer has defined. MPLS VPN Solution uses these baselines to create audit and topology reports.
BGP	Border Gateway Protocol. An interdomain routing protocol designed for the global Internet. Exterior border gateway protocols (EBGPs) communicate among different autonomous systems. Interior border gateway protocols (IBGPs) communicate among routers within a single autonomous system. It is defined in RFC 1163.
Border Gateway Protocol	See BGP.
border router	A router at the edge of a provider network that interfaces to another provider's border router using the EBGP protocol.

C
CAR	Committed Access Rate. CAR is Cisco's traffic policing tool for instituting a QoS policy at the edge of a network. CAR allows you to identify packets of interest for classification with or without rate limiting. CAR allows you to define a traffic contract in routed networks.
CE	Customer Edge Router. A CE is part of a customer network and connects to a provider edge router (PE). A CE can join any set of virtual private networks (VPNs). Each CE connects a customer site to a PE, obtaining the VPN service for that customer site, and belongs to exactly one customer. CE routers are not aware of associated VPNs. Each CE may have many configlets and may be configured by multiple SRVC service requests.
CEF	Cisco Express Forwarding. An advanced Layer 3 IP switching technology. CEF optimizes network performance and scalability for networks with large and dynamic traffic patterns. VPN routing and forwarding tables (VRFs) use CEF technology, therefore MPLS VPNs must be CEF-enabled.
CERC	CE routing community. A VPN can be organized into subsets called CE routing communities, or CERCs. A CERC describes how the CEs in a VPN communicate with each other. Thus, CERCs describe the logical topology of the VPN. MPLS VPN Solution can be employed to form a variety of VPN topologies between CEs by building hub and spoke or full mesh CE routing communities. CERCs are building blocks that allow you to form complex VPN topologies and CE connectivity.
Class of Service	See CoS.
configlet	Router configuration commands generated by MPLS VPN Solution that are added to the CE and PE router configuration files to enable a VPN between customer sites. A configuration fragment that can be downloaded to a CE or PE to modify its current IOS command-set configuration.
CORBA	Common Object Request Broker Architecture.
CoS	CoS refers to the methods that provide differentiated service, in which the network delivers a particular kind of service based on the class of service specified for each packet. CoS provides specific categories of service such as Gold, Silver, and Best-Effort service classes. CoS is a set of concrete device features in which a single network router treats traffic in different classes differently. CoS techniques provide a means of specifying policies to control network resource allocation in support of customer and applications requirements. The implementation of CoS techniques delivers measurable Quality of Service (QoS).
CoS profile	Represents a set of CoS configurations offered by a provider to its customer. Each CoS profile consists of a set of CoS classes that record configuration information on how traffic is shaped and policed across the PE-CE link.
CSM	Cisco Service Management System. The name of Cisco's large-picture project for service management. Many interdependent products fall within this project.
customer	Requests VPN service from a provider. Each customer may own many customer sites and may have many service request objects.
customer edge router	See CE.
customer network	A network under the control of an end customer. The VPN connects the single customer network by connecting the isolated sites.
customer site	A set of IP systems with mutual IP connectivity between them without the use of a VPN. Each customer site belongs to exactly one customer. A customer site can contain any number of CEs.

D
DLCI	Data-Link Connection Identifier. A value that specifies a private virtual circuit (PVC) or a switched virtual circuit (SVC) in a Frame Relay network.

E
EBGP	Exterior Border Gateway Protocol. EBGPs (see BGP) communicate among different network domains.

G

GRE

Generic routing encapsulation. A tunneling protocol developed by Cisco that can encapsulate a wide variety of protocol packet types inside IP tunnels, creating a virtual point-to-point link to Cisco routers at remote points over an IP internetwork. By connecting multiprotocol subnetworks in a single-protocol backbone environment, IP tunneling that uses GRE allows network expansion across a single-protocol backbone environment.

I
IANA	Internet Assigned Numbers Authority. Organization operated under the auspices of the ISOC as a part of the IAB. IANA delegates authority for IP address-space allocation and domain-name assignment to the InterNIC and other organizations. IANA also maintains a database of assigned protocol identifiers used in the TCP/IP stack, including BGP autonomous system numbers.
IBGP	Interior Border Gateway Protocol. IBGPs (see BGP) communicate among routers within a single network domain.
IDL	Interface Definition Language. Generic language for describing APIs for API servers. IDL API files must be compiled using an IDL compiler from an approved CORBA vendor to produce language-specific API files in a CORBA-supported target language. Using the generated target-language files you can add API-supported features to third-party client-application source code.
IGP	Interior Gateway Protocol. An Internet protocol used to exchange routing information within an autonomous system. Examples of common IBGPs include IGRP, OSPF, and RIP.
IPv4	Internet Protocol, version 4. A version of IP that support a 32-bit address space.
IPv6	A new version of IP that will replace IPv4. The key difference between IPv4 and IPv6 is that IPv6 supports a 128-bit address space to allow many more devices to be uniquely addressed as the Internet continues its exponential growth and expands into new types of devices such as telephones, automobiles, and so on.
IS-IS	Intermediate system-to-intermediate system. IS-IS is an OSI link-state hierarchical routing protocol in which ISs (routers) exchange routing information based on a single metric to determine network topology.
ISP	Internet Service Provider. Provider of internet access and services through single BGP autonomous system.

L
Label-switched path (LSP)	A sequence of hops (R0...Rn) in which a packet travels from R0 to Rn through label-switching mechanisms. A label-switched path can be established dynamically, based on normal routing mechanisms, or through configuration.
Label-switched path (LSP) tunnel	A configured connection between two routers in which MPLS is used to carry the packet.
L2TP	Layer 2 tunneling protocol.
loopback address	A logical interface on a Cisco router that is always "up" and does not connect to anything.
LSA	Link-state advertisement. A broadcast packet used by link-state protocols. The LSA contains information about neighbors and path costs and is used by the receiving router to maintain a routing table.

M
MCE	Management customer edge router. The network management subnet is connected to the Management CE (MCE). The MCE emulates the role of a customer edge router (CE), but the MCE is in provider space and serves as a network operations center gateway router. The MCE is part of a management site as defined in the MPLS VPN Solution software..
MIB	Management Information Base.
MPE	Management provider edge router. The Management PE (MPE) emulates the role of a PE in the provider core network. The MPE connects the MCE to the provider core network. An MPE can have a dual role as both a PE and the MPE.
MPLS	Multi protocol Label Switching. An emerging standard based on a Cisco Tag Switching technology.
MPLS VPN	Multiprotocol Label Switching virtual private network. For MPLS VPN Solution, it is a set of PEs that are connected via a common "backbone" network to supply private IP interconnectivity between two or more customer sites for a given customer. Each VPN has a set of provisioning templates and policies and can span multiple provider administrative domains (PADs). CE Routing Communities (CERCs) in a VPN break down complex topology into manageable subgroups.

N
network	In MPLS VPN Solution, a collection of targets (routers and NetFlow Collector devices) with unique names. A target can be a member of only one network. An MPLS VPN network allows a provider to partition the working space into manageable segments that are unique and do not overlap other networks.
network management subnet	Consists of the MPLS VPN Solution and Cisco IP Manager workstations on a single LAN. The MPLS VPN Solution network management subnet is required when the provider's service offering entails the management of customer edge routers (CEs). Once a CE is in a VPN, it is no longer accessible by means of conventional IPv4 routing unless one of the techniques described in this chapter is employed. The network management subnet connects directly to an MCE.
NLRI	Network layer reachability information. BGP sends routing update messages containing NLRI to describe a route and how to get there. In this context, an NLRI is a prefix. A BGP update message carries one or more NLRI prefixes and the attributes of a route for the NLRI prefixes; the route attributes include a BGP next hop gateway address, community values, and other information.

P
PAD	Provider Administrative Domain. Set of all PE devices in one BGP autonomous system. An administrative domain defined by an Internet Service Provider. The network owned by the PAD is called a backbone network. Each PAD includes a route distinguisher and route target and IP address pools. Each PAD can have any number of regions within it. If an ISP requires two AS numbers, it must consist of two provider administrative domains. Each provider administrative domain has regions that have a route distinguisher (RD), a route target (RT), and an IP address pool from which to automatically generate IP values during provisioning. Each provider administrative domain can have many regions.
PE	Provider edge router. A router at the edge of a provider network that interfaces to a customer's CE routers. All VPN processing occurs in the PE router. Each PE belongs to exactly one region of a provider administrative domain and connects to one or more customer sites. Each PE can have many VRF definitions and configlets, and each can be configured by many SRVC service requests.
permanent virtual circuit.	See PVC.
provider	A party supplying internet service for its customer. See also ISP.
Provider Administrative Domain	See PAD.
Provider edge router	See PE.
PVC	Permanent virtual circuit. This is applicable to Frame Relay and Asynchronous Transfer Mode.

Q
QoS	Quality of Service. The mechanisms that give network managers the ability to control the mix of bandwidth, delay, jitter, and packet loss in the network. QoS is not a device feature, it is an end-to-end system architecture. See also CoS.

R
RD	Route Distinguisher. A route distinguisher (RD) creates routing and forwarding tables and specifies the default route-distinguisher for a VPN. The RD is 8-byte value added to the beginning of the customer's IPv4 prefixes to change them into globally unique VPN-IPv4 prefixes. An RD is either ASN-relative, in which case it is composed of an autonomous system number and an arbitrary number, or it is IP-address-relative, in which case it is composed of an IP address and an arbitrary number. Each VPN route forwarding table (VRF) has an RD. Prefixes should use the same RD if they are associated with the same set of route targets (RTs). The community of interest association is based on the route target (RT) extended community attributes distributed with the Network Layer Reachability Information (NLRI).The RD value must be a globally unique value to avoid conflict with other prefixes.
region	A group of provider edge routers (PEs) within a single BGP autonomous system. Provider Administrative Domains are divided into regions just as customers are divided into sites. Each region belongs to exactly one provider administrative domain and can have many PEs. Regions allow a provider to employ unique IP address pools in large geographical regions. Each region is represented in the VPN Inventory Repository by a Region object.
RIP	Routing Information Protocol. The simplest Interior Gateway Protocol (IGP) in the Internet. This protocol is used to exchange routing information within an autonomous system. RIP uses hop count as its primary routing metric.
route distinguisher	See RD.
route target	See RT.
Routing Information Protocol	See RIP.
RT	Route Target. A 64-bit value by which the IOS discriminates routes for route updates in VRFs.
RTR	Response Time Reporter. Renamed to Service Assurance Agent (SA Agent).
RTT	Round-trip time. The total time required for a packet to traverse a network to its destination and back again.

S
Service Assurance Agent	Service Assurance Agent (SA Agent) provides round-trip times for various protocol: DNS, Echo, HTTP, Jitter, TCP Connect, and UDP Echo.
service level agreement	See SLA.
service provider network	A backbone network under the control of a service provider that provides transport services between customer sites.
service request VPN configuration	See SRVC.
site	A component of a VPN customer. A collection of one or more customer edge (CE) routers. Two CEs must be in the same site if they are connected outside the VPN. A site is defined by MPLS VPN Solution software as an attribute of a VPN customer.
SLA	Service Level Agreement. Service-Level Agreements (SLAs) are negotiated contracts between VPN providers and their subscribers. An SLA defines the criteria for the specific services that the subscriber expects the provider to deliver. The SLA is the only binding mechanism at the subscriber's disposal to ensure that the VPN provider delivers the services as agreed.
SRVC	Service Request VPN Configuration. Represents a PE-CE link provisioning request. A complete SRVC has a unique VRF definition and does not belong to a PRG. It can contain no more than two configlets---one for the PE and one for the CE. Each SRVC can configure a PE-CE pair and is initiated by one customer. Each SRVC can attach one PE interface to one VRF table.
SNMP	Simple Network Management Protocol.
SP	Service Provider.
static route	Route that is explicitly configured and entered into the routing table. Static routes take precedence over routes chosen by dynamic routing protocols.

T
target	Single device from which information may be collected. A target may be a router or NetFlow Collector, and so on. Any device (customer edge router, provider edge router, or NetFlow Collector) from which the MPLS VPN Solution software can collect information.
target language	CORBA-supported programming language to be generated by the IDL compiler based on the IDL API files. The generated target-language files can then be used to incorporate API-supported features in third-party client-application source code. For a complete list of CORBA-supported target languages, see the Object Modeling Group web site.
TCP	Transmission Control Protocol.
traffic engineering	The techniques and processes used to cause routed traffic to travel through the network on a path other than the one that would have been chosen if standard routing methods had been used.
traffic engineering tunnel	A label-switched path tunnel that is used for engineering traffic. It is set up through means other than normal Layer 3 routing and is used to direct traffic over a path different from the one that Layer 3 routing would cause it to take.
tunneling	Architecture providing the services necessary to implement any standard point-to-point data encapsulation scheme.

U
UDP	User Datagram Protocol.

V
virtual private network	See VPN.
VPIM	VPN Provisioning and Inventory Manager.
VPN	Virtual Private Network. A framework that provides private IP networking over a public infrastructure such as the Internet. In MPLS VPN Solution, a VPN is a set of customer sites that are configured to communicate through a VPN service. A VPN is a network in which two sites can communicate over the provider's network in a private manner; that is, no site outside the VPN can intercept their packets or inject new packets. The provider network is configured such that only one VPN's packets can be transmitted through that VPN---that is, no data can come in or out of the VPN unless it is specifically configured to allow it. There is a physical connection from the provider edge network to the customer edge network, so authentication in the conventional sense is not required.
vpnv4	Used as a keyword in commands to indicate VPN-IPv4 prefixes. These prefixes are customer VPN addresses, each of which has been made unique by the addition of an 8-byte route distinguisher (RD).
VRF	VPN Routing and Forwarding instance. The VRF is a key element in the MPLS VPN technology. VRFs exist on PEs only. A VRF is populated with VPN routes and allows multiple routing tables in a PE. One VRF is required per VPN on each PE in the VPN. The configuration information for a VPN routing and forwarding table for PEs that share a common route-target (RT) signature. A VRF consists of an IP routing table, a derived forwarding table, a set of interfaces that use the forwarding table, and a set of rules and routing protocols that determine what goes into the forwarding table. In general, a VRF includes the routing information that defines a customer VPN site that is attached to a PE router. In the VPN inventory repository, a VRF definition is a template by which to define a VRF table in a PE. A VRF definition is created automatically when an SRVC is created. Each VRF definition belongs to exactly one provider administrative domain and has a specific set of CERC memberships (RT signature). All SRVCs with the same connectivity in a VPN are added to a common VRF definition.

Posted: Fri Apr 21 11:03:33 PDT 2000
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