cross-connect (XC) —An association of in-segments and incoming MPLS interfaces to out-segments and outgoing MPLS interfaces.
FPI —forwarding path identifier. An identifier required to locate MPLS forwarding information for a FEC. Examples of types of FPIs supported by the MPLS Forwarding Infrastructure (MFI) are IPv4, IPv6, LABEL, SSS, and TE.
IETF —Internet Engineering Task Force. A task force (consisting of more that 80 working groups) that is developing standards for the Internet and the IP suite of protocols.
inSegment —A label on an incoming packet that is used to determine the forwarding of the packet.
label —A short, fixed-length identifier that is used to determine the forwarding of a packet.
label switching —A term used to describe the forwarding of IP (or other network layer) packets using a label swapping algorithm based on network layer routing algorithms. The forwarding of these packets uses the exact match algorithm and rewrites the label.
LDP —Label Distribution Protocol. A standard protocol between MPLS-enabled routers that is used for the negotiation of the labels (addresses) used to forward packets.
LFIB —Label Forwarding Information Base. A data structure and way of managing forwarding in which destinations and incoming labels are associated with outgoing interfaces and labels.
LSP —label switched path. A sequence of hops in which a packet travels from one router to another router by means of label switching mechanisms. A label-switched path can be established dynamically, based on normal routing mechanisms, or through configuration.
LSR —label switching router. A device that forwards MPLS packets based on the value of a fixed-length label encapsulated in each packet.
MFI —MPLS Forwarding Infrastructure. In the Cisco MPLS subsystem, the data structure for storing information about incoming and outgoing labels and associated equivalent packets suitable for labeling.
MIB —Management Information Base. Database of network management information that is used and maintained by a network management protocol such as SNMP. The value of a MIB object can be changed or retrieved by means of SNMP commands, usually through a network management system. MIB objects are organized in a tree structure that includes public (standard) and private (proprietary) branches.
MOI —MPLS output information. The MOI includes the next hop, outgoing interface, and outgoing label.
MPLS —Multiprotocol Label Switching. MPLS is a method for forwarding packets (frames) through a network. It enables routers at the edge of a network to apply labels to packets (frames). ATM switches or existing routers in the network core can switch packets according to the labels with minimal lookup overhead.
MPLS interface —An interface on which MPLS traffic is enabled.
NMS —Network Management Station. A device (usually a workstation) that performs SNMP queries to the SNMP agent of a managed device in order to retrieve or modify information.
notification request —Message sent by an SNMP agent to a network management station, console, or terminal, indicating that a significant event occurred. SNMP notification requests are more reliable than traps, because a notification request from an SNMP agent requires that the SNMP manager acknowledge receipt of the notification request. The manager replies with an SNMP response protocol data unit (PDU). If the manager does not receive a notification message from an SNMP agent, it does not send a response. If the sender (SNMP agent) never receives a response, the notification request can be sent again. Thus, a notification request is more likely than a trap to reach its intended destination.
outSegment —A label on an outgoing packet.
SNMP —Simple Network Management Protocol. Management protocol used almost exclusively in TCP/IP networks. SNMP provides a means for monitoring and controlling network devices, and for managing configurations, statistics collection, performance, and security.
trap —Message sent by an SNMP agent to a network management station, console, or terminal, indicating that a significant event occurred. Traps are less reliable than notification requests, because the receiver does not send an acknowledgment when it receives a trap. The sender cannot determine if the trap was received.