ATM edge LSR --A router that is connected to the ATM-LSR cloud through LC-ATM interfaces. The ATM edge LSR adds labels to unlabeled packets and strips labels from labeled packets.
ATM-LSR --A label switch router with a number of LC-ATM interfaces. The router forwards the cells among these interfaces using labels carried in the VPI/VCI field of the ATM cell header.
CoS --Class of service. A feature that provides scalable, differentiated types of service across an MPLS network.
IP precedence --A 3-bit value in a ToS byte used for assigning precedence to IP packets.
label --A short fixed-length label that tells switching nodes how to forward data (packets or cells).
label-controlled ATM interface (LC-ATM interface) --An interface on a router or switch that uses label distribution procedures to negotiate label VCs.
label edge router (LER) --A router that performs label imposition.
label imposition --The action of putting the first label on a packet.
label switch --A node that forwards units of data (packets or cells) on the basis of labels.
label switched path (LSP) --A sequence of hops (Router 0...Router n) in which a packet travels from R0 to Rn by means of label switching mechanisms. A label switched path can be chosen dynamically, based on normal routing mechanisms, or it can be configured manually.
label switched path (LSP) tunnel --A configured connection between two routers, in which label switching techniques are used for packet forwarding.
label switching router (LSR) --A Layer 3 router that forwards a packet based on the value of a label encapsulated in the packet.
label VC (LVC) --A n ATM virtual circuit that is set up through ATM LSR label distribution procedures.
LFIB --Label Forwarding Information Base. The data structure used by switching functions to switch labeled packets.
LIB --Label information base. A database used by an LSR to store labels learned from other LSRs, as well as labels assigned by the local LSR.
MPLS --Multiprotocol label switching. An emerging industry standard that defines support for MPLS forwarding of packets along normally routed paths (sometimes called MPLS hop-by-hop forwarding).
QoS --quality of service. A measure of performance for a transmission system that reflects its transmission quality and service availability.
tailend --The downstream, received end of a tunnel.
TDP --Tag Distribution Protocol. The protocol used to distribute label bindings to LSRs.
traffic engineering --The techniques and processes used to cause routed traffic to travel through the network on a path other than the one that could have been chosen if standard routing methods had been applied.
traffic engineering tunne l--A label-switched tunnel that is used for traffic engineering. Such a tunnel is set up through means other than normal Layer 3 routing; it is used to direct traffic over a path different from the one that Layer 3 routing could cause the tunnel to take.
VPN --Virtual Private Network. Enables IP traffic to use tunneling to travel securely over a public TCP/IP network.