CE router --customer edge router. A router that is part of a customer's network and interfaces to a provider edge (PE) router.
customer network --A network that is under the control of an end customer. Private addresses can be used in a customer network. Customer networks are logically isolated from each other and from the service provider's network.
edge router --A router at the edge of the network that receives and transmits packets. It can define the boundaries of the Multiprotocol Label Switching (MPLS) network.
headend --The label switch router (LSR) where a tunnel originates. The tunnel's "head" or tunnel interface resides at this LSR as well.
label --A short, fixed-length data construct that tells switching nodes how to forward data (packets).
label switched path (LSP) tunnel --A configured connection between two routers in which label switching is used to carry the packets.
LSP --label switched path. A path that a labeled packet follows over several hops, starting at an ingress LSR and ending at an egress LSR.
LSR --label switch router. A Layer 3 router that forwards a packet based on the value of a label encapsulated in the packet.
mesh group --A set of label switch routers (LSRs) that are members of a full or partial network of traffic engineering (TE) label switched paths (LSPs).
P router --provider core router.
PE router --provider edge router. A router at the edge of the service provider's network that interfaces to customer edge (CE) routers.
router --A network layer device that uses one or more metrics to determine the optimal path along which network traffic should be forwarded. Routers forward packets from one network to another based on network layer information.
tailend --The downstream, receive end of a tunnel.
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.
tunnel --A secure communication path between two peers, such as two routers. A traffic engineering tunnel is a label switched tunnel that is used for traffic engineering. Such a tunnel is set up through means other than normal Layer 3 routing.