Multi-Protocol Label Switching - Traffic Engineering Sample Clauses

Multi-Protocol Label Switching - Traffic Engineering. In larger IP-networks, e.g. those owned by ISPs, MPLS is a widely deployed technol- ogy [▇▇▇▇▇▇▇▇▇ and ▇▇▇▇▇▇▇▇▇, 2011, pp.488–492]. When an IP-packet enters the MPLS domain, a Label Edge Router (LER) inspects the IP-packet to determine the destination, and then adds a label to the packet, by encapsulating it in a separate header. The label is then used at the next hop within the MPLS domain, i.e. the Label Switched Router (LSR), to determine the further path of the packet. When the packet reaches the other edge of the MPLS domain, the label header is popped of and the packet is forwarded to the next network. Using labels to determine packet routes, simplifies the switching process to a table lookup with the label as index, hence it is relatively simple and thereby also fast. Furthermore, this pushes the complexity of traffic classification to the edges of the network, making the core simple and effective. The packet routes are identified using labels and therefore also referred to as LSPs, which are set up using upper layer control protocols. Commonly, MPLS routers aggregate flows into different groups, each called a Forwarding Equivalence Class (FEC). These map to a specific label, thus the FECs can be compared to the service classes in DiffServ. With MPLS as the basic network technology, several network protocols, have been ex- tended to also provide mechanisms for Traffic Engineering (TE). One of them is RSVP- TE, where the traffic engineering functionalities allows LSPs to be set up, according to available bandwidth on the links in the MPLS domain. This allocates resources through-