JMF is an intermediate-level course. This two-day course is designed to provide students with a solid foundation on. Multiprotocol Label Switching (MPLS).

April 18, 2017 When you are moving up the network ladder, you might come across an opportunity to enter the MPLS world. That’s when you realize that MPLS is much different from the IP world you have dealt with so far. But the fact is that MPLS is much easier than it appears to be if you understand what the frequently used MPLS terms mean and what they do. So, if you are new to MPLS and have been trying to figure out some MPLS fundamentals, read on.

MPLS Basics IP-based Forwarding In, each router that receives a packet looks up the next hop IP address in its routing table and then forwards the packet to the next router until it reaches its destination. There are several limitations to this method, such as the lack of scalability, the need for expensive ASICs that perform IP routing lookups, lack of support for traffic engineering, the inability to support multi-service networks, and poor integration with backbone networks running Layer 2.

MPLS or Multi-Protocol Label Switching This is a switching technology that forwards data from one source to its destination using labels rather than IP addresses. With, only the first device does a routing lookup and identifies the destination and a path from the source to destination.

The router then applies a label based on this information, which is then used by the routers along the path to route traffic to the destination without the need for any IP lookups. Upon reaching the destination, the label is removed and the packet is delivered using IP routing. MPLS allows the implementation of traffic engineering, because the path is pre-determined and can work in the Layer 2 backbone as well as over IP-routing networks. Forwarding Equivalence Class (FEC) FEC is a group of packets with similar characteristics that are forwarded in the same manner over the same path and with the same forwarding treatment.

Label Edge Router (LER) This is the router where the MPLS process starts. An LER is a router that operates at the edge of an MPLS network and is the entry and exit point to the MPLS network. It is the LER that determines the path, pushes an MPLS label onto an incoming packet based on the path to be taken, and encapsulates a packet inside an MPLS Label Switched Path (LSP), defined below. Vetryanaya meljnica 2 klass tehnologiya prezentaciya. The LER can also be the “Egress Node” when it is the final router at the end of an LSP and is the exit point from the MPLS network. When acting as the Egress Node, the LER removes (pops) the MPLS label from a packet before it is forwarded over IP or the underlying network. Label Switching Router (LSR) Also known as the transit router, the LSRs are routers that lie along a label switched path established by LERs between a source and destination pair. Filmi cherez torrent menya zovut bill underwood.

The function of an LSR is to perform MPLS label switching. When an LSR receives a packet, it looks up the MPLS label on the packet and determines the next hop along the LSP.

The LSR then removes the current label and replaces (swaps) it with a new label based on the path and forwards the packet to the next LSR. Label Switched Path (LSP) This is the most basic concept of MPLS. An LSP is the pre-determined path established between two routers (LER) to route traffic in an MPLS network. An LSP is established over a sequence of LSRs based on the criteria in the FEC. It is only after an LSP has been established that MPLS forwarding can occur. LSPs are unidirectional which means that return traffic is sent over a different LSP. Label Distribution Protocol (LDP) LDP is another basic building block of an MPLS network.

LDP is used by LERs to establish a label switched path from a source to a destination. While there are multiple modes by which this is done, the common modes are downstream on demand, also known as solicited mode, and unsolicited mode. In downstream on demand or solicited mode, the upstream LER sends out an LDP label request to the next hop router determined from the routing table.