Chapter 18. Mpls; Mpls Overview - Samsung Ubigate iBG3026 Configuration Manual

Ubigate iBG3026 Configuration Guide
CHAPTER 18. MPLS

MPLS Overview

Multiple Protocol Label Switching(MPLS) is an IETF standards-based approach
built on the efforts of the various proprietary multilayer switching solutions.
In MPLS, data transmission occurs on label-switched paths(LSPs).
Forwarding Equivalent Class(FEC) determines traffic mapping into MPLS
LSPs at the ingress point of the MPLS network. Traffic flow towards
equivalent destination belongs to the same FEC.
As traffic enters the MPLS network, each packet is marked with a label.
A label, in its simplest form, identifies the path a packet should traverse.
A MPLS label is carried or encapsulated in between the Layer 2 and the Layer 3
header. The receiving router examines the packet for its label content to determine
the next hop. Once a packet has been labeled, the rest of the journey of the packet
through the backbone is based on label switching. The label values are of local
significance only, meaning that they pertain only to hops between LSRs.
L2VPN
Configuring L2VPNs in an MPLS environment allows one end node to
traverse inter-AS boundaries or even two different MPLS networks to another
end node without the network being visible. These end nodes see the
connection as an end-to-end connection rather than the multihop connection it
actually is. The following figure illustrates the benefit of an L2VPN.
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