Mpls : What Is Multiprotocol Label Switching
(Mpls), How Mpls Works
1. What is MultiProtocol
Label Switching (MPLS)?
Multiprotocol Label Switching (MPLS) is a mechanism in
high-performance telecommunications networks that directs
data from one network node to the next based on short path
labels rather than long network addresses, avoiding complex
lookups in a routing table. It is a mechanism used to transfer
data across large data/voice/video networks.
Each packet entering an MPLS network is labeled with
a locally significant MPLS label. As the packet passes through
the MPLS network, label is replaced with another label or
stripped off. The network distributes information so that
each switch knows what it is supposed to do if it encounters
a particular label by simply looking up the MPLS table.
Thus, the router functionality is reduced to switch functionality,
speeding up the data transfer significantly.
MPLS is a packet-forwarding technology which uses labels
to make data forwarding decisions. The biggest advantage
using MPLS is that the Layer 3 header analysis is done just
once (when the packet enters the MPLS domain). Intermediate
routers will not analyze the IP packet, thus saving valuable
router resources, and greatly increasing the speed at which
packets are forwarded. Label inspection drives subsequent
packet forwarding. Further MPLS supports following applications:
- Virtual Private Networking (VPN)
- Traffic Engineering (TE)
- Quality of Service (QoS)
- Any Transport over MPLS (AToM)
Additionally, it decreases the forwarding overhead on
the core routers. MPLS technologies are applicable to any
network layer protocol