3. Introduction
• MPLS stands for Multi-Protocol Label
Switching.
• The IETF’s MPLS working group was formed
in 1997.
• Multi Protocol – indifferent towards protocol
used at Layer 2.
• Label – labels are used instead of IP addresses
for processing.
• Switching – Routing at the speed of Switching.
4. Contd…
• MPLS is an Internet Engineering Task Force
(IETF) specified framework .
• Efficient forwarding, routing & switching of
traffic flow through the network.
• Evolved from technologies such as, CISCO’s
“Tag Switching”, IBM’s “ARIS” &
TOSHIBA’s “Cell-Switched Router”.
6. MPLS Basics
• MPLS is new packet forwarding protocol.
• Works at above layer 2 & below layer 3, also
called layer 2.5.
• It uses Label Switching.
• Combines the benefit of both Circuit
Switching & Packet Switching.
9. NMC
• It plays vital role in monitoring &
controlling an MPLS network for
Redundancy & Reliability.
• NMC controls following factors:
1. LSP usage – Congestion Control
2. Label Distribution
3. Creation of VPN’s
10. MPLS Operations
1. Label PUSH : A new label is pushed on
top of the packet, effectively
encapsulating the original IP packet in a
layer of MPLS.
2. Label SWAP : Every incoming label is
replaced by a new outgoing label ( as per
path to be followed) & packet is
forwarded to next downstream LSR.
Commonly done by intermediate LSR’s
in the provider network.
11. Contd…
3. Label POP : Removes the top most label from
the label stack to prepare that packet for its
final destination i.e., de-encapsulating.
Commonly done by the egress router or by
the router preceding the egress router as
Penultimate Hop Popping.
12. MPLS Security & Costing
• Provides separation of address and traffic.
Packets from one VPN do not
inadvertently go to another VPN.
• Malicious spoofing is impossible.
• Features affecting costing
Bandwidth required
No. of MPLS ports required.
Period of hiring of ports.
Prioritized Traffic (Class of Service).
14. Limitations
• An additional layer is added.
• The Router has to understand MPLS.
15. Applications
• MPLS-based VPN
• MPLS-based Traffic Engineering
• MPLS QoS
• Route the time sensitive voice & video packets
through the low latency route throughout the
network.
