MPLS in 3 minutes or less

Author: Jon Price

What is MPLS?

• MPLS – Muli(ple) Protocol Label Switching

• Lives at Layer 2.5

• Originally designed to speed up routing of packets in an SP cloud

Benefits of MPLS

• Scalable

• Interface independent

• Faster routing

• Private connections

Benefits of MPLS - Scalable

London Sheffield Leeds Glasgow

Edinburgh

Benefits of MPLS

London

Leeds

Glasgow

Sheffield

Edinburgh

Benefits of MPLS

MPLS

London

Leeds

Glasgow

Sheffield

Edinburgh

xDSL

Ethernet

ISDNEFM

Leased line

What is “Label Switching”?

• Traditionally each router looks “inside” the packet to determine it’s destination

• Opening the envelope at every sorting office to work out where it needs to go = SLOW!

What is “Label Switching?”

• In MPLS routers have pre-defined label-switched paths in their routing table

• They already know the best route to varying destinations

What is “Label Switching?”

• Router 1 (PE) adds a shipping label to the packet

What is “Label Switching?”

• The rest of the routers handle the packet with this label according to their LSP

What is “Label Switching?”

• The final router pops the label and delivers as normal

What is “Multiprotocol?”

MPLS

London

Leeds

Glasgow

Sheffield

Edinburgh

xDSL

Ethernet

E1EFM

Leased line

PPPoA

SONET

ISDN

Ethernet

Ethernet

Common Terminology

• PE? CE? P?

P = Provider Router (Core)

PE = Provider Edge

CE = Customer Edge

MPLS Summary

• Multiprotocol

• Label Switching

• Scalable

• Interface independent

• Faster than traditional routing

Really quick other stuff – MPLS VPN

• Switch in the cloud (L2 - VPLS)– Offers a long Ethernet cable

– VPN spanning between sites

– Time critical applications (VoIP, Video)

• L3 VPNs (VPRN)– VRFs for each customer

– CE and PE peer and exchange routes

– Complex network layout

– Needs MP-BGP

Questions?