Transcript MPLS PPT
CCUG Meeting MPLS/L3VPN LAB What is MPLS? MPLS is a highly scalable, protocol agnostic, data-carrying mechanism. In an MPLS network, data packets are assigned labels. Packetforwarding decisions are made solely on the contents of this label, without the need to examine the packet itself. This allows one to create end-to-end circuits across any type of transport medium, using any protocol. wikipedia.org Original goals of MPLS Scalability of network layer routing Greater flexibility in delivering routing services Increased performance Simplify integration of routers with cell switching based technologies MPLS-Enabled Applications How does MPLS Work? MPLS works by prefixing packets with an MPLS header, containing one or more "labels". This is called a label stack. wikipedia.org What is a label? A label is a short, four-byte, fixed-length, locallysignificant identifier which is used to identify a Forwarding Equivalence Class (FEC). The label is imposed between the data link layer (Layer 2) header and network layer (Layer 3) header. The top of the label stack appears first in the packet, and the bottom appears last. The network layer packet immediately follows the last label in the label stack. wikipedia.org How does the Label move throughout the network? These MPLS-labeled packets are switched after a Label Lookup/Switch instead of a lookup into the IP table. The entry and exit points of an MPLS network are called Label Edge Routers (LER), or Provider Edge Routers which, respectively, push an MPLS label onto an incoming packet and pop it off the outgoing packet. wikipedia.org How does the Label move throughout the network? Routers that perform routing based only on the label are called Label Switch Routers (LSR) or Provider Routers. Labels are distributed between LERs and LSRs using the “Label Distribution Protocol” (LDP) wikipedia.org What platforms and Cisco IOS support MPLS? Cisco Series 2691, 3640, 3660, 3725, 3745, 6400-NRP-1, 6400-NRP-2SV, 6400-NSP, Catalyst 5000 with Route Switch Module (RSM), 7200, 7301, 7400, 7500, Catalyst 6500/Cisco 7600 Series with WS-SUP720-3B and WS-SUP720-3BXL, Gigabit Switch Router (GSR), Route Processor Module (RPM), Universal Broadband Router (UBR) 7200, AS5350, and IGX8400-URM all support MPLS. cisco.com Lab MPLS/L3VPN Lab Sources http://www.wikipedia.org/ http://www.cisco.com/ MPLS-Enabled Applications: Emerging Developments and New Technologies Ina Minei, Julian Lucek ISBN-10: 0470986441 ISBN-13: 978-0470986448