3com DUA1750-2BAA01 Manual De Usuario

3Com Switch 8800 Configuration Guide 

Chapter 35  MPLS Architecture

 

35-1 

  Note: 

A Switch 8800 running MPLS can serve as a router. Routers mentioned in this manual 

can be either a router in common sense, or a layer 3 Ethernet switch running MPLS.  

To enable MPLS function on the Switch 8800, you must select the interface cards that 

support MPLS. Note that all the B cards do not support MPLS. For example, FT48C 

card supports MPLS, but FT48B does not.  

 

MPLS (Multiprotocol Label Switching) encapsulates network layer packets with short 

and fixed-length labels. As the name implies, it supports multiple protocols, such as IP, 

IPv6, and IPX. And it allows a device to make forwarding decision based on the labels 

attached to the received packets without going through the complex routing table 

lookup procedures with IP. MPLS brings together the advantages of the connectionless 

control with IP and the connection-oriented forwarding with ATM. In addition to the 

support from IP routing and control protocols, its powerful and flexible routing functions 

allows it to accommodate to various emerging applications. 

MPLS was initially proposed to accelerate the packet forwarding on routers, but it has 

been widely used in Traffic Engineering (TE), Virtual Private Network (VPN), and other 

aspects, and is becoming one of the most important standards on large scale IP 

networks. 

Forwarding Equivalence Class (FEC) is an important concept in MPLS. MPLS is 

actually a kind of classify-and-forward technology. It categorizes packets with the same 

forwarding strategy (same destination addresses, same forwarding routes and same 

QoS levels) into one class, which is called a FEC. Generally, the FEC classification is 

based on network layer address. Packets of the same FEC are processed in the same 

way in MPLS network.