Showing The Components And Leds Of The Mpls Module - Extreme Networks Alpine 3804 Hardware Manual

Figure 133: Showing the components and LEDs of the MPLS module
Service ports
Summary of Features
The MPLS module includes the following features:
• MPLS
• IP unicast forwarding (with selective longest prefix match)
• Destination-sensitive accounting
MPLS. MultiProtocol Label Switching (MPLS) is a forwarding algorithm that uses short, fixed-length
labels to make next-hop forwarding decisions for each packet in a stream.
MPLS is a technology that allows routers to make protocol-independent forwarding decisions based on
fixed-length labels. The use of MPLS labels enables routers to avoid the processing overhead of delving
deeply into each packet and performing complex route lookup operations based upon destination IP
addresses.
In an MPLS environment, incoming packets are initially assigned "labels" by a Label Edge Router
(LER). The labels allow the packets to be more efficiently handled by MPLS-capable routers at each
point along the forwarding path.
An MPLS label essentially consists of a short fixed-length value carried within each packet header and
that identifies a Forwarding Equivalence Class (FEC). The FEC tells the router how to handle the
packet. An FEC is defined to be a group of packets that are forwarded in the same manner. Examples of
FECs include an IP prefix, a host address, or a VLAN ID. The label concept in MPLS is analogous to
other connection identifiers, such as an ATM VPI/VCI or a Frame Relay DLCI.
Extreme Networks Consolidated Hardware Guide
Captive
retaining screw
Ejector/injector
handle
Module status LED
Module diagnostics LED
Network processors
and heat sinks
General Purpose Processor (GPP)
Configuring I/O Modules
PoS_002
MPLS_15
263