R3303-HP HSR6800 Routers MPLS Configuration Guide

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Table 2 Comparing MPLS L2VPN implementation modes
Mode
VC label encapsulation
and distribution
Advantages and disadvantages
Application
scenario
CCC
VC label encapsulation:
one level of label
VC label distribution:
static configuration
Advantages:
• Requires no signaling protocol and occupies
fewer network resources.
• Network devices only need to support MPLS.
• Better QoS for traffic as LSPs are exclusive to
CCC connections.
• Supports local and remote connections.
Disadvantages:
• Configuration and maintenance are
complicated. You must configure two static LSPs
in opposite directions for each CCC connection
on each P device.
• Cannot automatically adapt to network
changes.
Small-scale
network with a
simple
topology
where all
network
devices
support MPLS.
SVC
VC label encapsulation:
two levels of labels
VC label distribution:
static configuration
Advantage: Requires no signaling protocol and
occupies fewer network resources.
Disadvantage:
• Cannot automatically adapt to network
changes.
• Supports only remote connections.
Small-scale
network with a
simple
topology.
Martini
VC label encapsulation:
two levels of labels
VC label distribution: LDP
Advantages:
• On a carrier network, only PEs need to save a
few VC label to LSP mappings. The P devices do
not need to save any Layer 2 VPN information.
• To add a new VC, you only need to configure
the PEs of the VC, without interrupting network
operation.
Disadvantage: Supports only remote connections.
Sparse Layer 2
connections,
such as a star
topology.
Kompella
VC label encapsulation:
two levels of labels
VC label distribution:
BGP
Advantages:
• Introduces the concept of VPN to prevent CEs in
different VPNs from communicating with each
other.
• Uses label blocks to assign additional labels to
user VPNs for future use, greatly reducing the
VPN deployment and configuration workload
in the case of expansion.
• To add a CE to the network, you only need to
configure the PE to which the CE is connected.
The configuration workload is small and does
not interrupt network operation.
• Supports local and remote connections.
Disadvantage: The implementation is relatively
complicated.
Full-mesh
network.