H3C S10500 Series, Руководство по настройке Mpls

Страница: 209 / 400

197
Table 1 compares the implementation modes of MPLS L2VPN.
Table 1 Comparing the MPLS L2VPN implication 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
few network resources.
•
Network devices only need to support MPLS.
•
Supports QoS for traffic as LSPs are exclusive to
CCC 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, and
all the 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 the
network operation.
Disadvantage : Supports only remote connections.
Sparse Layer 2
connection,
such as a star
connection.
Kompella
VC label encapsulation :
two levels of labels
VC label distribution :
BGP
Advantages :
•
Introduces the concept of VPN, preventing 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 the network operation.
Disadvantage : The implementation is relatively
complicated.
Full-mesh
network.