3Com S7902E, Руководство по настройке

Страница: 1143 / 2621

1-3
instances that are running on PE1: the public instance, VPN instance A, and VPN instance B. These
three instances can be regarded as three independent virtual devices, which are PE 1’, PE 1”, and PE
1’”, each virtual device corresponding to a plane.
Figure 1-2 Multicast in multiple VPN instances
Site 6
Site 4
Site 2
Site 5
Site 3
Site 1
VPN instance A
VPN instance B
Public instance
MD B
MD A
PIM
PE 1"
PE 1"'
PE 2"
PE 2"'
PE 3"'
PE 3"
P
PE 1' PE 2'
PE 3'
With multicast VPN, when a multicast source in VPN A sends a multicast stream to a multicast group, of
all possible receivers on the network for that group, only those belong to VPN A, namely in Site 1, Site 3
or Site 5, can receive the multicast stream. The stream is multicast in these sites and in the public
network.
The prerequisites for implementing multicast VPN are as follows:
1) The support for VPN instance based multicast within each site,
2) The support for public instance based multicast within the public network, and
3) PE devices that support multi-instance multicast:
z
Interfacing with sites and supporting VPN instance based multicast,
z
Interfacing with the public network and supporting public instance based multicast, and
z
Supporting information exchange and data conversion between the public instance and the VPN
instances.
Introduction to MD-VPN