40
Figure 2 Full-mesh network
NHS-NHC network—NHCs cannot establish tunnels between each other. Instead, they
establish tunnels with the NHS. The NHS forwards data for the NHCs. The NHS acts as both
the routing information exchange center and the data forwarding center.
Figure 3 NHS-NHC network
A mGRE tunnel is as established as follows:
NHC-NHS tunnel establishment process:
An NHC-NHS tunnel is established in the registration process. During registration, the
NHC-NHS tunnel is in initialization state. After registration succeeds, the NHC-NHS tunnel is in
success state.
Site 1 Site
2
NHS
NHC 1
Public network
NHC
2
Data
NHS
-
NHC
NHS
-
NHC
NHC-NHC
Site 1 Site 2
NHS
NHC 1
Public network
NHC 2
Data
Data
NHS-NHC
NHS-NHC