Comtech EF Data VMS v3.12.x Vipersat - Manual (Page 427)

Appendix C - Redundancy C-17
MN/22156, rev 12 N:M Hub Modem Redundancy
• The VMS, managed power strip, and hub modems must be on the same
LAN segment
• All modems must share the same RF infrastructure, such as combiners and
splitters
Once devices have been installed in the satellite network as described in the
section “Installing N:M Redundancy” on page C-16, a group of identical,
active, primary devices functioning in the satellite network under VMS control
and another group of N devices, identical to the active devices in a spare device
pool are created.
Tip: The logical grouping should correspond to the physical device grouping
and their connections to remote managed power controls.
The devices in the primary group are devices which are active in the network.
These devices can be performing any function in the network, except expansion
units. All of the devices in the backup group are turned on, but have not been
configured to perform any network function and are assigned a different IP
addresses than the active devices. All devices in both the active and spare
groups are connected to the VMS managed power switch as shown in
figure C-10.