Comtech EF Data VMS v3.12.x Vipersat - Manual (Page 424)

N:M Hub Modem Redundancy MN/22156, rev 12
C-14 VMS User Guide
N:M Hub Modem Redundancy
Description
The N:M Hub Modem Redundancy service provides for the protection of criti-
cal VMS network modems operating in Hub mode and enhances overall
network reliability.
The N:M redundancy in VMS version 3.x has the following characteristics:
• Protects Vipersat Hub modems from equipment failure
• Is a VMS controlled feature
• Does not require any external switching hardware
• Preserves the satellite network configuration and state information during
hardware failure
• Is scalable and flexible to satisfy the unique requirements of each network
N:M redundancy increases reliability by backing up critical primary central hub
components with standby backup units. In a traditional 1:1 or 1:N redundancy,
switching is handled by combining transmission equipment into logical
mechanical switching units. These software/hardware units then interconnect
the primary transmission units I/O through a physical mechanical maze of
relays and cable jungles. They also become the next point of failure in the reli-
ability hierarchy.
The Vipersat solution relies less on a mechanical backup system architecture,
decreasing the single point of failure. The Vipersat software-driven N:M redun-
dant architecture is completely IP packet controlled with the only hardware item
being an IP controlled electrical power switch.