Comtech EF Data VMS v3.12.x Vipersat - Manual (Page 508)

Operational Procedures MN/22156, rev 12
F-10 VMS User Guide
Figure F-5 Remote Alarm Count
Link Statistics
Hub Demodulator Eb/No
One of the main preferences is to correlate the Eb/No for the Hub demodulator
of a switched Remote modulator. This can be obtained by querying the modem
via the proxy for the "unitInbandReturnPathEbN0" variable in the switching
MIB. This variable is designed to look like part of the Remote modem, when in
reality the VMS intercepts the request and fills in the Eb/No of the currently
allocated Hub demodulator.
This allows for a very simple way of monitoring the quality of a dynamic link
without the complexity of multiple queries involving different community
strings.
For example, if the Remote data unit is a CDM-840 with an IP address of
172.18.100.1, the operator would use the VMS as a proxy by directing the
SNMP requests to the VMS using a community string such as
“[email protected]”. Along with querying the Remote modem for standard
values like “cdm840TxFrequency” or “cdm840RxLock”, a request for
“unitInbandReturnPathEbN0” could be used to get the Eb/No of the currently