Comtech EF Data VMS v3.12.x Vipersat - Manual (Page 170)

Network Manager Configuration MN/22156, rev 12
3-70 VMS User Guide
Effect of RF Changes on Reservations
Caution: The operator must be aware that changes made to bandwidth
resources in the RF configuration after reservations have been
defined may require re-evaluating these reservations and resetting
pre-allocated bandwidth.
Reducing or moving a bandwidth pool, for example, may result in a failed
attempt to grant the bandwidth necessary to meet a site’s CIR requirement. Such
a failure would cause the site to become unavailable for switching until reserva-
tions for that site are reset.
Any sites that become unavailable must be reset on an individual basis.
However, for those sites with reservations that have not been made unavailable,
resetting the reservations for one of those sites will result in all of them being
reset. To reset site reservations, perform the following steps:
1. Open the Properties for the Remote site and select the InBand Reservations
dialog.
2. Click on the check box to de-select the satellite for this bandwidth reserva-
tion, then click again to re-select the satellite.
3. Click on Apply, then Close the window.
The VMS will reset the pre-allocated resources for this Remote, as well as
all other Remotes with guaranteed bandwidth settings that are still available.
Set InBand Modulation and Coding
Advanced Switching Overview
With the VMS Advanced Switching feature, the operator has the option of
configuring multiple levels of modulation types and FEC code rates within the
dynamic SCPC operation. Thus, more efficient bandwidth utilization can be
realized.
An advanced switching table can be constructed for a remote modulator where
specified modulation types and FEC code rates are paired with set data rates.
Each data rate is associated with a Mod/Code and, as the system achieves the set
rate, the transmission is modified to the new higher- or lower-order modulation
setting specified for that rate. For each table entry, the VMS calculates an opti-
mized switching threshold that the system uses to assign the most efficient
bandwidth in an advanced switching environment.