Comtech EF Data VMS v3.12.x Vipersat - Manual (Page 369)

Chapter 7 - Out-of-Band Units 7-13
MN/22156, rev 12 Switching Out-of-Band Modems
Out-of-Band Circuit Manager (OBCM)
General
OBCM is utilized for switching OOB units, whether they are SNMP units or
Vipersat-enabled units.
Circuits are first created (using the OOB Circuit Wizard), then they are manu-
ally switched by either using the Setup command in ViperView, or via a sched-
uled switch that has been configured in ArrangeLink. Switching can be initiated
from the Virtual Network Operator interface as well.
There are three circuit types that can be designated:
• Half Duplex (Broadcast / Point-to-Multipoint) — used for applications
where there is no return path or the return path is a low speed terrestrial
link. Typical examples include broadcast video, distant learning, and data
distribution.
• Full Duplex (Point-to-Point) — used for applications that are interactive,
requiring two-way communications, but where the data transport is not
routable IP. Ideal for disaster recovery, satellite news gathering mobile
units with non-IP video equipment, and bulk-encrypted links with no IP
header.
• Custom — provides the ability to define any circuit type, allowing the
operator to specify individual channels in any manner that is required for
the application.
Managed and Unmanaged Devices
Within the OBCM, modem units and their devices (modulators, demodulators)
are designated as either Managed or Unmanaged (also known as Assigned). The
unit/device that is selected as Managed determines what drivers will be used
and what space segment is available for the circuit. The Unmanaged unit/device
is assigned by the operator to complete the circuit. Care must be taken to assign
an appropriate/like unit or device to ensure compatibility. Whether the selection
is based on the unit or the device is a function of the type of circuit that is being
created.
The Full Duplex circuit type uses units instead of devices. This is because this
type requires that the managed modulator and demodulator both belong to the
same modem unit, and the unmanaged modulator and demodulator at the other
site also belong to the same modem unit. In contrast, the Half Duplex and
Custom circuit types use devices for designation as managed or unmanaged.
An OOB circuit consists of one or more channels. A channel is defined as the
connection between a modulator and at least one demodulator, consisting of the
channel bit rate, priority and, when using Vipersat-enabled modems, an Extra