Comtech EF Data MIDAS 4 System and Design - Manual (Page 28)

System and Design Manual, Revision 2
2–4 Solutions
The Node Control Modem sends the request to the MIDAS Controller, which
assigns bandwidth and transmits power followed by circuit establishment.
When the circuit is no longer required, the customer equipment sends the
termination request to the Node Control Modem. The Node Control Modem
terminates the circuit locally and informs the MIDAS Controller, which
terminates the satellite circuit, and releases associate resources.
MIDAS Operator
Workstation
The MIDAS operator can request the establishment and termination of a data
circuit via the operator workstation. Through the GUI, a user can define a CKT
with configurable parameters, such as Power Level, Modulation, FEC, and
others.
Button Results
ENABLE The user can establish the CKT.
DISABLE The user can teardown the CKT
DELETE The user can reuse the CKT.
Automatic Request
RTS/DTR Triggered
Customer equipment such as routers can request circuit establishment and
termination via a transition on the RTS/DTR line or by sending user port
commands to the Node Control Modem. Comtech EF Data products such as
the CiM-550 can be configured to request circuit establishment when an IP
packet destination matches a satellite route in the CiM-550.
The router activates the RTS/DTR line when it requires a circuit to a pre-
defined destination. The node control modem detects the traffic modem’s
activated RTS/DTR signal. A request for circuit establishment to the pre-
determined destination is sent to the MIDAS Controller, which assigns
bandwidth and transmit power followed by circuit establishment. When the
circuit is no longer required, the router sets the RTS/DTR inactive. The Node
Control Modem terminates the circuit locally and informs the MIDAS
Controller, which terminates the satellite circuit, and releases associated
resources.