Comtech EF Data MIDAS 4 System and Design - Manual (Page 29)

System and Design Manual, Revision 2
Solutions 2–5
User Port Triggered
In addition to RTS/DTR triggered circuit setup and termination, customer
equipment also can be programmed to send circuit setup and termination
requests to the Node Control Modem via the user port. When a circuit is
required, the customer equipment sends the setup request to the Node Control
Modem via the user port.
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 circuit, and returns the bandwidth to the free pool.This allows
for optimal bandwidth usage without user intervention.
IP Route
For IP enabled Comtech EF Data products, such as the CiM-550, there is a
third method for automatic circuit establishment. The CiM-550 can be
configured with one or more routes.
• When IP packets from the customer’s LAN enter the 10/100 BaseT
Ethernet port of the CiM-550, the destination IP address of the packet
is checked for a match in its satellite route table.
• Upon finding a match, the CiM-550 Modem requests circuit
establishment to a pre-determined destination through the MIDAS
Node Controller, which assigns bandwidth and transmit power
followed by circuit establishment.
• After a user configurable period of time expires where the presence of
IP packets destined for a satellite route are absent, the CiM-550 will
request circuit termination from the MIDAS Node Controller,
releasing associated resources.
These automatic circuit request methods allow for optimal bandwidth usage
without user intervention.