Modem Resetting and Management of Channel Allocation

Modem Resetting

The Channel Manager always attempts to place the modem into a known state prior to attempting the Connect string. Thus, the hard-coded DTR reset and ‘+++ATH’ messages are sent prior to both Connect and Disconnect strings.

Management of Channel Allocation

The modem list is managed as a circular queue of available resources. A global pointer is used to identify the last allocated modem resource. When a new request is sent to the Channel Manager it searches for the next available modem from the position of the global pointer. When an available channel is found, the Channel Manager updates the global pointer and attempts to perform channel communications. Note that the next available modem is simply the next outbound or inbound/outbound modem of the correct type which is in-service and is not currently in use by the Channel Manager.