| FastStartResponse | Structure to store information on fast start response (H.225) to reply same answer in CALL PROCEEDING, ALERTING & CONNECT |
| H245Message | Defines the H.245 message structure |
| OOAliases | This structure is used to hold an H.323 alias address |
| OOCallFwdData | Structure to hold information on a forwarded call |
| ooCallOptions | This structure defines options that can be set at the level of an individual call |
| OOCapPrefs | This structure defines the preference order for capabilities |
| ooGkClient | Structure to store all the configuration information for the gatekeeper client |
| OOH225MsgCallbacks | This structure holds the various callback functions that are triggered when H.225 messages are received or constructed |
| OOH323CALLBACKS | This structure holds all of the H.323 signaling callback function addresses |
| OOH323CallData | This structure is used to maintain all information on an active call |
| OOH323Channel | Structure to store information on an H.323 channel (H.225 or H.245) for a particular call |
| OOH323EndPoint | Structure to store all configuration information related to the endpoint created by an application |
| ooH323EpCapability | Structure to store information related to end point capability |
| OOH323Ports | This structure is used to define the port ranges to be used by the application |
| OOLogicalChannel | Structure to store information on logical channels for a call |
| OOMediaInfo | Structure to store local and remote media endpoint info for a given media type |
| OOStackCommand | This structure is used to queue a stack command for processing in the event handler loop |
| Q931Message | Q.931 message structure |
| RasCallAdmissionInfo | Call Admission Information |
