The simplified block diagram below shows the basic software architecture of the DC-MGCP and DC-Megaco/H.248 protocol products. Functional blocks showing MIBs, support code etc have been omitted for clarity.
For an overview of the DC-MGCP and DC-Megaco/H.248 software and its features, see DC-MGCP / DC-Megaco Product Overview.
In the above architecture, the Transport Layer component, the Association Management component and the Transaction Manager component are common between DC-MGCP and DC-Megaco. The Message Support Library is largely protocol-specific although some parts are common.
The Message Support Library is a stand-alone library, and while it is required by the other DC-MGCP or DC-Megaco components, it may be used on its own without them if required.
The DC-MGCP / DC-Megaco product architecture is highly modular, allowing OEMs to reduce core product and package footprint to the minimum required for a particular application.
DC-MGCP and DC-Megaco/H.248 Software Interfaces
There are four key interfaces between the application and the DC-MGCP and DC-Megaco/H.248 software, which are largely common for both MGC and MG components.
Association Management Interface
The Association Management Interface provides the following services.
- Managing associations, including creation and destruction (through calls to the Transport Layer) and informing the MG/MGC of association state changes.
- Managing default MGs, including initiating connections, handling retries and (if necessary) trying configured alternatives.
Transaction Management Interface
The Transaction Management Interface provides the following services.
- Sending sets of commands to a peer and receiving responses.
- Receiving sets of commands from a peer and constructing appropriate responses.
Message Support Library Interface
The Message Support Library Interface provides the following services for use by applications and core code.
- Message and parameter parsing
- Parsing and extraction of parameters from SDP format Session Descriptors
- Message construction
- Parameter decoding
Helper Function Interface
The Helper Function Interface simplifies the handling of event requests and notifications, providing callbacks to the application to instruct it to
- activate or deactivate notification of an event
- apply or cancel a signal.
Transport Layer Interface
In addition to the above interfaces, the OEM application can interface directly to the Transport Layer. This is largely a raw send message / receive message interface although the Transport Layer does provide monitoring of messages for reliable transport and duplicate detection functions.
For more information about Data Connection's MGCP and Megaco/H.248 products and expertise contact dcmgcp@dataconnection.com.