The CommuniGate Pro SMPP Module implements the SMPP protocol functionality. When the Server Administrator specifies one or several SMPP servers (SMSC systems), the SMPP Module opens a TCP connection to the specified server address and "binds" using the specified credentials. When an IM Signal is routed to the SMPP Module, the Module finds the SMPP server it is routed to, and sends it to that server via the SMPP connection.
To maintain a connection when it is idle (no IM Requests to relay), the module periodically sends the enquire_link request to the SMPP server.
If a connection to the server cannot be established, or it has been broken and it is being re-established, the IM Signals are enqueued. They are relayed to the server when a connection is established.
The SMPP module processes only the MESSAGE Real-Time requests, all other requests are rejected.