The polling interval is the period of time of completion of a network request to the gateway.
The window size is relevant for Asynchronous protocols (such as SMPP) and defines the max allowed number of unacknowledged operations.
Enabling this setting allows messages to be sent more rapidly over an SMPP connection. While Async modes is enabled then it does not need to wait for an acknowledgement for the previous message before submitting the next message. We also support Async mode, for the faster submission of the traffic.