For connective transports, which maintain actual connections, SST defines two well understood behaviors: client and server. Their difference lies in how new connections are obtained. Server behavior allows both active solicitation and initiation of new connections with other endpoints. Client behavior allows only the initiation of new connections. Thus, two endpoints with client transport behavior will not be able to communicate with one another.
In the TCP world, for example, a server transport would have a listening socket waiting for incoming connect operations. A client TCP transport does not have a listening socket as it has no requirement to facilitate incoming connections. All transports which are not client transports are assumed to support server transport behavior.
Connective transports provide the following callbacks: