+ /// Open a reliable stream channel to another node.
+ /** This function is called whenever a remote node wants to open a channel to the local node.
+ * The application then has to decide whether to accept or reject this channel.
+ *
+ * This function sets the channel receive callback to channel_receive_trampoline,
+ * which in turn calls channel_receive.
+ *
+ * This function sets the channel poll callback to channel_poll_trampoline, which in turn
+ * calls channel_poll. To set a different, channel-specific poll callback, use set_channel_poll_cb.
+ *
+ * @param node The node to which this channel is being initiated.
+ * @param port The port number the peer wishes to connect to.
+ * @param data A pointer to a buffer containing data to already queue for sending.
+ * @param len The length of the data.
+ * @param flags A bitwise-or'd combination of flags that set the semantics for this channel.
+ *
+ * @return A handle for the channel, or NULL in case of an error.