- * Send a reset message back to send of TCP segment ti,
- * with ack, seq and flags fields as specified by parameters.
+ * Send a single message to the TCP at address specified by
+ * the given TCP/IP header. If flags==0, then we make a copy
+ * of the tcpiphdr at ti and send directly to the addressed host.
+ * This is used to force keep alive messages out using the TCP
+ * template for a connection tp->t_template. If flags are given
+ * then we send a message back to the TCP which originated the
+ * segment ti, and discard the mbuf containing it and any other
+ * attached mbufs.
+ *
+ * In any case the ack and sequence number of the transmitted
+ * segment are as specified by the parameters.