Send PolicyIn the absence of both pushed data and a closed transmission window (see Figure 17.3a), a sending TCP entity is free to transmit data at its own convenience. As data are issued by the user, they are buffered in transmit buffer. TCP may construct a segment for each batch of data provided by its user or it may wait until a certain amount of data accumulates before constructing and sending a segment. The actual policy will depend on performance considerations. If transmissions are infrequent and large. there is low overhead in terms segment generation and processing. On the other hand, if transmissions are frequent and small, then the system is providing quick response.
參考答案:传送规则
在压入堆栈数据和关闭传输窗口的空闲时间（见图 17.3a），就TCP协议的传输者（传输机）本身来说处于空闲状态，可以传送数据。当数据被使用者（用户）接收后，它们（指数据）存储在传输缓冲区内。TCP协议可以为每一个数据包建立一个数据段或者等到一定数量的数据积累后才建立和发送一个数据段。实际的协议将根据性能要求来决定。如果数据传输数量很少而（每次传输的）数据量很大，在数据段建立和处理的过程中将有堵塞。另一种情况，如果数据传输次数频繁而数据量小，系统将提供快速的响应。
