题目内容：
根据下列题干，回答题Communication protocols are (1) connection-oriented or connectionless， (2) whether the sender of a message needs to contact and maintain a dialog with the recipient or (3) send a message without any prior connect and with the hope that the recipient receives everything (4) .These methods (5) the two ways that communication is implemented on networks.
请选择（1）处最佳答案
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