题目内容：
根据下列题干，回答题：Network managers have long awaited practical voice-overIP（ VOIP ）solutions.VOIP promises（ 71 ）network management and decreases costs by（ 72 ）a company's telephony and data infrastructures into one network.And a VOIP solution implemented at a company's head-quarters with far-reaching branch offices can（ 73 ）tremendous amounts of（ 74 ）in long distance phone bills，provided that solution delivers POTS-like voice（ 75 ）over the Internet.
请选择（ 71 ）处最佳答案
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