非对称数字用户线ADSL是采用(11)调制通过双绞线向用户提供宽带业务、交互式数据业务和普通电话服务的接入技术，其上行速率为640Kbit/s～1Mbit/s，下行速率为 1Mbit/s～(12)，有效传输距离为3-5km。ADSL接入互联网的两种方式是：(13)。

 CableModem又叫线缆调制解调器，它可以连接用户家中的PC和(14)网络。Cable Modem的最高上行速率可达(15)，下行速率则更高，彻底解决了由于声音、图像传输而引起的阻塞。

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In low-speed network, it is usually adequate to wait for congestion to occur and then react to it by telling the source of packets to slow down. In high-speed networks, this approach often works poorly, because in the(71)between sending the notification and notification arriving at the source, thousands of additional(72)may arrive. In ATM network, a major tool for preventing(73)is(74)control. When a host wants a new virtual(75),it must describe the traffic to be offered and the service expected.

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To a router, a flow is a(66)of packets that share the same Characterstics, such as traveling the same(67),using the same(68),having the same kind of security, and so on. A router that supports the handling of flow labels has a(69)table. The table has an entry for each active flow label; each entry defines the(70)required by the corresponding flow label.

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