根据下面的文字资料回答 63~67 题In low－speed network,it is usually adequate to wait for co

根据下面的文字资料回答 63～67 题

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 oftenworks poorly，because in the（ 1 ）between sending the

notification and notification arriving at the source，thousands of

additional（ 2 ）may aITive．In ATM network，a major tool for

preventing（ 3 ）is（ 4 ）control．when a host wants a new virtual（ 5 ），it must

describe the traffic to be offered and the service expected．

第63题：文中（ 1 ）处正确的答案是（ ）。

A．interval

B．time

C．slot

D．delay

A【正确答案】：A 【参考解析】：在低速网络中，通常采用碰到拥塞时，通过向源端反映其降低发送速率。而在告诉网络中，这种方式将会恶化，因为在发送通告和通告到达之间会有成千上万的其它数据包到达。在ATM网络中，主要采用允许控制来避免拥塞，当有一台主机要建立一条新的虚连接时，它必须描述它所需的流量和服务等级。