4. If 30% of packets have a size of 64 bytes, 50% of packet has a size of 1500 bytes, and the rest have a size uniformly distributed between 64 and 1500 bytes, what is the maximum number of aggregated packets per second (pps) at a router with 12 links each of 10 Gbps?4.如果30%数据包的大小为64字节,50%分组的大小1500字节,其余的大小均匀分布在64和1500字节之间,则在一台拥有12条10Gbps链路的路由器上每秒汇聚数据包的最大数量(PPS)是多少?
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5. Suppose there are 3,000,000 new phone call arrivals per minute to the switched telephone system worldwide, with each call lasting for 5 minutes on average, and there are 6 hops (i.e. 6 links and 6 nodes) on average between the callers and callees. How many memory entries are occupied on average to support the switched connectivity worldwide?5.假设每分钟有300万个新的电话呼叫到达全球范围的电话交换系统,平均每次通话长达5分钟,并且每个呼叫用户和被叫用户之间平均有6跳(即6条链路和6个节点)。那么为了支持全球交换连接平均需要占用多少内存表项?
6. In a clustering of 4,294,967,296 nodes, if we still want to keep the three-level hierarchy like the one in Figure 1.1,but like to have the same number of group members, groups, and supergroups at the group, supergroup, and “super-supergroup” levels, respectively, what is that number approximately?6.在一个拥有4,294,967,296个节点的集群中,如果仍然要保持像图1.1中所示的三个层次,但仍希望有相同数量的组成员和组,组上的超群组,超组,以及“超超组”层,那么近似的数量是多少?
7. If, due to the shortage of IP addresses, we halve the size at the group and the supergroup levels in Figure 1.1, with at most 128 group members for a group and 128 groups for a supergroup, how many supergroups can we allow?7.如果由于IP地址短缺,我们将图1.1中的组和超组一分为二,每组最多有128个成员每个超组最多有128个组,则最多允许多少这样的超组?
8. Compare the differences in the requirements and principles for data communications and tele(voice)communications. Name the three most important differences and explain.8.比较数据通信和电信(语音)通信的要求和原则之间的差异。对最重要的三个差异进行命名并加以解释。