Summary
1. What was the primary reason(s) for the development of store and forward networks by the academic community?
- By breaking communications that traversed long distances into multiple hops using shorter leased lines and stopping at many universities along the way, overall cost was minimized.
- Universities were willing to tolerate delay in order to keep the cost of long-distance data communication low
- Due to a limited number of installed copper wires, transfer with leased lines was expensive
2. What is the relationship between the number of hops on the store and forward network, and the time taken for a message to be delivered?
- More hops within the network result in a longer delivery time
3.What were the primary motivations for the Department of Defense to develop the research network ARPANET?
- To improve computing equipment for military purposes, making it easier for people to access computers, and communicate more effectively across the military.
4. What was the fundamental difference between the store and forward network of BITNET, and ARPANET?
- Packet switching
5. In the shared network, the role of the router is:
- To quickly forward packets to the next router
6. What are the advantages of packet switching? (Choose all that apply)
- Many messages can be in-flight at the same time, preventing large messages from blocking small ones
- Packets can take more than one path from the source to destination bypassing slow or down links in the network
7. Why did the National Science Foundation decide to build a national shared network?
- It was very expensive to give each university its own supercomputer. A national shared network was more affordable.
8. Larry Smarr was one of many instrumental players in creating the first national network. What do we learn from his interview?
- That high performance computing needs at universities and the Internet were deeply connected
9. Why did the University of Michigan not participate in the ARPANET research project?
- Michigan had its own state-wide network, consisting of 3 nodes
10. In the late 1980s, how did the first average citizens get Internet access?
- Average citizens could purchase Internet access commercially
- ARPANET became the first Internet Service Provider (ISP) and sold access to the NSFNet
11. What was the primary difference between the University of Michigan proposal to build the NSFNet, and the other proposals?
- The University of Michigan proposal proposed a 1.54 Mbit network with planned upgrades to much higher speeds throughout the life of the project
- The University of Michigan Proposal used partnerships to deliver $55Million of value for $15M of NSF funds awarded.
原文地址：http://www.cnblogs.com/jqhuang2021/p/16837344.html
