TAILIEUCHUNG - Internetworking with TCP/IP- P46

Internetworking with TCP/IP- P46: TCP/IP has accommodated change well. The basic technology has survived nearly two decades of exponential growth and the associated increases in traffic. The protocols have worked over new high-speed network technologies, and the design has handled applications that could not be imagined in the original design. Of course, the entire protocol suite has not remained static. New protocols have been deployed, and new techniques have been developed to adapt existing protocols to new network technologies | Sec. RARP Server 409 There are two significant differences between a RARP server and a UDP echo or time server. First RARP packets travel across the physical network directly in hardware frames not in IP datagrams. Thus unlike the UDP echo server which allows a client to contact a server anywhere on an internet the RARP server requires the client to be on the same physical network. Second RARP cannot be implemented by an application program. Echo and time servers can be built as application programs because they use UDP. By contrast a RARP server needs access to raw hardware packets. Alternatives To The Client-Server Model What are the alternatives to client-server interaction and when might they be attractive This section gives an answer to these questions. In the client-server model programs usually act as clients when they need information but it is sometimes important to minimize such interactions. The ARP protocol from Chapter 5 gives one example. It uses a modified form of client-server interaction to obtain physical address mappings. Machines that use ARP keep a cache of answers to improve the efficiency of later queries. Caching improves the performance of clientserver interaction in cases where the recent history of queries is a good indicator of future use. Although caching improves performance it does not change the essence of clientserver interaction. The essence lies in our assumption that processing must be driven by demand. We have assumed that a program executes until it needs information and then acts as a client to obtain the needed information. Taking a demand-driven view of the world is natural and arises from experience. Caching helps alleviate the cost of obtaining information by lowering the retrieval cost for all except the first process that makes a request. How can we lower the cost of information retrieval for the first request In a distributed system it may be possible to have concurrent background activities that collect and .

TỪ KHÓA LIÊN QUAN
TAILIEUCHUNG - Chia sẻ tài liệu không giới hạn
Địa chỉ : 444 Hoang Hoa Tham, Hanoi, Viet Nam
Website : tailieuchung.com
Email : tailieuchung20@gmail.com
Tailieuchung.com là thư viện tài liệu trực tuyến, nơi chia sẽ trao đổi hàng triệu tài liệu như luận văn đồ án, sách, giáo trình, đề thi.
Chúng tôi không chịu trách nhiệm liên quan đến các vấn đề bản quyền nội dung tài liệu được thành viên tự nguyện đăng tải lên, nếu phát hiện thấy tài liệu xấu hoặc tài liệu có bản quyền xin hãy email cho chúng tôi.
Đã phát hiện trình chặn quảng cáo AdBlock
Trang web này phụ thuộc vào doanh thu từ số lần hiển thị quảng cáo để tồn tại. Vui lòng tắt trình chặn quảng cáo của bạn hoặc tạm dừng tính năng chặn quảng cáo cho trang web này.