题目内容
Networks can be interconnected by different devices. In the physical layer, networks can be connected by (11) or hubs, which just move the bits from one network to an identical network. One layer up we find bridges and switches, which operate at data link layer. They can accept (12) ,examine the MAC address, and forward the frames to a different network while doing minor protocol translation in the process. In the network layer, we have routers that can connect two networks. If two networks have (13) network layer, the router may be able to translate between the packer formats. In the transport layer we find transport gateway, which can interface between two transport connections. Finally, in the application layer, application gateways translate message (14) . As an example, gateways between Internet e-mail and X.400 e-mail must (15) the e-mail message and change various header fields.
查看答案
搜索结果不匹配？点我反馈
更多问题
氯化钠
The Rational Unified Process (RUP) is a software engineering process, which captures many of best practices in modern software development. The notions of (21) and scenarios have been proven to be an excellent way to capture function requirements. RUP can be described in two dimensions - time and content. In the time dimension, the software lifecycle is broken into cycles. Each cycle is divided into four consecutive (22) which is concluded with a well-defined (23) and can be further broken down into (24) - a complete development loop resulting in a release of an executable product, a subset of the final product under development, which grows incrementally to become the final system. The content structure refers to the disciplines, which group (25) logically by nature.
A typical (36) language contains an applicative sub-language which approximates the mathematical abstractions of "timeless" functions applied to’ "spaceless" values, where the actual operation sequences and use of storage space during expression evaluation are organized behind the (37) . In this setting, values are data structures of low volume, typically a few computer words or less, which means that an illusion of spacelessness can be realized by having (38) results during expression evaluation stored at the discretion of the language implementation, and effecting parameter (39) and (40) operations through value copying.
Soon, more of the information we receive via the Internet could come (31) in digital wrappers. Wrappers are made up (32) software code that’s targeted to do specific things with the data (33) within them, such as helping to define queries for search engines. They also keep (34) from (35) access to that code.
微信支付 
支付宝支付