【正文】
( 65) rmi applet 中國(guó)最大的管 理 資料下載中心 (收集 \整理 . 大量免費(fèi)資源共享 ) 第 9 頁 共 10 頁 ●works can be interconnected by different devices in the physical layer works can be connected by __(66)__ or hubs .which just move the bits from one work to an identical work. one layer up we find bridges and switches which operate at data link layer. they can accept __(67)__ examine the mac address and forward the frames to a different work while doing minor protocol translation in the process in me work layer ,we have routers that can connect two works, if two works have __(68)__ work 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 __(69)__ .as an example, gateways between inter and must __(70)__ the message and change various header fields. ( 66) ( 67) ( 68) ( 69) ( 70) ●the purpose of the requirements definition phase is to produce a clear, plete, consistent, and testable __(71)__ of the technical requirements for the software product. during the requirements definition phase, the requirements definition team uses an iterative process to expand a broad statement of the system requirements into a plete and detailed specification of each function that the software must perform and each __(72)__ that it must meet. the starting point is usually a set of high level requirements from the __(73)__ that describe the project or problem. in either case, the requirements definition team formulates an overall concept for the system and then defines __(74)__ showing how the system will be operated publishes the system and operations concept document and conducts a system concept review(scr). 中國(guó)最大的管 理 資料下載中心 (收集 \整理 . 大量免費(fèi)資源共享 ) 第 10 頁 共 10 頁 following the scr, the team derives __(75)__ requir