新词集锦(428)

Steganography

A method of embedding electronic messages into a media file (for example, an image or audio file) by altering nonessential lines of code; the changes are imperceptible. The message remains undetected until unencrypted.

IP PBX

An IP PBX is a private branch exchange (telephone switching system within an enterprise) that switches calls between VoIP users on local lines while allowing all users to share a certain number of external phone lines. The typical IP PBX can also switch calls between a VoIP user and a traditional telephone user, or between two traditional telephone users in the same way that a conventional PBX does. With a conventional PBX, separate networks are necessary for voice and data communications. One of the main advantages of an IP PBX is the fact that it employs converged data and voice networks. This means that Internet access, as well as VoIP communications and traditional telephone communications, are all possible using a single line to each user. This provides flexibility as an enterprise grows, and can also reduce long-term operation and maintenance costs.

密写术

通过修改无关紧要的程序行，将电子信息嵌入媒体文件(如图像或声音文件)的方法，这些变化是觉察不到的。只要不解密，嵌入的信息是查不出的。

IP专用小交换机

IP PBX是专用小交换机(即企业内的电话交换系统)，交换本地线路上VoIP用户之间的电话，同时允许所有的用户共享一定数量的外线。典型的IP PBX还能交换VoIP用户与传统电话用户之间的电话，或者以常规PBX一样的方法交换两个传统电话用户之间的电话。用常规PBX时，话音和数据通信必须有两个分开的网络。IP PBX主要的优势之一就是它使用合并的数据与话音网络。这意味着对每个用户而言他能用单条线路进行上网、VoIP通信和传统电话通信。当企业扩大时，这就提供了灵活性，同时降低了长期的运行和维护费用。