It sets up encryption, integrity verification, and (optionally) compression and exposes to the upper layer an API for sending and receiving plain text packets.

它设置加密、完整性验证和(可选)压缩并向上层公开一个用于发送和接收纯文本数据包的API。

youdao

There is really no loss in doing this, and SSH even (optionally) adds its own compression layer to enhance performance.

做到这一点真的没有任何损失，而且 SSH 甚至（可选地）添加其自己的压缩层来增强性能。

youdao

The quintessence of the information could be obtained through the compression before the bottle-neck layer and the decompression after that.

输入信息通过瓶颈层前的压缩及瓶颈层后的解压缩过程，信息中的精华将被提取。

youdao

Some have even gone as far as to state that Sony's strategy of using MPEG-2 and uncompressed PCM audio on single-layer Blu-ray discs may have required too much video compression, resulting in early releases that don't match the sharpness of VC-1 encoded movies available on HD DVD.

ENGADGET: Pre-release Blu-ray impressions roundup HD