此論文中我們提出一個 UNIX-based 作業系統下之多使用者網路音效系統架構並實際實作證明其可行性。網路音效系統，主要是在一台電腦執行應用程式，而將聲音經由網路傳送至另一台電腦上。我們的系統有以下之特點；第一，其支援多使用者環境，許多使用者可同時在一台主機上執行播音軟體，而聲音分別傳送至他們個人的電腦上；第二，不需對已存在的播音軟體，作任何的修改或重新編譯動作，也不需額外加入新的函式庫；第三，程式不因媒體之格式或裝置受限，亦即播放程式所支援任何媒體格式皆可播放。MuNAS主要由 system call serializer、audio data relay、audio-sending daemon、audio-receiving daemon及 ack-receiving daemon組成。目前MuNAS已開發完成，並於Linux發行版本 Red Hat 7.2、7.3 、8.0 及9.0都已充分測試。測試過的軟體包括 mpg123 、gtv 、realplay、alsaplayer、shockwave flash player 及 Esound等。根據我們的實驗，MuNAS和Open Sound System相容。這套方法也可應用在作何其他的UNIX-based 作業系統。MuNAS補足UNIX的X window系統並不支援傳遞音源的問題，其中一個重要的運用是使得在Unix下以X window系統為基礎的 thin client系統具有完整多媒體的功能。

We present a scheme for implementing a multiuser, network-transparent audio system (MuNAS) on UNIX-based operating systems. In addition to the basic network audio functionality of transmitting the audio data through a network connection and playing it from another computer, our system has the following important features. First, it is designed to work on multiuser operating systems: several users can activate the network audio system by executing their own audio applications in the same computer and their audio data can be forwarded to different computers simultaneously. Second, existing audio applications do not need to be modified or recompiled, and no additional libraries are required. Third, the program is not restricted to any special form of audio data format or device type; i.e., the audio applications can arbitrarily define their own audio data formats and device types. The implementation of the MuNAS comprises making some audio data relays for users, embedding a system-call serializer in the kernel of the UNIX operating system, and executing daemon processes in the audio-sending , audio-receiving and ack-receiving computers. We have implemented MuNAS in Red Hat Linux 7.2 , 8.0 and 9.0, and have tested the implemented system using audio applications including mpg123, gtv, mplayer, realplayer, alsaplayer, shockwave flash player, record, and Esound etc. According to our experiment, the MuNAS is compatible to the Open Sound System. The scheme proposed can be applied to any UNIX-based operating system. MuNAS solves the problem that the X Window system does not support the transmission of audio data , and one of most application is that we have complete function of multimedia in thin-client system based on X window system of UNIX.

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